R
rgledhill
Calling all plumbers, calling all plumbers... I have inherited a weird system in my house! It was put in 30 years ago and consists of a monster log-burner, standard cylinder, standard pump etc. The pump runs at medium speed and I've tried to bleed all the radiators but there seems to be virtually no pressure in the system.
If I turn the pump up to full, I get two things - when I try to bleed the rad nearest the pump, it SUCKS air into the system and pumps the hot water straight up the pressurisation / water supply pipe, into the expansion tank!! I'm guessing this shouldn't happen :-/
I've spent some hours now trying to figure out how it's connected together, and now that I have, I think I can see why it happens. The expansion tank is fitted AFTER the pump, before the radiators, so naturally if the radiators are a bit harder to push water through (e.g. some thermostatic valves have turned off etc) then it's pushing the water back up. Surely this is wrong?
Also there seem to be two circuits - one for heating the cylinder (which I don't need as I have an immersion heater for that) and one for the radiators, but they're connected up in different circuits.
All advice very gratefully received! All I can think of is to put a non-return valve in the expansion pipe, and allow it to expand up the venting pipe (?)...
I'm not a plumber but am an engineer so forgive my lack of experience, I'm just trying to understand what should happen next
I've put a picture below - hopefully this can be scaled up to see how it appears to be connected...
Thanks everyone!
Richard
If I turn the pump up to full, I get two things - when I try to bleed the rad nearest the pump, it SUCKS air into the system and pumps the hot water straight up the pressurisation / water supply pipe, into the expansion tank!! I'm guessing this shouldn't happen :-/
I've spent some hours now trying to figure out how it's connected together, and now that I have, I think I can see why it happens. The expansion tank is fitted AFTER the pump, before the radiators, so naturally if the radiators are a bit harder to push water through (e.g. some thermostatic valves have turned off etc) then it's pushing the water back up. Surely this is wrong?
Also there seem to be two circuits - one for heating the cylinder (which I don't need as I have an immersion heater for that) and one for the radiators, but they're connected up in different circuits.
All advice very gratefully received! All I can think of is to put a non-return valve in the expansion pipe, and allow it to expand up the venting pipe (?)...
I'm not a plumber but am an engineer so forgive my lack of experience, I'm just trying to understand what should happen next
I've put a picture below - hopefully this can be scaled up to see how it appears to be connected...
Thanks everyone!
Richard