evening all,
could someone have a look at the following pic and tell me what the purpose of the stopcock is in this setup? and should it be open or closed?



water pump

the top pipe in the pic comes from the 3-way actuator above the water pump and goes into the water tank. the bottom pipe also comes out of the water tank but then feeds back into just above the water pump.

cheers,

mads

[Edited on 28/10/12 by mads]

Usually done as a balance valve to insure a minimum flow through pump etc even if all radiators are off. Usually set halfway between open and closed depending on system

You'd still get flow through the pump with the radiators off unless you were running a single pipe system. If it's closed you will get no domestic hot water.

Bypass if all rads are shut the pump will be pushing against it with nowhere to go should be slighty open.

Eta you would still get a flow on a 1 pipe system but not a conventional 2 pipe so wouldnt have this on 1 piper

[Edited on 28/10/12 by adam1985]

thanks for the replies folks. so follow up question is, if this valve was fully open, should it affect the downstairs radiators and stop them getting hot? that is what seems to have happened. I closed the valve fully and the bottom radiators are working again.