Choose your Vaillant appliance
About Vaillant
Vaillant is a German heating company founded in Remscheid in 1874, and one of the most common gas boiler brands in the UK and Ireland. Its ecoTEC boilers show faults as an F code on the display, such as F.28 or F.022 on newer models, and many of them can be cleared with the reset button once the cause is fixed.
Vaillant boiler error codes
- F.22Water pressure in the heating system is too low
- F.28Boiler failed to light
- F.29Flame went out and the boiler couldn't relight
- F.20Overheat safety cut-out has tripped
- F.23Too big a gap between flow and return temperature
- F.24Temperature rising too fast
- F.25Flue gas temperature too high
- F.27Flame detected with the burner off
Before you start
- Find your model number. It's on the rating label, usually inside the door or lid, on the frame, or on the back or side panel.
- Try a reset. Unplug the appliance or switch off its breaker for 10 minutes. Many codes are one-off glitches.
- Stay safe. Never bypass safety switches or work on live wiring, gas or refrigerant lines. Each guide tells you when to call a technician.