# Help center > Your central resource for Fernox App support and guidance ## On-Site Water Tests Guides and Information covering our on-site testing range. - [On-Site Tests Countries & Availability](https://help.fernox.app/en/articles/65-on-site-tests-countries-and-availability): The table below shows the availability of each Fernox water test in different countries. Please note that our test availability is currently limited to certain countries as we transition our apps to provide you with an even smoother experience. We appreciate your patience during this process. Rest assured, we are working hard to expand our service to more countries and add additional test types in the near future. - [On-Site Test Parameters](https://help.fernox.app/en/articles/129-on-site-test-parameters): Instant System Testing Parameters ## On-Site Water Tests > Instant System Test - [IST Testing Parameters](https://help.fernox.app/en/articles/105-ist-testing-parameters): Instant System Testing Parameters - [IST Contents & Preparation](https://help.fernox.app/en/articles/127-ist-contents-and-preparation): The Instant System Test is a convenient, easy-to-use method of testing the system water quality at the job site. After testing a PDF certificate will be generated automatically and sent to customers and chosen contacts. - [IST Fernox App Guide](https://help.fernox.app/en/articles/67-ist-fernox-app-guide): After downloading the app and completing registration, you can create a new Instant System Test by following the steps below or watching the video guide. ## On-Site Water Tests > Express Inhibitor Test - [EIT Testing Parameters](https://help.fernox.app/en/articles/126-eit-testing-parameters): Express Inhibitor Test Testing Parameters - [EIT Contents & Preparation](https://help.fernox.app/en/articles/128-eit-contents-and-preparation): It is an easy to use dip strip that tests central heating systems for the correct concentration of inhibitor, to ensure that the system is fully protected and sludge and debris is prevented from forming and building up. - [EIT Fernox App Guide](https://help.fernox.app/en/articles/71-eit-fernox-app-guide): After downloading the app and completing registration, you can create a new Express Inhibitor Test by following the steps below. ## On-Site Water Tests > FAQ > General Information - [Where can I get an Instant System Test?](https://help.fernox.app/en/articles/69-where-can-i-get-an-instant-system-test): Find and get the Fernox Instant System Test - [When will my results be ready?](https://help.fernox.app/en/articles/43-when-will-my-results-be-ready): For On-Site Tests you will receive an email notification with the results PDF attached a few minutes after submitting the test, and they will also be stored within the Fernox App and Web Portal. - [Where can I get an Express Inhibitor Test](https://help.fernox.app/en/articles/47-where-can-i-get-an-express-inhibitor-test): Find and buy the Fernox Express Inhibitor Test - [Can the test strips be reused?](https://help.fernox.app/en/articles/74-can-the-test-strips-be-reused): No, the strip can be used only once. - [Do I need to be at the site to perform the test?](https://help.fernox.app/en/articles/81-do-i-need-to-be-at-the-site-to-perform-the-test): Yes, you need to be at the site to perform the test. To ensure accurate results, take a sample of system water that is representative of the entire system. Let the water run for a few seconds before collecting the sample. Then, dip the test strip into the water for one second and remove it for analysis. For a detailed, step-by-step guide on how to use the Express Inhibitor Test, please refer to this guide - [How do I take samples for the Instant System Test?](https://help.fernox.app/en/articles/87-how-do-i-take-samples-for-the-instant-system-test): Perform turbidity, corrosion, pH, and inhibitor tests accurately - [How quick is the Express Inhibitor Test?](https://help.fernox.app/en/articles/88-how-quick-is-the-express-inhibitor-test): The Express Inhibitor Test is designed to provide instant results. After dipping the test strip into the system water, you will be able to capture an image and compare the colour within seconds. The results and PDF certificate are generated immediately upon submission. - [How quick is the Instant System Test?](https://help.fernox.app/en/articles/89-how-quick-is-the-instant-system-test): The Instant System Test is designed to provide instant results. The results and PDF certificate are generated immediately upon submission. - [What information do I need to provide when setting up a new test?](https://help.fernox.app/en/articles/99-what-information-do-i-need-to-provide-when-setting-up-a-new-test): You will need to enter customer reference, project reference, company name, address, system details (e.g., type, age, appliance manufacturer, serial number, etc.), and the inhibitor used, among other fields. ## On-Site Water Tests > FAQ > Testing Samples - [What should I do if the pH strip colours don’t match between the container and the app?](https://help.fernox.app/en/articles/66-what-should-i-do-if-the-ph-strip-colours-don-t-match-between-the-container-and-the-app): There are currently two existing versions of our pH strips, each with different colour charts. To ensure an accurate reading, please select the correct pH strip tab in the app before comparing your results. - [What if I can’t find the correct inhibitor in the app’s dropdown menu?](https://help.fernox.app/en/articles/72-what-if-i-can-t-find-the-correct-inhibitor-in-the-app-s-dropdown-menu): If you can’t find the inhibitor, you can manually enter it or search for it using the search function. - [How do I select the inhibitor result?](https://help.fernox.app/en/articles/73-how-do-i-select-the-inhibitor-result): Once the image is captured, you can select the corresponding inhibitor concentration value from the dropdown menu based on the colour comparison. For detailed, step-by-step guides on how to use the Express Inhibitor Test and the Instant System Test, please refer to guides below. - [How do I capture the image of the test strip?](https://help.fernox.app/en/articles/75-how-do-i-capture-the-image-of-the-test-strip): After dipping the strip, use your smartphone or tablet camera to take a photo of the strip within 10 seconds. Align the strip with the bottle to match the colour/ppm value. Ensure the image is focused on the sample, then confirm the result. - [How do I take the sample for the Express Inhibitor Test?](https://help.fernox.app/en/articles/76-how-do-i-take-the-sample-for-the-express-inhibitor-test): To take the sample, simply dip the test strip into the system water for 1 second, remove it, and shake off any excess water. - [Can I save addresses for future tests?](https://help.fernox.app/en/articles/77-can-i-save-addresses-for-future-tests): Yes, the app allows you to save and reuse addresses for convenience. - [What if the test strip result doesn’t match the reference colours?](https://help.fernox.app/en/articles/79-what-if-the-test-strip-result-doesn-t-match-the-reference-colours): Use the app’s cropping and alignment tool to refine the photo, or select the closest matching value manually. - [Is it mandatory to fill in all the fields during test setup?](https://help.fernox.app/en/articles/91-is-it-mandatory-to-fill-in-all-the-fields-during-test-setup): All fields marked with an asterisk (*) are required to complete the test setup. These include customer reference, address, system type, and others. - [What happens after I submit the test?](https://help.fernox.app/en/articles/96-what-happens-after-i-submit-the-test): After you submit the test, you will receive an email with the test results in a PDF format. This email will include the details of the test, a recommendation, and a conclusion based on the results. - [What if the test strip result doesn’t match a pre-set color/ppm value?](https://help.fernox.app/en/articles/97-what-if-the-test-strip-result-doesn-t-match-a-pre-set-colorppm-value): Use the app’s cropping tool to refine the image, or manually select the closest matching value. - [What if the test strip result doesn’t match the reference colours?](https://help.fernox.app/en/articles/98-what-if-the-test-strip-result-doesn-t-match-the-reference-colours): Use the app’s cropping and alignment tool to refine the photo, or select the closest matching value manually. ## On-Site Water Tests > FAQ > Understanding Results - [Does the Express Inhibitor Test check for all inhibitors?](https://help.fernox.app/en/articles/84-does-the-express-inhibitor-test-check-for-all-inhibitors): Yes! The Express Inhibitor Test is a universal test that will check for the presence of all molybdate based inhibitors within the system water. - [How can I keep a record of the pass / fail for each job?](https://help.fernox.app/en/articles/86-how-can-i-keep-a-record-of-the-pass-fail-for-each-job): It is very easy to keep track of test results with the free to download Fernox App, which installers can use to manage and evidence each test. Using the in-app camera, users take a picture of the test strip and select its colour to generate the pass or fail result. Using this process will auto-generate a PDF certificate with the result to your email address and this acts as evidence that the test has been completed and the system is fully protected. For ease, all of your submissions will be stored in your account for you to view and export on demand. If a test fails, installers can also demonstrate that action has been taken and the system subsequently re-tested to receive a positive result. - [What is pH within a heating system, and why is it important?](https://help.fernox.app/en/articles/102-what-is-ph-within-a-heating-system-and-why-is-it-important): In a heating system, pH refers to the measure of how acidic or alkaline the water within the system is. It is an important parameter because the pH of the water can significantly affect the performance, longevity, and efficiency of the system. ## On-Site Water Tests > FAQ > Advice - [After adding inhibitor to the system how long should I wait before re-testing the system water?](https://help.fernox.app/en/articles/80-after-adding-inhibitor-to-the-system-how-long-should-i-wait-before-re-testing-the-system-water): With the initial dose, its key to make sure the system water is circulated properly so that the inhibitor is sufficiently mixed. Fernox recommend that you let the system circulate for at least 15 minutes. Also having the system on hot will help speed this up. - [What Fernox products can I use to re-dose the system?](https://help.fernox.app/en/articles/95-what-fernox-products-can-i-use-to-re-dose-the-system): If the dip test shows less than 100ppm, installers can immediately resolve the issue by adding a high-quality inhibitor such as Fernox Protector F1 or where a filter is fitted, Protector+ Filter Fluid. The test can be re-taken once the inhibitor has circulated to confirm the level has been met. - [What types of inhibitors can the Express Inhibitor Test detect?](https://help.fernox.app/en/articles/108-what-types-of-inhibitors-can-the-express-inhibitor-test-detect): The test can detect all Fernox Protectors, as well as other molybdate-based inhibitors used in central heating systems. ## Postal Water Tests Guides covering the various Fernox postal water testing products. - [Postal Tests Countries & Availability](https://help.fernox.app/en/articles/64-postal-tests-countries-and-availability): The table below shows the availability of each Fernox water test in different countries. Please note that our test availability is currently limited to certain countries as we transition our apps to provide you with an even smoother experience. We appreciate your patience during this process. Rest assured, we are working hard to expand our service to more countries and add additional test types in the near future. - [Postal Test Comparison](https://help.fernox.app/en/articles/111-postal-test-comparison): The table below shows the various chemical testing parameters for the postal Fernox water testing products. ## Postal Water Tests > Diagnostic Water Test - [DWT Testing Parameters](https://help.fernox.app/en/articles/20-dwt-testing-parameters): Measures 46 water quality parameters, including mains water data, to provide a comprehensive analysis of the system water and identify potential issues. - [DWT Contents & Preparation](https://help.fernox.app/en/articles/116-dwt-contents-and-preparation): The Diagnostic Water Test is a comprehensive postal laboratory test for heating system water, providing a detailed analysis of the system and fill water samples. For a detailed, step-by-step guide on how to use the Diagnostic Water Test, please refer to the guide below. - [DWT Fernox App Guide](https://help.fernox.app/en/articles/125-dwt-fernox-app-guide): After downloading the App and completing registration, you can start adding a ‘New Diagnostic Water Test’. - [DWT International Postage Instructions](https://help.fernox.app/en/articles/118-dwt-international-postage-instructions): For customers located outside the UK, this page provides information on how to return your completed Diagnostic Water Test sample to our laboratory. Once you’ve taken your water sample and completed the test, you can use the international postage options available for sending your sample back to us. Whether you’re in Europe or North America, you’ll find the shipping details and instructions here to ensure your sample reaches us securely and promptly. ## Postal Water Tests > Water Quality Test - [WQT Testing Parameters](https://help.fernox.app/en/articles/113-wqt-testing-parameters): Measures 16 water quality parameters to provide an overview of the system water and help identify potential water quality issues. - [WQT Contents & Preparation](https://help.fernox.app/en/articles/117-wqt-contents-and-preparation): The Water Quality Test is a comprehensive postal laboratory test for heating system water, providing a detailed analysis of the system and fill water samples. For a detailed, step-by-step guide on how to use the Water Quality Test, please refer to the guide below. - [WQT Fernox App Guide](https://help.fernox.app/en/articles/124-wqt-fernox-app-guide): After downloading the app and completing registration, you can create a new Water Quality Test by following the steps below or watching the video guide. ## Postal Water Tests > System Health Check - [SHC Testing Parameters](https://help.fernox.app/en/articles/112-shc-testing-parameters): Measures 26 parameters to provide a comprehensive overview of the heating system and help identify potential issues affecting system performance, water quality and protection. - [SHC Contents & Preparation](https://help.fernox.app/en/articles/123-shc-contents-and-preparation): The System Health Check is a premium postal sampling service that diagnoses central heating issues with laboratory precision, enabling the correct action to be taken. - [SHC Paper Form](https://help.fernox.app/en/articles/144-shc-paper-form): Replacement System Health Check Results Form ## Postal Water Tests > Commercial Water Quality Test - [CQT Testing Parameters](https://help.fernox.app/en/articles/114-cqt-testing-parameters): Measures 27 water quality parameters to provide a comprehensive analysis of commercial heating system water and help identify potential water quality issues. - [CQT Contents & Preparation](https://help.fernox.app/en/articles/121-cqt-contents-and-preparation): The Commercial Water Quality Test is a paperless, smart phone driven, postal laboratory service designed for commissioning monitoring, and maintaining commercial heating systems. Once the sample has completed laboratory testing, the system will generate a PDF certificate which will be automatically sent to the user that submitted the sample in the mobile application. All the submissions will be stored in your account, so you can access them whenever you want from the mobile application and web portal. - [CQT Fernox App Guide](https://help.fernox.app/en/articles/122-cqt-fernox-app-guide): After downloading the app and completing registration, you can create a new Commercial Water Quality Water Test by following the steps below or watching the video guide. ## Postal Water Tests > Commercial Fill Water Test - [CFT Testing Parameters](https://help.fernox.app/en/articles/119-cft-testing-parameters): Measures 4 key water quality parameters to provide an overview of the fill water and help determine its suitability for use in commercial heating systems. - [CFT Contents & Preparation](https://help.fernox.app/en/articles/115-cft-contents-and-preparation): The Commercial Fill Water Test is a paperless, smart phone driven, postal laboratory service designed for commissioning monitoring, and maintaining commercial heating systems. Once the sample has completed laboratory testing, the system will generate a PDF certificate which will be automatically sent to the user that submitted the sample in the mobile application. All the submissions will be stored in your account, so you can access them whenever you want from the mobile application and web portal. - [CFT Fernox App Guide](https://help.fernox.app/en/articles/120-cft-fernox-app-guide): After downloading the app and completing registration, you can create a new Commercial Fill Water Test by following the steps below or watching the video guide. ## Postal Water Tests > Chemical Parameters - [What is Appearance?](https://help.fernox.app/en/articles/180-what-is-appearance): Appearance is a visual assessment of the colour and clarity of the system water. Water should generally be clear or only slightly coloured by treatment products; cloudy, brown, red or black water can indicate corrosion products, sludge, debris or other contamination within the heating system. - [What is pH?](https://help.fernox.app/en/articles/179-what-is-ph): pH measures how acidic or alkaline the heating system water is. Maintaining the correct pH is essential because water that is too acidic or too alkaline can accelerate corrosion, affect inhibitor performance and contribute to scale or deposits. The appropriate range depends on the system materials, treatment used and applicable manufacturer guidance. - [What is Conductivity uS/cm?](https://help.fernox.app/en/articles/147-what-is-conductivity-uscm): Conductivity measures the level of dissolved electrically charged substances, such as salts, minerals and treatment chemicals, within the system water. Abnormal or changing conductivity can indicate contamination, excessive dissolved solids or changes in water chemistry that could contribute to corrosion or other system problems. - [What is M-Alkalinity As CaCo3 mg/L?](https://help.fernox.app/en/articles/148-what-is-m-alkalinity-as-caco3-mgl): M-Alkalinity measures the ability of the system water to resist changes in pH, primarily due to bicarbonates and carbonates present in the water. Abnormally high or low alkalinity can affect water chemistry stability and may increase the risk of corrosion or scale formation when combined with other system conditions. - [What is Calcium mg/L?](https://help.fernox.app/en/articles/149-what-is-calcium-mgl): Calcium is a naturally occurring mineral in water and one of the main contributors to water hardness. High calcium levels can increase the risk of limescale forming on hot surfaces such as boiler heat exchangers, particularly when combined with high alkalinity and suitable pH conditions. - [What is Suspended Solids mg/L?](https://help.fernox.app/en/articles/150-what-is-suspended-solids-mgl): Suspended solids measure the amount of undissolved particles, such as rust, corrosion debris, sludge and dirt, circulating within the system water. High levels can indicate a dirty or corroding system and may contribute to blockages, reduced circulation, component wear and poor heating performance. - [What is P-Alkalinity as CaC03 mg/L?](https://help.fernox.app/en/articles/151-what-is-p-alkalinity-as-cac03-mgl): P-Alkalinity measures the portion of the water’s alkalinity associated mainly with carbonate and hydroxide ions. When compared with total M-Alkalinity and pH, it helps identify the balance of alkaline substances within the system and can indicate conditions that may contribute to scale formation or unsuitable water chemistry. - [What is Total Hardness As CaCo3 mg/L?](https://help.fernox.app/en/articles/152-what-is-total-hardness-as-caco3-mgl): Total Hardness measures the amount of hardness-forming minerals, mainly calcium and magnesium, dissolved in the system water. High hardness can increase the risk of limescale and other deposits forming on hot surfaces, reducing heat-transfer efficiency and potentially affecting system performance and component life. - [What is Odour?](https://help.fernox.app/en/articles/181-what-is-odour): Odour is an assessment of any unusual smell from the system water. Strong or unexpected odours can indicate chemical contamination or microbiological activity; for example, a rotten egg smell may be associated with hydrogen sulphide produced by sulphate-reducing bacteria. Odour should always be considered alongside other chemical and microbiological test results. - [What is Hardness Deposition %?](https://help.fernox.app/en/articles/153-what-is-hardness-deposition-percent): Hardness Deposition % indicates the extent to which hardness-forming minerals may have deposited from the system water as limescale. High levels can suggest scale formation on components such as heat exchangers, which can reduce heat transfer, restrict flow, increase boiler noise and reduce system efficiency. - [What is Magnesium mg/L?](https://help.fernox.app/en/articles/154-what-is-magnesium-mgl): Magnesium is a naturally occurring mineral that contributes to water hardness. Higher levels can increase the overall potential for mineral deposits and scale formation, particularly when combined with calcium, alkalinity and high system temperatures. - [What is Chloride mg/L?](https://help.fernox.app/en/articles/155-what-is-chloride-mgl): Chloride is a dissolved salt naturally present in water. High concentrations can make system water more corrosive and may increase the risk of localised pitting corrosion, particularly in susceptible metals such as stainless steel and aluminium. - [What is Excess Chloride mg/L?](https://help.fernox.app/en/articles/156-what-is-excess-chloride-mgl): Excess Chloride measures how much additional chloride is present in the heating system compared with the original or reference filling water. Elevated levels can indicate contamination or changes in the system water and may increase the risk of localised corrosion and damage to susceptible system components. - [What is Lithium mg/L?](https://help.fernox.app/en/articles/157-what-is-lithium-mgl): Lithium measures the amount of dissolved lithium present in the system water. It is primarily an informational and diagnostic parameter that can help identify changes in water chemistry, chemical treatment or contamination when compared with the original filling water and previous test results. - [What is Sodium mg/L?](https://help.fernox.app/en/articles/158-what-is-sodium-mgl): Sodium measures the amount of dissolved sodium present in the system water. Levels can be influenced by the original water supply, water softening and chemical treatment, so the result is useful for understanding how the system has been filled and treated and identifying unexpected changes in water chemistry. - [What is Potassium mg/L?](https://help.fernox.app/en/articles/159-what-is-potassium-mgl): Potassium measures the amount of dissolved potassium present in the system water. It may originate from the filling water or chemical treatments, and elevated levels can indicate changes in the system's water chemistry or possible contamination. The result is most useful when considered alongside conductivity, alkalinity, chloride and other treatment-related parameters. - [What is Molybdate mg/L?](https://help.fernox.app/en/articles/160-what-is-molybdate-mgl): Molybdate is commonly used as an indicator of molybdate-based corrosion inhibitor within heating-system water. Testing its concentration helps determine whether sufficient inhibitor is present to protect boilers, radiators, pipework and other system components against internal corrosion. - [What is Silicates mg/L?](https://help.fernox.app/en/articles/161-what-is-silicates-mgl): Silicates are naturally occurring mineral compounds that may also be present in some heating-system treatment chemicals. At appropriate levels they can contribute to corrosion protection, while unusually high or unstable levels may indicate over-treatment, contamination or a risk of deposit formation within the system. - [What is Aluminium mg/L?](https://help.fernox.app/en/articles/162-what-is-aluminium-mgl): Aluminium measures the amount of aluminium present in the system water. Elevated levels can indicate corrosion of aluminium-containing components such as heat exchangers or radiators, particularly where pH or corrosion protection is unsuitable. The result should be considered alongside pH, inhibitor levels and other corrosion indicators. - [What is Dissolved Iron mg/L?](https://help.fernox.app/en/articles/163-what-is-dissolved-iron-mgl): Dissolved Iron measures the amount of iron chemically dissolved in the system water. Elevated levels can indicate active corrosion of steel or iron-containing components and may be an early warning of sludge formation, reduced system efficiency and potential component damage. - [What is Iron mg/L?](https://help.fernox.app/en/articles/164-what-is-iron-mgl): Iron measures the amount of iron present in the system water, including corrosion products released from steel and other ferrous components. Elevated levels can indicate corrosion or the presence of rust, magnetite and sludge, which may lead to blockages, reduced circulation, poor heating performance and component damage. - [What is Dissolved Copper mg/L?](https://help.fernox.app/en/articles/165-what-is-dissolved-copper-mgl): Dissolved Copper measures the amount of copper chemically dissolved in the system water. Elevated levels can indicate active corrosion of copper pipework, heat exchangers or fittings and may provide an early warning of unsuitable water chemistry or inadequate corrosion protection. - [What is Copper mg/L?](https://help.fernox.app/en/articles/166-what-is-copper-mgl): Copper measures the amount of copper present in the system water, including copper released from pipework, heat exchangers and fittings. Elevated levels can indicate corrosion or existing copper-containing debris and may help identify conditions that could lead to leaks, deposits or premature component damage. - [What is Total Zinc mg/L](https://help.fernox.app/en/articles/167-what-is-total-zinc-mgl): Total Zinc measures the amount of zinc present in the system water, including dissolved zinc and zinc-containing particles. Elevated levels can indicate corrosion of brass, galvanised or other zinc-containing components and may help identify material deterioration or unsuitable system-water chemistry. - [What is Phosphorus mg/L?](https://help.fernox.app/en/articles/168-what-is-phosphorus-mgl): Phosphorus measures the amount of phosphorus-containing compounds present in the system water. It may originate from filling water or chemical treatments such as phosphate-based inhibitors, and testing it can help identify treatment levels, contamination or conditions that may contribute to deposit formation. - [What is Boron mg/L?](https://help.fernox.app/en/articles/169-what-is-boron-mgl): Boron measures the amount of boron-containing substances present in the system water. Levels can be influenced by the filling water and certain treatment chemicals, so the result is mainly used to understand the system's treatment chemistry and identify unexpected changes or dilution. The appropriate level depends on the treatment used. - [What is Molybdenum mg/L?](https://help.fernox.app/en/articles/170-what-is-molybdenum-mgl): Molybdenum is commonly used as an indicator of molybdate-based corrosion treatment within heating-system water. Testing it can help determine whether the expected inhibitor is present and identify possible under-dosing, dilution or changes in the system's treatment chemistry. The appropriate level depends on the treatment being used. - [What is Sebacate mg/L?](https://help.fernox.app/en/articles/171-what-is-sebacate-mgl): Sebacate is an organic compound used in some corrosion-inhibitor formulations. Measuring its concentration can help confirm that the expected treatment is present and identify possible dilution, under-dosing or changes in the system's treatment chemistry. The appropriate level depends on the inhibitor being used. - [What is Nitrate mg/L?](https://help.fernox.app/en/articles/172-what-is-nitrate-mgl): Nitrate is a dissolved compound that may naturally be present in filling water. It is mainly used as an informational parameter to help characterise the system water and identify unexpected changes in water source, contamination or treatment chemistry when compared with the original filling water. - [What is Nitrite mg/L?](https://help.fernox.app/en/articles/173-what-is-nitrite-mgl): Nitrite is a dissolved nitrogen compound that may originate from the filling water, certain treatment chemicals or changes within the system water. Testing it helps identify treatment chemistry and unexpected changes or contamination, and the result is most useful when considered alongside nitrate and other water-quality parameters. - [What is Sulphates mg/L?](https://help.fernox.app/en/articles/174-what-is-sulphates-mgl): Sulphates are dissolved salts that may naturally occur in filling water. Testing them helps characterise the system water and identify unexpected changes, contamination or conditions that may contribute to deposits or microbiologically influenced corrosion. The result is mainly used as an informational parameter alongside other water-quality measurements. - [What is Refractive Index?](https://help.fernox.app/en/articles/175-what-is-refractive-index): Refractive Index measures how light bends as it passes through the system fluid. In systems containing glycol or antifreeze, it can be used to determine the fluid concentration and confirm whether the system has the expected level of frost protection. The correct result depends on the type of heat-transfer fluid and its required concentration. - [What is Monoethylene Glycol %?](https://help.fernox.app/en/articles/176-what-is-monoethylene-glycol-percent): Monoethylene Glycol is an antifreeze ingredient used in some heating and heat-pump systems. Testing its concentration helps confirm that the system has sufficient frost protection and can identify dilution, incorrect dosing or loss of heat-transfer fluid. The correct percentage depends on the product used and the required frost-protection temperature. - [What is Monopropylene Glycol %?](https://help.fernox.app/en/articles/177-what-is-monopropylene-glycol-percent): Monopropylene Glycol is an antifreeze ingredient used in many heating and heat-pump systems. Testing its concentration helps confirm that the system has sufficient frost protection and can identify dilution, incorrect dosing or loss of heat-transfer fluid. The correct percentage depends on the product being used and the required frost-protection temperature. - [What is Amonia mg/L?](https://help.fernox.app/en/articles/178-what-is-amonia-mgl): Ammonia is a nitrogen-containing substance that can indicate changes in system water chemistry or microbiological activity. Elevated levels may result from the breakdown of nitrite- or nitrate-based treatments and can increase the risk of corrosion of copper and brass components. The result should be considered alongside nitrite, nitrate, copper and microbiological indicators. - [What is Microbiological TVC?](https://help.fernox.app/en/articles/182-what-is-microbiological-tvc): Microbiological TVC measures the overall level of viable bacteria capable of growing from a sample of the system water. Elevated levels can indicate microbiological contamination or biofilm growth, which may contribute to corrosion, deposits, restricted flow and reduced system performance. The result should be interpreted using the laboratory's specified test method and alongside other microbiological and water-quality parameters. - [What is Total Dissolved Solids Calculated (mg/L)?](https://help.fernox.app/en/articles/185-what-is-total-dissolved-solids-calculated-mgl): Total Dissolved Solids (TDS) estimates the overall amount of dissolved salts, minerals and treatment chemicals present in the system water. It is calculated from conductivity and can help identify inadequate flushing, contamination or changes in water chemistry. The result should be compared with the filling water and known system treatment rather than assessed on its own. ## Postal Water Tests > FAQ > General Information - [Can I submit multiple samples at once?](https://help.fernox.app/en/articles/22-can-i-submit-multiple-samples-at-once): Yes, but ensure each pair of samples and their corresponding Order Form are in separate envelopes. - [Do I need to submit my postal test on the Fernox App?](https://help.fernox.app/en/articles/10-do-i-need-to-submit-my-postal-test-on-the-fernox-app): Postal test kits require app submission for tracking and processing, except the System Health Check, which is fully paper-based. - [What should I do if my sample bottle leaks during transit?](https://help.fernox.app/en/articles/17-what-should-i-do-if-my-sample-bottle-leaks-during-transit): Sample Posting - [Do I need to submit my System Health Check on the Fernox App?](https://help.fernox.app/en/articles/11-do-i-need-to-submit-my-system-health-check-on-the-fernox-app): The System Health Check is fully paper-based and doesn’t require app submission; results are emailed and can also be accessed in the Fernox App. - [Where can I find the System Health Check Portal?](https://help.fernox.app/en/articles/8-where-can-i-find-the-system-health-check-portal): System Health Check is now paper-based; online submission is not available. - [Can I access my test results at any time?](https://help.fernox.app/en/articles/25-can-i-access-my-test-results-at-any-time): Test Results Access - [When will my results be ready?](https://help.fernox.app/en/articles/44-when-will-my-results-be-ready): Receive Results via Email and in the App - [What should I do if I haven't received my results?](https://help.fernox.app/en/articles/45-what-should-i-do-if-i-haven-t-received-my-results): Check Status and Contact Support if Results Are Delayed - [How can I keep a record of the pass / fail for each job?](https://help.fernox.app/en/articles/85-how-can-i-keep-a-record-of-the-pass-fail-for-each-job): It is very easy to keep track of test results with the free to download Fernox App, which installers can use to manage and evidence each test. Using the in-app camera, users take a picture of the test strip and select its colour to generate the pass or fail result. Using this process will auto-generate a PDF certificate with the result to your email address and this acts as evidence that the test has been completed and the system is fully protected. For ease, all of your submissions will be stored in your account for you to view and export on demand. If a test fails, installers can also demonstrate that action has been taken and the system subsequently re-tested to receive a positive result. - [What do the Sample Statuses mean?](https://help.fernox.app/en/articles/184-what-do-the-sample-statuses-mean): The status of a water test indicates the current stage of the sample, from submission through to the laboratory result. ## Postal Water Tests > FAQ > Testing Samples - [Is it mandatory to fill in all the fields during test setup?](https://help.fernox.app/en/articles/90-is-it-mandatory-to-fill-in-all-the-fields-during-test-setup): All fields marked with an asterisk (*) are required to complete the test setup. These include customer reference, address, system type, and others. - [Changing Submitted Samples Address](https://help.fernox.app/en/articles/183-changing-submitted-samples-address): Did you notice a mistake in a submitted sample test? ## Postal Water Tests > FAQ > Understanding Results - [What do I receive after completing the System Health Check?](https://help.fernox.app/en/articles/19-what-do-i-receive-after-completing-the-system-health-check): Sample Results - [What if my results indicate an unexpected issue?](https://help.fernox.app/en/articles/46-what-if-my-results-indicate-an-unexpected-issue): Follow Recommendations or Seek Professional Advice - [What does the PDF certificate include?](https://help.fernox.app/en/articles/93-what-does-the-pdf-certificate-include): The PDF certificate includes details of the test submission, the test results, as well as a recommendation and conclusion based on the results. ## Postal Water Tests > FAQ > Advice - [What should heating system water look like?](https://help.fernox.app/en/articles/106-what-should-heating-system-water-look-like): The appearance of the water inside a heating system can give insights into the system’s health and whether it is functioning properly. Ideally, the water should meet these characteristics: ## User Guides > Getting Started - [Downloading the Fernox App](https://help.fernox.app/en/articles/5-downloading-the-fernox-app): Get started by downloading the Fernox App to access smart water testing tools and features. - [Creating an account](https://help.fernox.app/en/articles/3-creating-an-account): Quickly create your account and start using the Fernox App in just a few simple steps. - [Log in to your account](https://help.fernox.app/en/articles/4-log-in-to-your-account): Creating an account is a quick, one-time process that ensures you can access and use the app without hassle. Once your account is registered, you can log in anytime using your credentials to submit samples for water testing, view all your PDF reports, and manage your submissions effortlessly. - [User Roles and Permissions](https://help.fernox.app/en/articles/143-user-roles-and-permissions): Fernox features three platform roles—User, Manager, and Organisation Manager—each with specific permissions for submitting water tests and tracking data. ## User Guides > Getting Started > FAQ - [Is the Fernox App free or paid?](https://help.fernox.app/en/articles/131-is-the-fernox-app-free-or-paid): The Fernox App is free to download and use. - [Can I access my test results at any time?](https://help.fernox.app/en/articles/26-can-i-access-my-test-results-at-any-time): Yes, once a test is completed, all submissions are stored in your account, and you can access them whenever you need. - [What information is required to register?](https://help.fernox.app/en/articles/50-what-information-is-required-to-register): Requirements for App Registration - [Can I use social media to sign up?](https://help.fernox.app/en/articles/51-can-i-use-social-media-to-sign-up): Sign-Up Only Available via Email - [Does the application support SSO?](https://help.fernox.app/en/articles/52-does-the-application-support-sso): Single Sign-On (SSO) Supported for Corporate Logins ## User Guides > Using the App - [Submitting Your First Test](https://help.fernox.app/en/articles/137-submitting-your-first-test): The Fernox Water Test App makes it quick and easy to submit a water sample for analysis. Follow the steps below to complete your first test submission. - [Draft Submissions](https://help.fernox.app/en/articles/139-draft-submissions): Take tests anywhere and save your responses as drafts — submit them whenever you’re ready, whether you want to pause or complete it later. - [Offline Mode](https://help.fernox.app/en/articles/82-offline-mode): No connection? No problem. You can still take tests offline — your responses will be saved on your device and ready to submit once you’re back online. - [Invite a Manager](https://help.fernox.app/en/articles/138-invite-a-manager): As a registered user of the Fernox App or web portal, you can invite a Manager to view your submitted samples. This is helpful if you want to share test results with someone responsible for managing your site, installation, or service. - [System Sizing Calculator](https://help.fernox.app/en/articles/146-system-sizing-calculator): The System Size Calculator helps you quickly estimate the water volume of a heating system, making it easier to determine the correct dosage of Fernox cleaning, protection, and maintenance products. ## User Guides > Account Management - [Updating account information](https://help.fernox.app/en/articles/30-updating-account-information): Updating Your Account Information - [Changing email address](https://help.fernox.app/en/articles/28-changing-email-address): Updating Your Email Address - [Password resetting](https://help.fernox.app/en/articles/7-password-resetting): This section provides a step-by-step guide on how to reset your password if you can’t remember it. Follow the instructions below to regain access to your account quickly and securely. - [Account Deletion](https://help.fernox.app/en/articles/29-account-deletion): Deleting Your Fernox App Account - [Notification Settings](https://help.fernox.app/en/articles/31-notification-settings): Managing Notifications and Email Reports - [Biometrics login](https://help.fernox.app/en/articles/32-biometrics-login): Logging in with Biometrics or PIN makes accessing your account faster and more secure. Once set up, you can use your fingerprint, face recognition, or a 4-digit PIN to log in quickly—no need to enter your full credentials each time. This feature helps you access water test reports, manage submissions, and use the app seamlessly while keeping your data protected. ## User Guides > Account Management > FAQ - [How can I log out of the app?](https://help.fernox.app/en/articles/27-how-can-i-log-out-of-the-app): Account Management - [Can I be logged in to multiple devices at the same time?](https://help.fernox.app/en/articles/53-can-i-be-logged-in-to-multiple-devices-at-the-same-time): Single Device Login Only - [Does the app work offline?](https://help.fernox.app/en/articles/83-does-the-app-work-offline): While the app does not function fully offline, it includes a feature that lets you save your sample submission. If you experience a loss of signal, you can save your work and submit the sample as soon as you’re back online—ensuring you don’t lose progress or time. ## Manager Guides > Getting Started - [Apply for Manager Access](https://help.fernox.app/en/articles/133-apply-for-manager-access): At this time, Managers can only access data from other users through the web portal, available at https://fernox.app. All users—whether new or existing, using the Fernox App, the web portal, or migrating from our older Water Test Apps—must self-register. If a Manager does not plan to submit water samples themselves, they can simply register via the web portal and do not need to download or use the Fernox App. ## Manager Guides > Using the Portal - [Test Sample Data](https://help.fernox.app/en/articles/135-test-sample-data): Currently, managers can only access data from other users via the web portal at https://fernox.app. Once granted manager-level access permissions, you will be able to view user samples from all individuals who are linked to you — either automatically (for organisational managers) or manually (for regular managers). In either case, the process for accessing managed engineers’ data is the same for both manager types. - [Exporting Test Sample Data](https://help.fernox.app/en/articles/136-exporting-test-sample-data): Quickly generate customised sample reports by filtering, selecting fields, and exporting in your preferred format from the Fernox portal. ## Manager Guides > Account Management - [Email Notifications](https://help.fernox.app/en/articles/134-email-notifications): Manage the report emails from your engineers or installers that are sent to your inbox. As a manager, you can enable or disable these emails individually, giving you full control over which notifications you receive based on your preferences. ## Security Learn how Fernox protects your data, including our privacy practices, security measures, compliance standards, and certifications. - [Fernox registered Data Protection Officer (DPO)](https://help.fernox.app/en/articles/54-fernox-registered-data-protection-officer-dpo): Data Protection and GDPR Compliance at Fernox - [Information Commissioner’s Office (ICO)](https://help.fernox.app/en/articles/55-information-commissioner-s-office-ico): Fernox ICO Registration and Compliance - [ISO27001 Certification](https://help.fernox.app/en/articles/61-iso27001-certification): Fernox Certification and Information Security ## Security > FAQ - [Who has access to my water test results?](https://help.fernox.app/en/articles/56-who-has-access-to-my-water-test-results): Privacy of Your Water Test Results - [How do I report a privacy concern?](https://help.fernox.app/en/articles/57-how-do-i-report-a-privacy-concern): Contact us incase of privacy concerns - [How do you use my data?](https://help.fernox.app/en/articles/58-how-do-you-use-my-data): How Fernox Uses Your Data - [What data does the app collect?](https://help.fernox.app/en/articles/59-what-data-does-the-app-collect): Types of Data Collected by Fernox - [How is my personal information protected?](https://help.fernox.app/en/articles/60-how-is-my-personal-information-protected): Secure Storage and Encryption of Personal Data - [What does ISO certification mean for me as a user?](https://help.fernox.app/en/articles/62-what-does-iso-certification-mean-for-me-as-a-user): How ISO Certification Protects Your Data - [How often is Fernox’s ISO certification reviewed?](https://help.fernox.app/en/articles/63-how-often-is-fernox-s-iso-certification-reviewed): Maintaining Continuous Security Compliance ## Troubleshooting & Support Find solutions to common issues, troubleshooting guides, and support resources to help you resolve problems with the Fernox App, your water tests, or your account. - [Contact Us](https://help.fernox.app/en/articles/130-contact-us): If you can’t find the answers you need, reach out to us. We’re here to assist you promptly. ## Troubleshooting & Support > Account Troubleshooting - [Login Troubleshooting](https://help.fernox.app/en/articles/140-login-troubleshooting): If you're having trouble logging in, try the steps below. - [Submitting samples on the Fernox web portal](https://help.fernox.app/en/articles/39-submitting-samples-on-the-fernox-web-portal): Samples Can Only Be Submitted via the App - [PDF certificate not received via email](https://help.fernox.app/en/articles/42-pdf-certificate-not-received-via-email): Verify Email and Check Spam Folder - [One Time Password(OTP) Troubleshooting](https://help.fernox.app/en/articles/141-one-time-passwordotp-troubleshooting): A One-Time Password (OTP) is a temporary verification code sent to a user's registered email address, mobile phone, or authentication app to confirm their identity. If you are not receiving an OTP or experiencing any other issues related to it, follow the steps below. ## Troubleshooting & Support > Device Troubleshooting - [Fernox App does not show up in my App Store](https://help.fernox.app/en/articles/37-fernox-app-does-not-show-up-in-my-app-store): We are working hard to launch the Fernox App - [Tablet compatibility](https://help.fernox.app/en/articles/40-tablet-compatibility): Fernox App Works on Smartphones and Some Tablets - [Issues downloading the Fernox App](https://help.fernox.app/en/articles/36-issues-downloading-the-fernox-app): Ensure Your Device Meets App Requirements - [Enabling location access](https://help.fernox.app/en/articles/23-enabling-location-access): Enable Location Access for the Fernox App - [Enabling camera access](https://help.fernox.app/en/articles/24-enabling-camera-access): Enable Camera Access for the Fernox App ## Troubleshooting & Support > App Troubleshooting - [My app is not working](https://help.fernox.app/en/articles/33-my-app-is-not-working): Quick Fixes Before Contacting App Support - [Steps to Take If the App Crashes During Testing](https://help.fernox.app/en/articles/41-steps-to-take-if-the-app-crashes-during-testing): Restart the App or Contact Support if Needed - [Issues with scanning the bottle QR Code](https://help.fernox.app/en/articles/48-issues-with-scanning-the-bottle-qr-code): Scanning QR Codes in the Fernox App - [Issues with scanning Heat Appliance Serial Number](https://help.fernox.app/en/articles/49-issues-with-scanning-heat-appliance-serial-number): Scanning or Entering Heat Appliance Serial Numbers - [How can I submit my usage logs?](https://help.fernox.app/en/articles/145-how-can-i-submit-my-usage-logs): If you've been asked by the Fernox Support team to upload your app logs, you can do so directly from within the Fernox App. These logs help us investigate technical issues by providing diagnostic information about how the app is performing on your device. ## Troubleshooting & Support > Test Results Troubleshooting - [Postal Test Submission Trobleshooting](https://help.fernox.app/en/articles/142-postal-test-submission-trobleshooting): If you've completed a System Health Check, Diagnostic Water Test, Water Quality Test, or any of our Commercial Water Tests and think there may be an issue, read the article below for troubleshooting guidance and possible solutions. ## Optional - [Centro de Ayuda (es)](https://help.fernox.app/es/llms.txt) - [Hilfezentrum (de)](https://help.fernox.app/de/llms.txt)