32 codes
Boiler error codes
UK boiler codes from Worcester Bosch, Vaillant, Baxi and Ideal, side by side. Low pressure and a frozen condensate pipe are things you can often sort yourself; anything inside the case is a job for a Gas Safe engineer.
Common problems
What it's doing, the code each brand shows for it, and what to check first.
Same fault, every brand
Find the fault you're seeing, then your brand. Each code opens its own page with the checks and a verdict.
| Fault | Worcester Bosch | Vaillant | Baxi | Ideal |
|---|---|---|---|---|
| Low pressureThe water pressure in the heating system is too low or too high. | Worcester Bosch1017A1 | VaillantF22F75 | BaxiE118H.02.07 | IdealF1 |
| Frozen or blocked condensate pipeThe pipe that drains condensed water is frozen or blocked. | Worcester BoschD5 | — | BaxiE119 | — |
| Heating faultIt isn't heating properly. | — | VaillantF23 | — | — |
| Temperature sensorA sensor can't read the temperature. | Worcester BoschE2 | — | — | IdealF4 |
| Ignition or flame failureIt tried to light and couldn't, or lost the flame. | Worcester BoschEA 227 | VaillantF28F29F27F62 | BaxiE133E128 | IdealF2L2L6 |
| OverheatingIt got too hot and cut out. | Worcester BoschE9 | VaillantF20 | BaxiE125E110 | IdealL1FD |
| Fan motorA fan isn't turning. | Worcester BoschC6 | — | BaxiE160 | IdealF3 |
| Control boardThe electronics or their wiring have a fault. | Worcester BoschF0 | — | — | — |