25 October 2021

Thawing A Frozen Condensate Pipe


Even the most well-maintained boiler will struggle to work properly if the condensate pipe freezes, and as the colder weather draws in, it’s important to know what to do if your boiler stops working.

What is a condensate pipe?

The condensate pipe carries condensation from your boiler to the outside drain. It’s usually made of white or grey plastic and travels from your boiler through the wall and directly outside where your boiler is located.

Common signs the condensate pipe is frozen

  1. Gurgling/bubbling noises coming from the boiler

  2. Your boiler fails to start

  3. A fault code/warning light is on the boiler’s display (this depends on the make/model of your boiler)

 How to find the frozen portion of the pipe

Your pipe will typically be frozen at the most exposed point. Run your hands along the pipe until you find the section which feels colder than the rest.

 How to thaw the pipe

Pour hot water along the length of the pipe, repeating until its thawed. Don’t use boiling water as this could crack or damage the pipe. If you’re using your kettle to heat the water, leave it to cool for 15 minutes or so (you could also use a hot water bottle or a microwaveable heating pack).

Reset your boiler

Once you’re happy that the frozen section of your condensate pipe is melted, you can reset your boiler – use your manufacturer’s guidelines if you’re unsure how to do this. You should not find that your boiler works as expected.

How to stop this happening again

Leaving your heating on overnight can help to stop this happening by keeping your pipes warm while the weather’s cold. You could also buy foam pipe insulation to wrap the pipe in; this is available from most DIY stores.

To find out more about our boiler and central heating insurance, plumbing and drainage insurance or other types of home care cover plans, such as Complete Home Emergency plans and home appliances cover, contact our friendly team on 0330 09 48 301 or get a quote online.