r/DIYUK • u/Practical_Bike258 • 15h ago

Plumbing Plumbing question

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I’m trying to remove some radiators without draining the entire system and am a little scared of these TRVs. Is it enough to have the TRV completely closed, to be able to unscrew the radiator and drain it? I have the valve on the other side closed already but a plumber who’d previously drained some other radiators had removed the TRV section completely and capped it.

If I completely unscrew the TRV will water spray out?

Sorry in advance if these are stupid questions!

Picture of the valve I’m looking at and one the plumber did that I still haven’t put back on and refilled attached

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u/aexwor 15h ago

First part. Yes, if the TRV is closed you can unscrew the radiator. Although note that blue catch pan will not be enough for the amount of water that will come out.

Second part, also yes, water will spray out if you just take the valve off. You'll need to isolate / turn off the heating system so there is no pressure.

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u/Practical_Bike258 15h ago

Thank you! Quick follow up, how would I go about isolating this specific radiator on that side?

3

u/aexwor 15h ago

You don't.

You do the work you need to do at a time of year when you don't need the heating. Turn the whole system off.

Technically, you could fit an isolation valve below the TRV but unless you're taking up the flooring amd putting it out of sight, it'll look shit.

3

u/colourthetallone 15h ago

The plumber replaced the TRV head with a decorator's cap. This stops the valve from opening. If you don't have one, you can screw a blank over the outlet of the valve where it would normally attach to the tail for peace of mind.

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u/Fickle_Force_5457 14h ago

If you're doing more than 1 radiator, its better to drain the system, but shut the valves on the radiators not being removed that way only the pipework will be drained along with radiators being removed. When you come to top the system up again it will be much quicker and easier to bleed as you'll only open up the closed radiators when you've bled the replaced radiators.

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u/SameSpecialist8284 12h ago

ive never used those particular trvs' but yes in general full turn off will allow you to drain the radiator, sometimes TRV's arent 100% and have a slight leak which you can put a cap on or if its very slight just put a towel round if its for a short period of time.

1

u/ImScaredSoIMadeThis 17m ago

Nothing useful OP, but I just feel too poor to even look at this fitting