potterton boiler help

[gareth99]

hi all im in need of some help as im completly out of my depth with this one.... the problem if i turn my hot water on the boiler will light but 30 secs later it will make the loudest banging noise and cut out...

i thought it might be the circulating pump so i replaced it but this aint made any difference

i have a potterton suprima 40L boiler hope this helps please any ideas of what i can do before i call someone out...

 

[Agile]

And if you turn on the heating?

Water in header tank?

Tony

 

[gareth99]

hi there thanks for the reply the banging noise has gone away now after bleeding the rads? there was water in the small tank in the loft and when i called for the heating to come on the boiler would light but then cut out without the noise since fitting the pump and bleeding the rads i have no noise... but if i call for hot water or heating the boiler will fire up for roughly 30 secs then it will cut out leaving the red light flashing i dont now if i might of had more than one problem here.. ive tried turning the temp control right down but to no avail problem still there at high temp and low temp... could this be the pcb?? the fan always works while the boiler is on so dont think its that but hey just need some sound advice of where to look now.got no problem calling some one out just really would like to get a bit of a heads up on this one cheers again

 

[tonybhoy]

Red light flashing is more than likely the PCB, especially if it's the original/old one that's open.

Certainly flashing red light is a boiler problem, solid red light is external, pump, room stat, motorised valves etc.

For a cheap option replacing the thermistor and the high limit stat first should cost about £100 inc labour.

PCB is around £180 plus fitting.

 

[bengasman]

Suprima is known for pcb problems to put it mildly, but the kind of symptoms also question the flow; could be blockage from corrosion or airlock.
Have you tried running it on both ch and dwh together with the boilerstat just high enough to come on?

 

[adlplumbing]

boiler fires up do the pipe get warm?
have you bled the cylinder?