Express Inhibitor test

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The Express Inhibitor Test provides instant confirmation of system status and inhibitor concentration submitted via the Fernox Water Test App.


The Express Inhibitor Test makes on-site testing for sufficient levels of inhibitor quick and simple. The process will auto-generate the outcome PDF certificate to your email address, and all of your submissions will be stored in your account for you to view and export on demand.

  • Quick and simple on-site testing of inhibitor concentration
  • One test strip per system. Each vial contains 50 test strips.
  • Suitable for testing all molybdate-based inhibitors
  • Download Fernox Water Test App for lab-style report certificate
  • Allows compliance with BS 7593:2019 and the Benchmark scheme
  • Allows compliance with boiler warranties

Download on IOS

Download on Google Play

You can also view your samples on


The Express Inhibitor Test provides a rapid on-site analysis of the concentration of all Fernox Protectors, and other molybdate based inhibitors, in central heating system water. Easy and intuitive to use, it is a quick and simple testing method to establish the presence of inhibitor within the system. Testing the concentration of inhibitor allows compliance with BS 7593:2019, the Benchmark scheme, and may be required to comply with boiler warranties. When used in conjunction with the Fernox Water Test App, which is free to download from Apple App Store or Google Play Store, this single usage, on-site heating system test can be saved within the App and a lab-style report certificate available to download . A pass or a fail is confirmed based on the colour of the test strips compared against the colour chart on the vial. In the event of fail result, take corrective action simply add more inhibitor and retest to receive the pass certificate.

Instructions for Use

1. Scan QR code on the test strip vial, download Fernox Water Test App and register

2. Add new sample on the App

3. Fill out system details (address, age of system etc…)

4. Take a sample of system water which is representative of the system as a whole (drain the water for several seconds before taking the sample)

5. Dip the test strip into the system water for 1 second and remove

6. Compare to colour chart within 10 seconds and take a picture

7. Select the colour which most accurately represents the colour observed on the test strip and submit The sample is now saved on the app, the pass/ fail determined and a report is generated and emailed.