During the winter months, when the weather is particularly cold, boiler condensate pipes can freeze.

If your boiler is showing an error code or a series of flashing lights on a particularly cold day, check your boiler manual as a frozen condensate pipe could be the problem. The following steps will help you to defrost the pipe.

Step 1 – Locate the boiler condensate pipe

It tends to be either a white or black plastic pipe that runs from your boiler to outside and down to the nearest drain.  As this pipe is exposed to outside conditions it is easy for the pipe to freeze causing the water inside to turn to ice and block the pipe to the boiler.


Step 2 – Unblock the drain

Remove any ice or leaves etc. from the drain that the condensate pipe runs into

Step 3 – Defrost the pipe

The quickest way to defrost a frozen condensate pipe is to pour boiling hot water directly over it. Start at the end of the pipe that is closest to the drain and then work your way up the pipe until you reach the top where it enters the wall.  You may need to do this more than once to thaw all of the ice.  You may also find that you need to repeat this step more than once in a day if the weather is particularly cold and the pipe freezes again.

Step 4 – Re-set your boiler

Once the pipe has fully thawed return to your boiler and press the re-set button. Your boiler should then begin to operate as normal again.

If the boiler continues to display an error code/flashing lights call us on 0191 5492316 as the boiler may have another fault.

If you have persistent problems with your condensate pipe freezing we can advise on different methods of insulating exterior pipework to stop it from happening.