How to fix a frozen boiler condensate pipe

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Diagnosing a frozen condensate pipe

If your boiler starts developing random faults which are preventing your central heating or hot water from operating as it normally. Then it may be worth looking to see if your boiler is being affected by a frozen condensate pipe.

To establish if the issue is actually the frozen condensate pipe, please check your boiler first as it will most likely be showing either some flashing lights or some form of fault code.  It is advisable to check the manufacturer guidance that will have been supplied with your boiler to see if the code relates to a frozen pipe problem. Other signs include the sound of a “slurping watery” sound when your boiler is providing heat or hot water.

Dealing with a frozen condensate pipe

Reset Boiler: By resetting your boiler, sometimes you may find that the issue has managed to resolve itself. If the frozen pipe has since thawed, the error(s) on your boiler may have cleared.  If the fault is still there, then it’s time to try and check outside.  If you are not able to go outside to check or the weather conditions are icy, please get in touch with us.

Locate external pipe (outside): The condensate pipe removes water from the boiler. In most installations, you will find a white or grey plastic pipe coming out from the location of your boiler to the outside wall of your home.  As a large amount of this pipe is exposed to the outside conditions, during sub-zero temperatures, any water within the pipe will freeze and block the pipe.

Time to thaw: The easiest way to deal with a frozen condensate pipe is to put it in contact with warm water.  If you are able to do this, a couple of jugs of warm water poured over the exterior of the pipework will eventually increase the temperature within the pipe and help the ice blockage to subside.
(Please note: It’s important that you refrain from using boiling water.  However likely it is to melt the ice quicker, you may cause more damage as the extreme contrast in temperatures may cause the plastic pipe to crack. Never go up a ladder or stand on a chair or bin to unfreeze a condensate pipe.)

Reset Boiler (again): With the frozen blockage hopefully resolved, please reset your boiler again. If the fault persists, please contact us to arrange for an engineer to visit.

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