Boiler Faults in Extreme Cold Temperatures

During extreme cold weather the condense pipe to your boiler can begin to freeze inside. This ice builds up within the pipe eventually resulting in a blockage. In most cases this then results in the boiler not working.


Specific error codes that may be displayed on the boiler screen will indicate this issue and the error codes may be one of the below depending on the make of boiler you have.

Fault Codes:

Baxi – E133 or E28
Ideal Boilers – L2, LF or F2
Glow-Worm – F28 or F29
Potterton – E133 or E28. Or, the error code may alternate between E1 and E33
Worcester Bosch – EA229 or D5
Vaillant – F28 or F29
Viessmann – F4

You may be able to get this resolved quickly by thawing the pipe where safe to do so by following the below process.

  1. Locate the Blockage
    • The pipe is likely to be frozen at its most exposed point, so check the open ends, or any bends in the pipe. Run your hand over the pipe until you feel a section which is colder than the rest, this is likely to be the area which is frozen.
  2. Use hot (but not boiling) water to thaw the pipe
    • Using a jug, kettle or watering can, pour hot water along the length of the pipe. Repeat this until the pipe has thawed. DO NOT use boiling water as it can crack the pipe. If you use a kettle, leave the water to cool for at least 15 minutes after boiling before pouring over the pipe. Alternatively, use a hot water bottle or heat pack to slowly defrost the pipe.
  3. Or use a hot water bottle placed over the coldest feeling part of the pipe.

Once thawed try re-setting the boiler and this should now work, if it does not, please give us a call.