Possible external expansion tank error

[Neil Carroll]

I've just fitted an external expansion vessel to my ferroli as the internal one was passing a lot of water, it's created another problem, it all went well, fitted to return pipe ( i double checked) joint eventually stopped leaking but then.... When I fire up the boiler in burns for about thirty seconds and makes a thud and the pilot goes out.

Now I'm preparing for a good kicking here but I think I've discovered the error, I've put the tank about a foot above the boiler, it will only take a morning to fix, is this likely to be the problem, the pressure is correct, I can't see it being anything else, any advice please? , Thanks.

 

[terryplumb]

Trapped air within the boiler possibly ?

 

[polesapart]

As above. Loosen the compression nut on your EV connection to release any trapped air in the pipework and make sure the cap on the auto air vent in the boiler is not closed. Check boiler manual for first fill/vent procedure.

 

[Neil Carroll]

Thanks, I'll give it a go in the morning

 

[muggles]

Check the pressure in the expansion vessel is set to about 0.7 bar with no pressure in the heating system

 

[Neil Carroll]

Ok, Ive done all that now , no change , I think theres now a PCB problem , to be honest the external vessel addition went well but now it wont click on ignition and all the relays are buzzing , my theory is this , i think power isnt going to parts of the board , stopping it lighting and also maybe not powering the pump (same plug) and therefore the water isnt circulating and its overheating and shutting down . ive ordered a reconditioned pcb to arrive tomorrow ,
if that doesnt work I really think the games up and I need a new boiler , Ill let you know.

Thanks.