Winter Weather Advice: Boiler fault codes and what to do if they occur

What are fault codes

Our boilers are all equipped with specific diagnostics that identify problems in your central heating system through display codes. Fault codes are indicators that signal an error has occurred in your boiler system. The codes help give a simplified understanding of the problem at hand for experts and homeowners.

What are the main boiler fault code letters

Various boiler codes can appear on your system, whether it is on the front of the system or your control, each with a unique identity resembling specific faults. Some codes are the same across all boiler types, but others differ.

F codes are typically the most common and are used to display various issues in your boiler, whether minor or major. The “F” can mean either fault or failure and is the main indication of whether a general issue has occurred in the boiler. However, in our boilers, “F” is also used. “L” or “ABC” codes that would typically flash up on other manufacturers boilers.

F codes can be found in our current range, like the Betacom, but also in some of our older product ranges, including the Xtrafast, Ultracom, Sxi, Hxi, Flexacom and Cxi.

Common boiler fault codes

The easiest fault code that you can personally fix on your boiler is F22 (F9 in older appliances). If the F22 (or F9) code is flashing this usually indicates a fault in the heating system water pressure and can usually be resolved by simply repressurising the system.

Another common fault is F28/F29 (F1 In older appliances), this usually relates to the gas supply (pre-payment meter out of credit), or the condensate pipe could be frozen or blocked. This may mean topping up a gas pre-payment card. Or, thawing out a frozen condensate pipe. After which, the boiler should return to operation when "reset" If either of these faults occur.

If any fault codes appear on your boiler and you are unsure, contact a Glow-worm installer immediately and don't attempt to fix the issue yourself.

What are boiler lock codes?

Locking codes are indicators that flash up in similar fashion to regular fault codes due to the safety mechanism detecting a danger within the system.

However, in most cases, these faults will show on your screen even if you reset the system. We always recommend that you contact your local installer for more information about the fault causing the lock so they can find the quickest and most efficient solution.