Vaillant F.23: what it means and when to call a pro · United States
Severity: Stop and call a proVaillant gas boiler error F.23. The temperature difference between flow and return is too large, usually because water is not circulating well.
Smell gas? Leave the building and call the gas emergency number: 911
Meaning
The temperature difference between flow and return is too large, usually because water is not circulating well.
Severity
Stop and call a pro
Stop. Switch it off and call a pro
Steps are not shown for this code because no qualified person has reviewed them yet. What is safe: switch it off, follow the Do not list and call a pro.
Source
Installation and maintenance instructions ecoTEC pro VUW ..6/5-3, Vaillant
The repair: Boiler pump and circulation repair
Prices for repairs in United States are in USD.
Other Vaillant codes
- Vaillant F.24 The boiler temperature is rising too fast, usually because water is not circulating well (air, closed valves or a pump problem).
- Vaillant F.25 The flue gas temperature is too high, or the flue or air supply is faulty or blocked.
- Vaillant F.28 The boiler failed to ignite (no flame was detected) and has locked out.
- Vaillant F.29 The flame went out during operation, or the flame sensor signal is faulty.
- Vaillant F.32 The fan is faulty or is not reaching the correct speed.
Brands in our catalog for gas boiler: Ariston, Baxi, Bosch, Ferroli, Ideal, Potterton, Vaillant, Viessmann, Worcester Bosch. The same code on another brand is not in the catalog yet, and we do not guess what it means.