alanch
Well-Known Member
Having removed my gas water heaters, I now need to fit a calorifier of about 40 lts. As all my taps are microswitch controlled, do I need to fit an accumulator on the hot or cold water side of the calorifier?
Do I need an accumulator tank?
- Thread starter alanch
- Start date
Cloven
Well-Known Member
Yes. Actually I have two, one on the cold after the pump and one on the hot just after the calorifier. Not sure you need both but that's what we have.
sailinglegend420
Well-Known Member
Two is best but one can work.
The calorifier needs an expansion tank to stop the pressure building up when the hot water expands. Without one the pressure release valve will open and waste hot water into the bilges or to a thru hull fitting.
If there is no non-return valve on the cold water inlet to the calorifier then the pressure can be released back into the cold water supply and into an accumulator in the cold feed. This could also feed some hot water into the cold supply - but should not cause a problem. We now have this setup - with a variable speed pump - and the pump cycling and noise is now cut down to almost nothing.
The calorifier needs an expansion tank to stop the pressure building up when the hot water expands. Without one the pressure release valve will open and waste hot water into the bilges or to a thru hull fitting.
If there is no non-return valve on the cold water inlet to the calorifier then the pressure can be released back into the cold water supply and into an accumulator in the cold feed. This could also feed some hot water into the cold supply - but should not cause a problem. We now have this setup - with a variable speed pump - and the pump cycling and noise is now cut down to almost nothing.
vyv_cox
Well-Known Member
I think the other posters may be discussing a pressurised supply, not a microswitched one. I can't see any point in having an accumulator in your case, how will it contribute anything? Particularly if you have a centrifugal pump, which will allow water to backflow through itself.
alanch
Well-Known Member
Yes, the main thrust of the question was regarding the microswitch taps. The FW pump is a diaphragm pump which I think will prevent a backflow through the cold side, (therefore a NR valve is not required) and not being a pressurised system there is no requirement to ease pump cycling with an accumulator in the cold supply between pump and calorifier. To allow for expansion of the hot water and to prevent excessive leakage from the safety valve then an expansion tank in the hot line is needed. Thats my current thinking anyway. Unless someone knows different!