Need to drain loft bathroom radiator to install TRV.

[johnw100]

Hey all
So we had our loft converted last winter and the plumbers didn’t put a trv on the the two radiators up there, it’s just open/close valves.
So I’m going to fit some myself. Am going to switch off the boiler which is pressurised system. There’s a set of valves in the landing below cupboard for the loft. See photo. Think it’s the two on the left as the others go into the 1st floor bathroom.

Think I could just turn off the inlet and then drain from a downstairs radiator until the radiators in the loft are empty.
Then once fitted the trv can just fill the system from the boiler again?

Thanks

 

[CBW]

No need for all of that.

Isolate both rads, open bleed vent on the one you’re working on and when water has stopped running (approx 20 seconds), undo the connection on the valve you’re changing that enters the radiator and plug the tail with a split 15mm stop end (if possible) open the valve back up into a suitable receptacle, once water has stopped change valve over connecting back up to the rad tail.

Repeat for 2nd rad and when you’re done open up the other end of the valve fill, system, venting the 2 rads and check for leaks.

 

[johnw100]

Thanks Chris.

Is this video a good example of what your saying there.. But i`d need to turn off these valves in the photo first?