Scott Findlay Plumbing & Heating Engineers

Winter Freeze

Freezing condensate pipe (How to keep your boiler operating)

We would like to advise you on what you can do to prevent your Worcester Boiler's condensate pipe from freezing and how you can protect your home internal hot and cold water supply pipework from freezing.

How can I tell if my boiler's condense trap/discharge pipe has frozen?

Step 1

  • It's possible that your boiler's condense trap/discharge pipe has frozen if all 3 of these statements are correct.
  • If all 3 statements are true, you should now try to reset your boiler. This can be done by holding in the reset button (this can be found on the boiler control panel) for 10 seconds. Once you have released the button you should wait 2 to 3 minutes to see if the boiler re-fires.
  • The outside temperature is or has been below freezing
  • Your boiler is displaying either an EA fault code, a D5 code or is displaying a flashing blue light (for 26CDi boilers you may see a flashing red light instead).
  • Your boiler is a Greenstar gas boiler, or a 26 CDi .

Step 2

If all 3 statements are true, you should now try to reset your boiler. This can be done by holding in the reset button (this can be found on the boiler control panel) for 10 seconds. Once you have released the button you should wait 2 to 3 minutes to see if the boiler re-fires.

Step 3

If the boiler does not re-fire and it is emitting a gurgling sound, then it is almost certain that your condensate is frozen. If you cannot hear a gurgling noise you should still proceed to check your condensate pipe.

Step 4

The condensate pipe is a plastic pipe (black, white or grey), coming from the bottom of your boiler. If this pipe is less than 32mm in diameter and runs outside of the property or through a non-heated area then it should be fully insulated with waterproof lagging. If it is not fully lagged and the 3 criteria (in step 1 above) apply then it is likely that it is frozen and needs to be thawed.

How can the condensate pipe be thawed?

You should exercise extreme caution at all times when attempting to identify and thaw a condensate pipe.

  • You should only attempt to thaw a condense pipe that is at ground level and which is easily accessible to you. Under no circumstances should you attempt to thaw a condense pipe which is at height, without the assistance of a professionally trained engineer.
  • A hot water bottle or heat wrap (like the ones that can be used to ease muscle discomfort) would be a suitable and safe way of thawing the condense pipe. Hold the hot water bottle or warmed heat wrap around the condensate pipe to thaw it.
  • Once thawed, the boiler must be reset. This can be done by holding the reset button in for 10 seconds and then waiting 2 to 3 minutes for the boiler to refire.

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