Winter Weather Advice - How to thaw a frozen condensate pipe
During winter months and extended periods of low temperatures, it's possible that your condensate pipe may freeze, especially if the pipe exits outside of your property. If your Vaillant boiler is flashing with either a F28 or an F29 code or you fear your condensate pipe is frozen, you can follow these simple steps.
Where to find it
The condensate pipe is usually a white overflow pipe, similar to one you may find on a washing machine or sink waste pipe. It allows your boiler to dispose of condensation to an outside drain via this pipe.
If the liquid from the expelled condensation freezes over, it can cause blockages and build-up of pressure. Not only can this reduce the performance of your central heating system, but you can damage your boiler as a result of the blockage. The pipe will usually be located on the external wall outside from where your boiler is. We’ve included some steps you can take at your home to help solve this issue.
How does it work?
Once the water vapour has been condensed, it turns into water. A condensing boiler, on average, creates around 2 litres of condensate water per hour, and it needs somewhere to go! By having a condensate pipe, the water is safely disposed of with the rest of the waste water, just like a sink or washing machine.
How to protect it
Once you have successfully thawed out the condensate pipe, you can make sure it doesn’t happen again by insulating the condensate pipe. By insulating the pipe, you are reducing the risk of it freezing and blocking again in the future. All good DIY stores should sell pipe insulation, sometimes called pipe lagging and this can be easily fitted with little effort
To insulate your pipes, you should make sure that the water is flowing correctly out of the pipe. Once this is done, you should then measure out the length of the pipe so then you can make sure that you have a sufficient enough amount of insulation. Cut the length you need and fit it around the exposed pipe. For different types of insulation for your condensate pipe, please see further information here.
Impact of a frozen condensate pipe
During cold weather, it’s possible for your condensate pipe to freeze if the pipe is outside of your property as water is passing through the pipe. If this happens, it is most likely that your boiler will fail to start, meaning no heating or hot water.
If a frozen condensate pipe is to blame for your boiler failing to start, it means that you have to defrost the water that has built up within the pipe before it will work again.
How do I know if my condensate pipe is frozen?
Before attempting to thaw a frozen condensate pipe, it’s important to make sure that’s the cause of the problem. The first warning sign that your condensate pipe has frozen may be an error code on your boiler. On Vaillant boilers, you’ll get an F28 or F29 code. If there is another fault code on your boiler, please contact you local Vaillant installer.
Error codes on other makes of boiler may vary, but a tell-tale sign is a gurgling noise coming from the boiler.
If the boiler was working fine up until a bit of a cold snap, there’s a strong chance your issue is a frozen condensate pipe.
If you want more advice on defrosting your condensate pipe, please call a gas safe registered engineer and they will be able to help you. You can find your local Vaillant installer here.