Plumbing question. - replacing a trv

Adam

Adam

Adam

Soldato
Joined
18 Oct 2002
Posts
9,238
So in taking my radiators off the wall the TRV now spins on the pipe and is leaking from the bottom nut. It doesn't seem hugely difficult to replace as long as I drain the system. I have 2 questions:

1) I have removed 3 upstairs radiators to paint behind them, before I drain the system will I need to put them back on the wall?

2) I have turned the stop **** off so no longer have any water (seems to have switched the cold off but not hot) do I need to do anything else to stop the flow of water to the broken TRV?
 
I don't know about your questions but it will have turned the hot water off as well you just won't notice until you've drained the tank.
 
Thanks, I don't think the hot water supplies the radiators right? Isn't that cold water heated up by the boiler? Perhaps there is some water in the pipes that need to drop out.
 
No need to refit radiators, just make sure trv & check are turned off before draining system.

Even though your turn off the trv & lock shield, there will some water in the radiator, so have a container handy, & protect the carpet, as it may stain it.
Also switch off the boiler.

Just need to replace the brass olive, it's easy to cut old olive with a junior hacksaw, just deep enough not to damage pipe, & prise it open with a screwdriver to remove it,might need some ptfe around the threads, & DON'T over tighten the fitting.
 
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Thanks for the comments so far.

Here is an image of the problem, the TRV spins on the pipe and it only stops dripping if I pull the TRV upwards.

Nightglow: will the replacement olive and fittings be included with the new TRV?
 
If you're buying new TRVs consider the individually programmable ones. They could save you a lot of money in the long run by turning themselves off when not needed.
 
Thanks everyone! Before I left the house for the day I noticed the TRV leaking more and wasn't confident leaving it over night with a bucket under it. I therefore had no choice but to drain the system.

I did this by tying up both ball valves in the big and small tank but I think it was only the smaller tank I needed to do really. I then opened the TRV so the water flowed in to the bucket which took about 1 and a half in total. When that finished I turned the stop **** off to be sure.

Is there a maximum time I can leave the system drained down? To refill it I just untie the ball valves and add inhibitor to a towel radiator for example?

I'm going to replace all the TRV's and lock shield valves upstairs. I'll go for Drayton TR4 as they look decent and get good reviews.

Edit: the house has microbore pipes, do I need to consider anything or will a 15mm TRV be sufficient?
 
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You will need to check the size of your pipe then buy a TRV to fit so you can buy 10mm TRV. Some trvs also have a 15mm to 10mm reducer that's if your pipes are 10mm of course could be even 8mm...
 
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