How can I tell if the 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:

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 2If 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 3If the boiler does not re-fire and it is emitting a gurgling sound, then it is almost certain that your condense is frozen. If you cannot hear a gurgling noise you should still proceed to check your condense pipe.

Step 4The 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.

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