Ravenheat RSF 820/20 boiler - diverter valve

[RichardAJ]

Ravenheat RSF 820/20 boiler

Hi.
I have been having problems with getting the boiler to heat the water for a shower. Found out that it was the diverter value that wasn’t activating the attached microswitch.

The problem now is that I don’t have a manual for the boiler and I believe that I have turned off all of the isolation values leading to the boiler and drained the expansion tank BUT when I try to un-screw the pipe from the diverter value to the exchanger? there is a lot of water pressure. Pressure goes away when I turn a tap on downstairs – so what I need to know is what have I forgotten to off / shut down so that I can get this (very stupidly placed) value out of the boiler.

Any help will be gratefully received

 

[fazedup71]

i wouldn't touch any of the isolation valves on the boiler, you might end up with leak city! does the boiler work when you turn a tap on? if it does then it might be the shower valve that is the problem, it also sounds like you have not isolated the cold inlet

 

[RichardAJ]

The boiler doesn't kick in when any hot water tap is turned on as the diverter valve doesn't push the rod far enough to activate the micro switch.

should i leave the isolation valves alone - aren't they there for that job ?

 

[fazedup71]

yes they are for isolating the boiler but they normally leak if you operate them. Sounds like the diaphragm has gone

 

[RichardAJ]

can i drain the system by just turning off the mains supply to the house and draining the expansion tank?. This way i can leave all of the isolation valves alone.