Posted 15th Dec 2022
Our boiler stopped working yesterday morning. It wouldn't restart (it was trying to but would go off again).

Due to these freezing temps, the condensation pipe had frozen.

We established this by tapping the condensation pipe outside the house & could hear it was hollow at the top but sounded dense towards the lower part near ground.

We defrosted it by wrapping old clothing around the frozen area & poured boiling water from kettle about 6-8 times (lost count tbh).
During this process we could hear a crunching noise but that was the defrosting process.

We removed the wet clothing wrapping from pipe once it cooled down & tried restarting boiler & it started up!

Sharing this in case it helps someone out there.

BTW make sure you grit/salt area on ground where hot water would have ran off as it will have iced up.
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  1. Avatar
    Thanks, I'm sure this will help many of us with a similar issue
    Thanks, we were so stressed yesterday morning as Britishgas had given us an engineer visit in 8 days time!

    Britishgas had said due to freezing temps, there was high demand for boiler repairs & that's the earliest they could get to us.

    That got us thinking if its something to do with frozen pipes & got us investigating & eventually managed to sort problem.
  2. Avatar
    Should always insulate/lag the condensate pipe.
    We have now but its kind of after the horse has bolted.
  3. Avatar
    Spooky - this video popped as a recommendation on my YT feed yesterday.
  4. Avatar
    We had the same problem a few years back - boiler is in the airing cupboard on the landing, and the condensation pipe was routed through the loft to the rainwater pipe outside.
    The permanent solution was we rerouted the condensation pipe to the soil stack in the loft..... no more frozen condensation pipe.
  5. Avatar
    This was the advice I got sent yesterday by British Gas.
    I hope it helps someone who is having the same problem.
  6. Avatar
    This is, according to British Gas, the No.1 problem during freezing weather with combi boilers. This is one reason we didn’t choose that kind of boiler when we had a new one installed.
    We don't have a combi, we have a condensing boiler
  7. Avatar
    You require trace heating on the condense pipe
  8. Avatar
    What does the pipe look like? We have a combo boiler
    3/4" (21mm) diameter plastic pipe.
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