Gate valve

[moosehead]

There is a gate valve on our hot water heating system - 22m - fitted on the return run of the HW heating pipe. Should this valve be fully open? Plumber who 'installed' our system had this barely open.

 

[softlad1971]

Its a bypass to stop the boiler overheating if all the trv,s shut down. You also have one on some boilers with a low water content heat exchanger. It should only be open a little. Dont shut it fully.

 

[moosehead]

Thanks SL, but the gate valve is not on the CH circuit but the HW, bottom pipe coming out of the emersion tank?

AOI?

 

[kevplumb]

here

 

[moosehead]

Don't thinks it's a by-pass as the pipe on which the GV sits goes directly back to the boiler from the HW tank

 

[jas05]

the valve is to restrict the flow of water going through the coil
so put it back to the setting where your plumber left it

 

[moosehead]

Thanks Jas,

Assume this valve should be fully open' however, when draining/re-filling the system.

Also by restricting the flow through the coil is this similar to balancing central heating?