Pump in the return pipework - LSV on which side?

[bhm1712]

if you have your pump in the return pipe, should the lock shield valve be on the return or flow side of the rad?

i understood that it doesnt matter whether its on the flow or return, but with the system being under negative pressure, i wondered does it make a difference, as a friend of mine says that if you have the LSV on the flow side it can affect the pressure adversly when its a pumped return

 

[cross thread]

i was always taught locsheild on the return

 

[ianniann]

Lockshield on the return side is the usual recommendation. It will work either way so don't panic, but there's less chance of a blocked valve that way round. The pump won't see much difference either way.

 

[holty]

depends were your trv is situated if you have one.pointless having the trv to the left or right if its near a wall. so basically the trv should be situated in a point were it would pick up heat more often.e.g center rather than a corner of a room.

 

[bhm1712]

i dont have TRV's only control valves and LSV's

 

[TicklyT]

Usually the innards of both lockshield and wheelhead valves are identical, it's just the plastic knob fitted on top that's different.

 

[bhm1712]

i know that.......

but all im asking is, the normal is to have the lock shield valve ( the one without the control knob on top) on the return pipe, but on a system under negative pressure ( with pump in the return) does it matter??

it seems not from the other posts

 

[tamz]

does it matter??

Not in the least