Problem with Ferroli Sys 10-23 boiler

[Mikeycollins]

Hi

I had this bolier serviced and a new Myson motorised valve fitter a couple of weeks ago. Today the system is not working at all. I have observed, that when I switch the system on the gas lights, the pressure meter rises quite quickly to two bar and then the boiler makes a bang and the system switches off and cannot be restarted for 15 minutes when the same happens again.

I cannot get hold of the plumber today so it looks like it will have to wait until Monday. I have bled the system and took the silver screw out of the Grundfos Selectric 15/50 Pump pump to drain/vent it. I have turned the pump manually and I have powered up the system with the screw out. I do not see the pump turning and have come to the conclusion that the Grundfos Selectric 15/50 Pump is the fault. Does anyone think I am correct?

Thanks for your help

 

[oldplumber]

Im unsure as to whether this is a system boiler or not, but as you are talking rising pressure,it probably is, as , it is showing all the signs of a failed expansion vessel that needs recharging or replacing. the bang you hear will be more of a clatter as the pressure relief valve works allowing the system to relieve the high pressure and there will be an outflow of water via the drain normally to the outside wall. get in your plumber to check it out, this is not something that is his fault, as they can fail at anytime, and its not something you can inspect really other than by checking the expn vssl pressure at service time, which is pointless as if the system is working ok, proves the vessel is ok

 

[Mikeycollins]

I hope it isn't the expansion vessel as when looking at it I don't see anyway to get to it without dismantling the whole boiler; is that correct or am I missing something?

 

[stevetheplumber]

its most likly to be pump not working alllowing boiler to go straight to overheat it needs to be checked to ensure theres power to it
if theres power and it doesnt turn its pump simples

 

[Mikeycollins]

A couple of questions relating to the above reply. Why would the pump not be receiving power if the rest of the system is and if I weere to replace the pump myself is it simply a case of removing the pump motor from the body and replacing it, as you would with motorised valves?