For gas advice, central heating installation and servicing and air source heat pumps call us on

Frozen Condensate Pipe Problem?

In recent winters we have experienced prolong spells of cold weather (down to –20ºC in some areas). As a result of this the ‘Condensate Drainage Pipe’ from condensing boilers has occasionally frozen. This happens when the pipe is run externally for some of its length. When this pipe freezes it causes a blockage and stops the condensate from the boiler to the waste in turn stopping the boiler from working.

You can usually tell if this pipe is frozen by a fault code flashing on the boilers digital display (usually F1 or F4 on Glowworm Boilers). There are a number of ways householders may try to thaw this pipe out themselves.

Thawing Frozen Condensate Pipes

1. Locate the blockage

The Condensate pipe usually freezes at the most exposed point outside. This is usually the open end of the pipe, at a bend or elbow or where there is a dip in the pipe where condense can collect.

2. Thaw the Frozen Pipe

The Condensate can be thawed in a number of ways. By applying a hot water bottle, a microwaveable heat pack, warm cloths wrapped around the blockage or by pouring warm water onto the pipe. It is important that you do not use boiling water.
Please make sure that the pipe is easily reached from ground level—also be aware that if you are pouring water onto the pipe this can also quickly freeze on the ground causing a slip hazard.

3. Reset/ Restart the boiler

This can be done by pressing the reset button on the front of the boiler or by switching it back on.



There are a few things that be can done to try and prevent this from happening.
1. Lag the external pipes

2. During the cold spell run the heating with the thermostat on maximum. Remember, you can adjust each room temperature using the radiator valves. Don’t forget to turn the thermostat down once the weather has warmed up!

3. Temporarily keep the heating on continuous (24hrs) while it is particularly cold, leaving that thermostat on or around 15ºC at night. Again don't forget to return it to normal settings when the weather warms up!

Close Message Warning

This web site uses cookies for functionality and analysis purposes. These do not give us, or any third party, access to your computer or any personal information about you. For more information please read our privacy policy.