How to prevent your boiler condensate pipe from freezing?

You will undoubtedly remember the extremely cold weather with snow and frost we had in the UK back in March 2018. During that period we had huge volumes of calls from customers in Plymouth with emergency boiler repairs.

The reason for these boilers breakdowns was that the the condensate pipe, a white plastic pipe that runs from your boiler to outside, had been freezing up and causing the boiler to show a fault code.

Now we are well and truly in to winter there is the concern that temperatures could drop again, causing the same boiler faults as in March. We are now carrying out work for our customers to prevent frozen condensate pipes occurring again.

Ways to prevent condensate pipes freezing

Gas safe have now issued a technical bulletin to all gas safe registered heating engineers about best practice when installing condensate pipes to prevent this happening.

1. Run the condensate pipe internally to a waste pipe via gravity. wherever possible. Depending on the location of your boiler this may not be possible but if it is then this is the best way to stop the freezing
2. Install a condensate pump if it is not possible to get the required fall for gravity to drain the water away. This gives more flexibility to run the pipes internally. If the pipe is to run through I heated areas like a loft space or garage then insulation is required
3. Run and insulation the pipe externally – this the last resort to run a pipe externally. If so the pipe should be a minimum diameter of 32mm (1” 1/4) waste pipe, a maximum of 3 meters, be s steep as possible and be lagged with 19mm type o insulation

If you’d like more information on this a you can visit Or if you’d like to discuss your options we can provide a free survey with quotes to install the preventive measures. Call us on 01752 957729