[SOLVED] Sticking Thermostatic Radiator Valves

[Milleniumaire]

The central heating system in the house that I bought as new 5 years ago is fitted with Pegler Terrier II thermostatic radiator valves. About a year ago I noticed that on a couple of radiators even when the valve was turned off (* setting) the radiator remained hot so I assumed the valve had failed and replaced both valves. Having just drained the system and refilled it with Fernox cleaner I have noticed that another 3 radiators are staying hot when the heating is on regardless of whether the valve is turned off or not! It seems that the small pin is not being pushed down by the head. I have tried swapping the heads with heads from other radiators which are working okay but this doesn't seem to make any difference. This confuses me as I thought the problem was in the head not in the valve (the part connected to the radiator).

Can anyone explain how these valves work and what is going wrong? Is there any way of repairing them or do they need to be changed? Have I got a bad make and need to switch all the valves before they continue to fail (I would rather resolve the problem in one attempt rather than spend the next 5 years having to change individual valves as they fail).

Thanks in advance for your advice.

Regards. Paul.

[Set Square]

Have you tried removing the heads and pressing the pins down manually? This should unstick them if they are stuck. The bellows in the TRV can't exert as much force as you can! Many of these valves are supplied with an alternative (manual) head - for turning the valve off positively when decorating etc. Have you got any of these? If so, what happens when you fit one and screw it down?

[Milleniumaire]

Pressing the pins down seems to have loosened them up and they are "currently" working but I suspect it is just a matter of time before they stick again!

Thanks.

Paul.

[chris French]

In message , Milleniumaire writes

When you finally get fed up with them, ditch them and replace them with Drayton TRV4s ' in a recent survey, 8 out of 10 uk.d-i-y'ers said they preferred the taste'

[Milleniumaire]

I have been liaising with somebody at Pegler via email about my problem with sticking pins and they tell me that "The Pegler Terrier II has never sufferred from this problem". So there you have it - from the horses mouth. I must be "imagining" that 5 out of the 16 Pegler Terrier II TRV's fitted to my radiators are failing to open or close because the pins in the valves are sticking! I have noticed that in each of these valves there is a hint of leakage so I suspect that rust/limescale is causing the pins to stick.

I will be replacing the valves with a different make to ensure that I don't "imagine" this problem again.

Paul.

[Gromit]

replying to Milleniumaire, Gromit wrote: I know this is an old thread, but I fitted the same TRVs in my brand new installation in 2006 and within 3 years eight out of 11 had failed - they do not turn off even with the 'decorating head' fitted (a simple screw cap that you use to turn it off for radiator removal when decorating). I managed to get Pegler to send me five replacements and fitted them, but now ALL of them (original and replacements) have failed. I cannot believe this, as Pegler are supposed to be high quality, and I've had them from batches three years apart. My system was all-new throughout and was flushed and inhibited with Sentinel products so the TRVs have had the best environment to work in (or in this case not work in!).

When I get the time and energy I will be replacing all 11 TRVs with Drayton TRV4s which I used in my previous house and only had one head failure but no valve body failures. I guess Pegler have been resting on their reputation for too long now, along with the likes of MK etc. Once fine British companies, but no more.

[Andrew Gabriel]

I vaguely recall one of the manufacturers' TRVs (might have been Pegler) turned out to be incompatible with inhibitor. Another poster here got them all replaced for free due to this.

[Andy Bennet]

Take off the thermostatic head, slacken the inner brass nut half a turn, depress the pin a few times to make sure free, tighten up nut, replace head. Job done.

Works on all my Peglar TRV's.

[DerbyBorn]

Surely if they are not turning off with the decorator cap it implies the rubber washer has disintigrated.

[Andy Bennet]

No, not at all. If the pin is stuck (which most of mine have at some point) then no amount of reasonable force seems to free it. But just relaesing the inner nut half a turn always does free it - don't know why. Having freed the pin and applied a bit of WD40 never had the problem again on the same valve. just giving you my experience with Peglar TRV's.

[DerbyBorn]

I would have thought the decorators cap - to screw down, must be depressing the plunger all the way as that is its role. If the plunger is right down then why wouldn't it turn off?

[Andy Bennet]

That's the problem - the pin gets stuck mid travel - not when it is closed, hence putting the decorators cap and tightening as much as possible will not shift it. I do not know why they stick at a partially open to fully open position, but 6 (out of 14) of my Peglar (Terrier) TRVs have done that so far - I installed them around 5 years ago.

[DerbyBorn]

Ah!

[kenned]

replying to Andy Bennet, kenned wrote: Tried your "inner nut half turn" advice on my Pegler TRV. Worked first shot. No need to drain down system - was a bit worried about water going everywhere but this operation was performed without seeing a single drop.

[Alicia Weston]

replying to Milleniumaire, Alicia Weston wrote: Yeah I have about 10 of the damn things and I have had the same problem with about 4 of them. Very disappointed with the quality

[Dave. A.]

replying to Andy Bennet, Dave. A. wrote: Good advice Andy, works a treat. Thank you.

[Dave. A.]

replying to Andy Bennet, Dave. A. wrote: Good advice Andy, works a treat. Thank you.

[Brian Gaff]

Whenever you have to reply via this broken interface, always cut and past the reply as as well as not caring what year it is it breaks the trhead as well. brian

[TSP]

replying to Andy Bennet, TSP wrote: That worked a treat. Thanks so much Andy Bennett. Perfect advice to easily resolve Pegler TRV with pin stuck fully open. I?ve tried searching all over, and no one else gave this advice. So simple.

[Brian Gaff]

Now all we need is to fix Home owners club usenet interface to quote the post people reply to and sort their messages by year not just month and life might be more bearable... :-)

Brian