During
periods of very cold weather, we occasionally receive enquiries from customers whose boilers’ do not appear to be working.
Sometimes this is to do with the condensate discharge pipe freezing and preventing the boiler from operating.
The following information will assist you in identifying whether you have such an issue with your boiler and
what should be done about it.
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:
- your
boiler is a Greenstar gas boiler, or a 28i
- 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 28i boilers you may see a flashing red light instead)
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 refires.
Step 3 If the boiler does not
refire 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 4 The
condensate pipe will be 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?
To thaw a condesate pipe do the following, however, you should exercise extreme
caution at all times when attempting to identify and thaw a condensate pipe.
- Boiling
water poured over the pipe, starting at point near the drain, you will know when it is thawed because you will get running
water/ice out of the condensate pipe
- 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.
More questions and answers about freezing condensate pipes
What does the flashing EA code/blue slow flashing light mean?
There are
various reasons that your boiler may display these codes or lights. They do not necessarily mean your boiler is faulty. A
frozen condensate trap or discharge pipe could cause these codes - refer to the steps above to check.
What is a condensate trap/discharge pipe?
The Greenstar range of gas and
oil boilers dispose of their condensate by means of a syphonic trap, which discharges a given quantity of condensate fluid
at a time to the properties drainage system/pipe work.
The syphonic trap is important because
if the condense fluid were allowed to drip continuously to the drain at the rate it was being produced, then there would be
an increased risk of any externally run condense discharge pipe freezing.
Why might the
condense trap/discharge pipe freeze?
Despite the syphonic trap flushing method, when the
outside temperature is below freezing for a prolonged period of time, externally run discharge pipes, or discharge pipes that
are run through a cold area of your property may freeze
What will happen if my condense
trap/discharge pipe has frozen?
The result of this would be the inability of the condensate
to drain away, which would lead to the ‘backing up’ of the condense, which in turn will cause the boiler to fail
and go to ‘lockout’.
If this happens for a gas boiler, then the boiler will
likely be showing an EA fault code, or alternatively it will show a flashing blue light and the boiler may be emitting a gurgling
sound.
What is ‘condensate’?
Condensate
is moisture gathered from the boiler’s flue and allowed to run back through the boiler to a collection point.
