Vaillant Gas boiler fault S.62
Adjust CO2
Gas boilerWhat it means
Set the CO2 content.
Likely causes
- Incorrect gas group used for the product
- Faulty gas valve assembly, Venturi, or fan requiring replacement
- Defective gas valve assembly
- Defective Venturi
- Defective fan
- CO2 content outside set values requiring air ratio adjustment
- Incorrect gas group for installation requirement
Where to start
- Measure and adjust CO2 content during combustion setup
- Check gas groups specified on the data plate
- Compare supplied gas to data plate specification
The full answer, free
- 34 more checks in order
- How to put it right, step by step
- The manual page for this fault (page 59), right under the answer
Safety: Isolate gas and power before you open the case. If you have been into the gas side, do a tightness test, and a combustion and flue check before you hand back. Gas Safe (UK) or RGI (Ireland) work only.
From the Vaillant manual for the Gas boiler. Check the model on the data plate before you order parts.
Other Vaillant Gas boiler fault codes
- F.00Flow temperature sensor interruption
- F.01Return temperature sensor interruption
- F.03Cylinder temperature sensor interruption
- F.10Flow temperature sensor short circuit
- F.11Return temperature sensor short circuit
- F.13Cylinder temperature sensor short circuit
- F.22Safety shutdown: water deficiency
- F.23Safety shutdown: temperature spread too great
- F.24Safety shutdown: temperature rise too fast
- F.25Safety shutdown: flue gas temperature too high
- F.27Safety shutdown: flame simulation
- F.32Fan fault
- F.33Air pressure switch fault
- F.64Fault: electronics/NTC
- F.65Electronics temperature fault
- F.72Flow and/or return temperature sensor fault
- F.74Water pressure sensor signal outside correct range (too high)
- F.75Pump fault/water deficiency
- F.77Accessory fault (flue non-return flap, condensate pump, etc.)
- F.83Flow and/or return temperature sensor temperature change fault
- F.84Temperature difference fault at the flow and return temperature sensors
- F.85Flow and return temperature sensors installed incorrectly (inverted)
- P.02Minimum load check programme
- S.42Flue non-return flap closed