Why won't my analyser switch off?

Why shouldn't I replace my own sensors?

Why doesn't my CO sensor zero quickly?

Why does the cold affect my readings?

Why do my EFF readings show ----?

Why are my flue temperature readings -ve when in a hot flue?

Where does CO come from?

When do I know that the readings I am seeing are the ones I should record or print?

What values for excess air can be expected?

What should O2 ref be set to?

What is the difference between net combustion efficiency and gross combustion efficiency?

What is the difference between combustion efficiency and boiler efficiency?

What is the difference between combustion Eff and boiler Eff?

What is special about a condensing boiler?

What is Oxygen referencing?

What is net temperature and how do I measure it?

What is excess air?

What is air free CO?

What general care should be taken of gas analysers?

What CO level can I expect from a boiler?

What are the effects of Carbon Monoxide?

What are safe levels of CO and CO2 in rooms?

What are Hydrogen Compensated CO Sensors?

Oxygen Referencing

My analyser is on, probe is in flue but O2 reading is 20.9 and CO reading is zero. What's wrong?