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Cold nights led to a frozen boiler?

Have you woken up to your boiler not working unexpectedly? If it’s been particularly cold outside lately it could be down to a frozen condensate pipe. Learn how to fix it when it freezes and how to avoid it happening again in the future.

How to fix a frozen boiler condensate pipe

Your boiler's there to keep your home warm and cosy, especially during the cold winter months, so waking up to it not working because of frozen condensate pipes is the last thing you want. Thankfully, a lot of the time you can fix this yourself without needing to call out an engineer. If you've been unable to resolve this issue, check out our range of new boilers. 

Safety first

Concerning boiler issues, we always recommend that you call a Gas Safe engineer to inspect the problem. There are a few checks you can undertake yourself before calling in the professionals, but only if you feel confident to do so. 

What is a condensate pipe?

To keep the boiler as efficient as possible (around 95%), it recovers heat from the waste gases produced and uses this to heat the water circulating through your radiators. This reduces the amount of heat that would otherwise be simply lost to the outside.

The waste gases are mainly water vapour and as the condensation process cools them, some of the vapour turns back into liquid, or ‘condensate’.  This is then drained away by the condensate pipe.

Where is the condensate pipe on a boiler?

The condensate pipe is easily located as it's the only plastic pipe connected to the boiler. It runs from the boiler to a drain which can be inside or outside your property. Where your condensate pipe connects to a drain or soakaway outside it can freeze in cold weather.

How to check if your boiler condensate pipe is frozen

Frozen boiler condensate pipes are fairly common during colder months, so if your boiler unexpectedly stops working in winter, this is probably the cause. The most obvious sign of a frozen condensate pipe is suddenly having no hot water or heating but your boiler has other ways of letting you know if there’s a problem.

Listen out for any gurgling noises coming from your boiler as this may also be a sign of a frozen condensate pipe. Or, if you have a digital display on a more modern, new boiler, it might prompt you with an error message. 

How to thaw a frozen boiler condensate pipe

Thawing a frozen boiler condensate pipe's a relatively simple process. Locate the condensate pipe outside your property and pour warm (not boiling) water over it. After a few minutes it should've thawed and you can reset your boiler. If you feel uncomfortable doing any of these things then we’d advise that you call a Gas Safe engineer to come and investigate the problem.

If you’ve attempted this process yourself and it hasn’t worked, contact a Gas Safe engineer to come out and check your pipework for any other issues. Check out the video guide for a Worcester Bosch boiler.  

How to prevent your condensate pipe freezing

There are a few ways you can prevent your boiler condensate pipe from freezing in the future. We’d always suggest contacting a Gas Safe engineer to help make these changes.

Insulation and protection

Use a foam pipe insulator to cover the pipe to keep it from freezing, and protect the pipe end in the drainage system by installing a drain cover.

Rerouting

Change the path that your external pipework currently follows so that it’s mostly fitted inside the property to lower the chances of freezing.

Increase fall angle of pipe

This'll help to improve water flow and avoid the risk freezing during the coldest temperatures.

Install wider piping

Replacing the pipe for one with a larger diameter will improve the flow and also minimise the risk of freezing.

A little help and advice

Residential