A.O. Smith fault code CO2 value incorrect
Fault code CO2 value incorrect on an A.O. Smith water heater (including BFC) 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.
After a safety alert (gas, flue gas, combustion), reset no more than once and call in a certified gas engineer. If you smell gas, call your national gas emergency number or 112 immediately.
Cause
Fault code CO2 value incorrect on an A.O. Smith water heater indicates: The unit is not set to the correct gas type.
Fixing fault code CO2 value incorrect: step by step
- Note the exact code and the type of your appliance (see the rating plate).
- Check that the appliance has power and that its circuit breaker is on.
- Reset the appliance once. If the code comes straight back, do not keep resetting it.
- If the code comes back, choose the matching part below or have a qualified heating engineer take a look.
Applies to
A.O. Smith BFC, 100, 120, 28, 30, 50, 60, 80.
Fault code CO2 value incorrect on other A.O. Smith series
The same code does not mean the same thing on every series. Check the rating plate to see which series you have:
- CO2 value incorrect on BFC, 100, 120, 28, 30, 50: Fouled venturi.
- CO2 value incorrect on BFC, 100, 120, 28, 30, 50: Leak between the venturi and the flexible venturi connection.
- CO2 value incorrect on BFC, 100, 120, 28, 30, 50: Recirculation of flue gases.
Matching parts
A.O. Smith parts are available from Instalpunt; shipping to EU countries from €12.95 (€16.95 for more distant countries), usually 3–5 working days.
This message does not point directly to one faulty part. If the code keeps coming back, view the A.O. Smith parts:
Fix it yourself or call an engineer?
Always consult the manual for your appliance and work safely. If in doubt or if the fault comes back, call in a qualified professional. A question about a part? Write to us at info@instalpunt.nl.
Frequently asked questions
What does A.O. Smith water heater fault code CO2 value incorrect mean?
The unit is not set to the correct gas type.
How do I fix fault code CO2 value incorrect on an A.O. Smith water heater?
First check the cause described above. Then restart the appliance using the reset button. If the message comes back, a part usually needs replacing or the fault needs to be repaired by a qualified professional.
Which parts do I need for A.O. Smith fault code CO2 value incorrect?
That depends on the exact cause. In the A.O. Smith parts overview at Instalpunt you will find the current price and stock for each part.
Can I fix fault code CO2 value incorrect myself?
You can reset the appliance and check things like the water pressure or settings yourself. Work on gas-carrying parts must be left to a certified gas engineer.
All A.O. Smith water heater faults and codes at a glance →