oil combi 90

[Daddy Mac]

i have a oil combi boiler, the hot water pump runs constant when the boiler fires up even though the hot tap is closed, the water gets that hot it bursts the pipe at back of boiler, i have tried disconecting the flow switch but nothing, i replaced the relay head and it all worked fine like its supposed to but now its been a couple of days and its back doing the same, the central heating does not work as its constantly heating the water, any advice would be great thanks.

 

[kimbo]

Need to know make of boiler. Combis are also best left to professionals who know what they are doing.

 

[Daddy Mac]

its a firebird

 

[dontknowitall]

Difficult to make out but perhaps a pump is at fault.

 

[SimonG]

In my opinion the Firebird is probably the worst combi to work on. Difficult to say without it being in front of me and getting out my test kit. I know you have said you dropped out the flow switch, but have you tried isolating the cold feed to the combi? Also worried about the 'plastic' pipe that you said keeps bursting in your pm.

 

[kimbo]

These boilers have a pump overrun on them and also the pump is activated when the he store is being replenished. I presume the discharge is the pressure relief valve. This could be faulty . To be honest it could be any number of things, your best bet would be getting an engineer out preferably someone who knows firebird boilers.