TRV Pain in the ass

Buford T Justice

Ok, I'm getting pissed off with the TRV in my sitting room. I had a feeling that it wasn't working right, and now I know its not. I've even turned it off fully, and it still blazes heat.

I took the head off and I pushed the wee head down, was a little stiff but then started to move fine. Still no different once I put the head on though. Am i missing something, or what's the problem with this thing does anyone think?

About 6 months ago, I added a sludge remover for a week or two, drained the system and added an inhibitor to it, if it helps.

Just wondering if its anything obvious, as I'd rather not have to go to the hassle of draining the system to replace the valve

JohnnieK

Try pushing the pin down before the heating comes on. If it dose not heat up then you know the valve is working fine and all you have to do is replace the head. You can take the head with you to any plumbing suppliers i.e. Heatmerchants, DPL, Chadwicks and they will help you. Do you know the make?

Buford T Justice

They're terrier brand valves, and were bought in Heatmerchants about three years ago. Must try that and bring the head down.

neeb

Does the pin in the head turn when you change it from 5-0?

Buford T Justice

neeb wrote: »

Does the pin in the head turn when you change it from 5-0?

Yup, it moves up and down as it should. The scope of movement in the pin on the valve is relatively short though. How much movement should it have?

Sparkpea

when the head is closed the pin in the head should be stuck out far and u should not be able to push it in, when open then the pin in the head should be fully in. Its the head that will be faulty rather than the valve. I suggest you take a head off a working rad and compare the pin movement in it to the suspected faulty head.

Buford T Justice

Sparkpea wrote: »

when the head is closed the pin in the head should be stuck out far and u should not be able to push it in, when open then the pin in the head should be fully in. Its the head that will be faulty rather than the valve. I suggest you take a head off a working rad and compare the pin movement in it to the suspected faulty head.

Thats just it though, the pins move up and down the same, I've checked with another TRV. Unless the tip of the shaft has broken off perhaps?

Sparkpea

maybe, still believe its the head more than anything. what about putting a working head from another room on the living room valve for a few days, if it works then you know its the head for sure..

Buford T Justice

Sparkpea wrote: »

maybe, still believe its the head more than anything. what about putting a working head from another room on the living room valve for a few days, if it works then you know its the head for sure..

Switched heads and turned the rad off entirely. Put heating on and it still heated the rad, albeit slower than normal..

I do remember that when I had to move the rad in the kitchen during renovations, I took the rad off and the valve kept leaking constantly. I had to replace it entirely, so I'm wondering whats the likelyhood of having a few duff valves. Has anyone had problems with TV's in the past?

Sparkpea

Fingers McGee wrote: »

Switched heads and turned the rad off entirely. Put heating on and it still heated the rad, albeit slower than normal..

I do remember that when I had to move the rad in the kitchen during renovations, I took the rad off and the valve kept leaking constantly. I had to replace it entirely, so I'm wondering whats the likelyhood of having a few duff valves. Has anyone had problems with TV's in the past?

haven't used terrier valves myself, stick to myson or danfoss. replacing it is probably your next option...

Buford T Justice

Sparkpea wrote: »

haven't used terrier valves myself, stick to myson or danfoss. replacing it is probably your next option...

Shit. Really don't want to do that. The missus won't want me doing that. She think it works so its fine. Need to try to explain the point of TRV's but I don't think she'll be to interested because 'isn't it hot'

it also says 'pegler' on the back of the head, if it matters.

Sparkpea

yeah they are pegler terrier valves

if you're able to do it yourself why not send her out shopping and do a quick change, 1hr max will do it, no need to change the box and rings. is it an open or closed system?

Buford T Justice

Sparkpea wrote: »

yeah they are pegler terrier valves

if you're able to do it yourself why not send her out shopping and do a quick change, 1hr max will do it, no need to change the box and rings. is it an open or closed system?

Its open. Would need to get another bottle of fernox and drain the system down. None of which is a problem to do, its just trying to get it done even on the sly when she's out or away. Bit peeved about it since I only de sludged and put in an inhibitor about 3 months ago. Waste of feckin money now....

Sparkpea

nah u dont need to drain the system down, just plug it

by this I mean cap off the expansion (speedfit or compression stopend), if you've a gatevalve on your cold feed close it or again cap it off, this creates a vacuum. then close the rad valves on both sides of the rad that you're going to change the valve. what I do is disconnect the side with the trv on it and use a compression stopend to screw onto the tail of the rad to stop the water in the rad escaping. then break the seal slightly on the pipe coming into the valve just enough to let you turn the valve so that its facing you, tighten it up again. open the valve into a bucket which should drain about 2-3litres of water off before the water will stop completely. then change your valve over quickly and reconnect everything, then uncap expansion, open cold feed, bleed rad, put head on and test.

Buford T Justice

Sparkpea wrote: »

nah u dont need to drain the system down, just plug it

by this I mean cap off the expansion (speedfit or compression stopend), if you've a gatevalve on your cold feed close it or again cap it off, this creates a vacuum. then close the rad valves on both sides of the rad that you're going to change the valve. what I do is disconnect the side with the trv on it and use a compression stopend to screw onto the tail of the rad to stop the water in the rad escaping. then break the seal slightly on the pipe coming into the valve just enough to let you turn the valve so that its facing you, tighten it up again. open the valve into a bucket which should drain about 2-3litres of water off before the water will stop completely. then change your valve over quickly and reconnect everything, then uncap expansion, open cold feed, bleed rad, put head on and test.

God bless the internet. This is why I love boards, one of these little nuggets that makes the word of difference, and life becomes so much easier.

Thanks Sparkpea.

PS, were this to be a closed system, is there a way to cheat out if it too? Last valve I replaced I had to drain the system when it was a closed one.

Sparkpea

if its a sealed system then I drop the pressure using the PRV, then do the same work at the rad, drain some water out through the valve etc. again wont be much water.

also I meant to mention with the plug things, it will only work if you do one pipe at a time, you cannot have more than one pipe open/cut at the same time. so if for example you where piping a new rad you should cut e.g. the flow pipe, alter it to the valve, close the valve, cut the return pipe and do the same.

this is what the plugs I talk about look like, you can get them in any wholesalers normally or diy stores, made by loads of different brands.

http://www.draytoncontrols.co.uk/DrainEasyKit.aspx

the tapered bit will push into the tank connector from within the tank if you don't have a gatevalve fitted. this will fit 15mm and 22mm tank connectors. you can also push this up the inside of a 22mm expansion and it will hold/create the vacuum. on the other end of the taper is a 15mm hole which you can use to push onto a 15mm expansion. basically these 2 plugs are all you need and are 1 of my most important tools my old man has a wee box of plugs and corks he uses, hes a plug that fits 28mm pipe but for the life of me I've not been able to find one in 8 years lol. I'll have to pinch his when he retires in a few years

Buford T Justice

Diamond. Gonna be getting me one of those.:D

Thanks mate.