A.O. Smith fault code The CO2 value (at full load) is incorrect
Fault code The CO2 value (at full load) is incorrect on an A.O. Smith water heater (including Innovo) means: The unit is not set to the correct gas type. Reset the appliance once. If the code comes back, a part is usually faulty. You can check the water pressure and settings yourself; leave work on gas-carrying parts to a certified gas engineer.
Gas, flue or flame fault? One reset is the limit; after that it is a job for a registered gas engineer. Smell gas: no switches or flames, open the windows, get out and ring your national gas emergency number or 112 from outside.
Cause
Fault code The CO2 value (at full load) is incorrect on an A.O. Smith water heater indicates: The unit is not set to the correct gas type.
Fault code The CO2 value (at full load) is incorrect: what to check before you call an engineer
- Write down the exact code and the full model designation from the rating plate; that is what we and any engineer will ask for first.
- Check that the appliance has power and that its circuit breaker has not tripped.
- Press reset once and give the appliance a minute. If the code returns straight away, stop there: repeated resets hide a real fault and can lock the appliance out.
- If the code comes back, pick the matching spare part below, or have a qualified heating engineer diagnose it first.
Applies to
A.O. Smith Innovo, IR 12-160, IR 12-200, IR 20-160, IR 20-200, IR 24-245, IR 24-285, IR 32-245, IR 32-285.
Fault code The CO2 value (at full load) is incorrect on other A.O. Smith series
Careful: on another series this code can mean something else. Your rating plate tells you which line applies:
- The CO2 value (at full load) is incorrect on Innovo, IR 12-160, IR 12-200, IR 20-160, IR 20-200, IR 24-245: Fouled venturi.
- The CO2 value (at full load) is incorrect on Innovo, IR 12-160, IR 12-200, IR 20-160, IR 20-200, IR 24-245: Leak between the venturi and the flexible venturi connection.
- The CO2 value (at full load) is incorrect on Innovo, IR 12-160, IR 12-200, IR 20-160, IR 20-200, IR 24-245: Recirculation of flue gases.
Matching parts
A.O. Smith parts are available from Instalpunt; shipping €9.95 to Austria, Denmark, Italy, Spain and Sweden and €12.95 to the other EU countries, free from €199, usually 3–5 working days.
No single part is behind this code. These are the parts that most often fit this appliance:
A.O. Smith ionisation pin after September 2009 € 47.08
A.O. Smith glow plug for e.g. Innovo IR32-380L 0311990(S) € 95.28- A.O. Smith fan adapter € 116.70
DIY or engineer: where the line is
Keep the manual at hand, switch off the power before you open a cover and stop at the sealed combustion section. Not sure which part you need? E-mail a photo of the rating plate to info@instalpunt.nl.
Frequently asked questions
What does A.O. Smith water heater fault code The CO2 value (at full load) is incorrect mean?
The unit is not set to the correct gas type.
How do I fix fault code The CO2 value (at full load) is incorrect on an A.O. Smith water heater?
Work through the step-by-step list above, then reset once. A code that returns after that is rarely solved by resetting again: either a part has failed or the appliance needs a proper diagnosis by a heating engineer.
Which parts do I need for A.O. Smith fault code The CO2 value (at full load) is incorrect?
Only the cause tells you. Open the A.O. Smith parts overview, pick your series from the rating plate and every part is listed with its manufacturer number, price and stock, ready to ship to any EU address.
Can I fix fault code The CO2 value (at full load) is incorrect myself?
The checks in the list above, yes: pressure, power, valves, condensate trap and a single reset. Anything inside the sealed combustion section or on the gas train is for a registered gas engineer, in every EU country.
All A.O. Smith water heater faults and codes at a glance →