Maintaining your Flue Gas Analyser
Tips and tricks on keeping your flue gas analyser optimised.
Flue gas analysers have become an essential tool as part of boiler servicing, but it’s important to make sure you are getting the most our of tour device to avoid errors and ensure trouble free operation. Due to the requirements of gas safety, all manufacturers recommend you have your flue gas analyser serviced annually to ensure it is in proper working condition and fully calibrated/tested.
The electrochemical sensors used in flue gas analysers react with the target gas they are designed to measure (such as O2 or CO), and this reaction causes a change in electrical response that the analyser can then use to determine the gases present.
As these sensors deplete, they will eventually need replacing as they cannot give correct readings, and an analyser that has not been calibrated and serviced for over 12 months may begin to show less accurate results, potentially meaning that any combustion reading taken could be inaccurate. Unregistered gas work and uncalibrated or faulty tools can put the lives of people at risk of carbon monoxide poisoning, fire and explosion.
Fully charge your device - make sure that your analyser has enough battery charge to complete the test, it’s no good to you without a charged battery!
Purge the analyser with fresh air – this should be done before and after every use, for this to be done properly the flue gas probe must be connected during this process.
Wait until the boiler has warmed up - to help prevent you from gathering incorrect readings, make sure the boiler has warmed up before inserting the flue gas probe into the flue. This is because high levels of CO can potentially damage the sensors within an analyser.
Make sure you have the correct analyser for the appliance under test - testo analysers designed for domestic use have sensors capable of measurement up to 4,000 ppm of CO, if you are working on more commercial sized boilers then products such as the testo 300LL allows measurement without damage up to 30,000ppm of CO due to its unique dilution system.
Only have the analyser pump running when taking a reading - the analyser, if left running unobserved, can be subject to high levels of CO on boiler start up and will unnecessarily pull excess condensate into the water trap. This will also needlessly deplete the battery.
Check that the particle filter – it’s important to make sure that the particle filter in the probe is clean and not wet. Replace the filter when oil deposits blacken the whole of the filter and exchange the filter if it is wet. If a filter is wet but is not contaminated it will dry naturally in the analysers carry case, but it always good practice to make sure that you have a clean and dry filter at all times in case you need to make a change.
Store your analyser correctly- it should be kept in a warm, dry place overnight. Condensation can form internally within the sensors, or even on the circuit board which can cause damage to the analyser, and there is the secondary aspect of cold temperature can affect sensor accuracies. For this reason we recommend FGA are not kept in vans overnight.