pot puma 80

[colin3663]

there is a bubbling sound coming from the boiler and hot water coming from the auto air vent we had a new air vent fitted 1 week ago and it is happening again it starts when the heating go's off about 1 hour later it bubbles and hot water spits out from the air vent then we have to top up the pressure the next day or 2 please help

 

[doitall]

Who fixed it the first time

 

[ChrisR]

Check if there's ared light on the circuit board when the boiler should be off. If so the domestic hot water DHW flow switch is stuck on. So the heating would be on until it boils..

 

[colin3663]

the same reg company who fitted the boiler

 

[colin3663]

Check if there's ared light on the circuit board when the boiler should be off. If so the domestic hot water DHW flow switch is stuck on. So the heating would be on until it boils..

thanks i will try and have a look

 

[kevplumb]

so get them back

 

[colin3663]

so get them back

they have been back but it only makes the noise at night when its been on most of the day
they tested it and said it working sound nothing wrong there might be a leek on the rads or pipe work but i can not see any apart from the leek from the air vent ??

 

[ChrisR]

AIr vents don't suddenly leak water, only air or steam. CHECK YOUR RED LIGHT!

 

[PORKY THE PLUMB]

is slow run fan running?

 

[ChrisR]

Good point!

 

[colin3663]

is slow run fan running?

no the fan is off
we have had an expansion tank fitted 18 lts could that be to small

 

[ChrisR]

Without the fan running slow ALL THE TIME, the water in the boiler WILL boil and cut the pilot off.
Further diagnosis is easy with a volt meter.