TRV change on rad attached to hot water loop

[Thehalp]

Hi,

I have changed TRVs before, but only on a normal central heating loop, I have drained the loop then done the job. I need to change the TRV on a bathroom radiator that is connected to the hot water loop. If I turned the cold water off at the stockcock and ran the hot water taps downstairs, would I remove enough pressure from the loop to do the TRV change?

 

[terryplumb]

Is the " hot water loop" connected to a central heating system with a hot water cylinder ?
If so, running hot water taps is irrelevant. You need to drain the system at least to a point lower than the radiator you are working on.

 

[Wayners]

Tank in loft you can plug or combination boiler will have vacuum so no need to drain either system.
Sometimes easier and safer to drain though