TRV problem

Here's a wild guess from someone with only a little experience of fitting them :-) Does it have a 'pin', like all mine have? Can you push it in if you press hard enough? I have noticed that unless you get the heads in exactly the right position (they have locators to stop them turning), they tend to stand proud a bit.

As I said above "the spindle appears to move freely"

Chris

Why not try swapping a known working TRV with the suspect one?

That should show if it is the TRV or the radiator valve.

Cheers

Dave R

As I already said "Having put back the original thermostatic head..."

This was working fine when I replaced it with the electronic head, as are all the others around the house.

Chris

My understanding is that TRV is Open when the pin is fully up/out and closed when pin is fully down/in. So if the pin will move down freely ( and fully) but the valve remains Open something is broken inside.

I find a WET/DRY vacuum cleaner an essential tool when fiddling with radiators and plumbing , amazing how good they are in preventing water hitting the floor or worse still the carpet.

Do you had a "Decorators" cap to fit - this holds the pin down. See if that stops the flow. Also make sure the head has dropped into its seating (Hex).

I'm giving this a try right now.

I can see how that could be a problem, but it looked as though it was properly aligned.

Chris

It is sometimes possible to change the innards without drips and mess, i.e.

No idea as to price, if it fits, etc., just HTH.

Thomas Prufer

clever

Ouch.

Specialized tool, I guess, and would pay for itself quickly for a pro.

Ball valve, gland/stuffing box off a valve, bleed valve, bit of work -- might actually be possible to diy one if one had a lathe etc.

Thomas Prufer

I've never tried this but I've been told that if you release the pressure from a presurised system, close all the lock shield valves etc. you can replace a failed lock shield valve 'like for like' - provided you are quick and have everything to hand, with minimal mess.

The theory is, there is no real 'head' of water to allow the water the pipes to leak, even the water in the local rad is held as the air has only one entry point you can restrict with your thumb etc for part of the time.

I was also surprised how the person who refitted our bathroom rerouted the radiator pipe etc without having to drain the system, including inserting new pipe etc. I had assumed he used freezer but he assure me he didn't. Unfortunately, I didn't see how he did it. There certainly wasn't a mess / puddle of water etc. (We have a pumped, no presurised system.) I'm pretty sure he put a cork (or similar) in the header tank.