Changing a broken TRV

[allysunlife]

Hi folks,

I have a combi boiler.

The trv for one of the rads needs changing.

Do i follow these steps:
Shut boiler
Make sure the lockshield side is closed
Slowly undo trv radiator nut and drain water from radiator.
Change TRV
Pressurise the system.

Please advise.

 

[ShaunCorbs]

Turn boiler off electrically
Drain radiator system by a drain off
Drain the rad with the faulty trv on
Replace trv
Refill and new inhibitor
Turn boiler back on electrically

 

[allysunlife]

Turn boiler off electrically
Drain radiator system by a drain off
Drain the rad with the faulty trv on
Replace trv
Refill and new inhibitor
Turn boiler back on electrically

Thanks, Shaun.
My lockshield was leaking a month or so ago. An engineer followed the above but he did not drain the system. He just undid the lockshield nut and let the water drain out of the Radiator. Then changed the lockshield.

But because its the TRV i must drain the entire system?

 

[ShaunCorbs]

He must of took the pressure off first

 

[allysunlife]

He must of took the pressure off first

Ahh you mean emptied the system first. I see.
Thanks Shaun. Very helpful.

 

[king of pipes]

It is possible to change the Trv like for like by just taking the pressure off the system , you need a container and wet vac and the theory is you are trying to pull a vacuum on the pipe if air can't get in the water won't come out isolate both valves drain out the rad, open the trv until flow slows to a manageable amount or stops work quickly because it not always a successful if that air gets in . Kop

 

[Enthalpy]

Replace Radiator Valve In Depth Detailed Instruction, with Out Draining the System. Part 2.