New Drayton rad valves leaking. Faulty or not?

[Agile]

I am also a bit confused when you talk about a plumber fitting the rad valves and then its YOU who find the caps and fit them.

If you do not have the rubber seals for the caps then you can cut them from a bit of old inner tube which any tyre place would give you if you ask nicely.

Tony

 

[Aquaheat]

Also note that your trv's aren't actually in the off position they are in the frost protection position. If the room is cold then they will allow water to pass. You should have plain white decorators caps that replace the trv head and allow full shut off although as above this shouldn't be relied upon and they should be capped off as a precaution.

 

[mfarrow]

From reading through the initial post it sounds like the plumber put the white decorators caps on the top where the TRV should be, but these were leaking through slightly. They are designed to apply pressure to the pin underneath to 'virtually' cut off the flow completely. The TRVs are not designed to cut off flow completely, even in the lowest * setting they will leak through as soon as the house gets cold-ish.

I say 'virtually' because the decorators caps might have been OK but you've now got the belt & braces approach of adding a brass cap where the radiator tail should be. Good job.

Now put the decorators caps back on where the TRV is to stop the TRVs getting mucked up.

Unless the TRV is definitely leaking from underneath then the original plumber hasn't done anything wrong except being too reliant on the decorators cap by not adding a brass cap for a belt & braces approach.

 

[Mr. Clueless]

I've been out most of the day so i'm just getting back to you guys.

Agile - sorry buddy. I did read but what i am really wanting to avoid is a situation where we basically say to this guy - "look, we listened to what you said & we didn't like it, so we're not going to go on your advice & just crack on & fit the bloody thing can you". Obviously a bit more polite than that but you get my drift.
But yes, a plumber fitted the rad valves but he didn't fit any brass caps. It was I who did that this morning. He just put the decorators cap on which then leaked when i pressurised the system & then he took this off & put the TRV on ... no brass cap.
But i think we'll just tell the guy that once we put a cap on it solved the problem (so far at least). So just carry on with the existing valves.

Aquaheat - Yes i noticed that the TRVs are in the frost [*] setting however when i try to turn them down further, they don't budge, neither of them. This appears to be their lowest setting. Though i'll try on the one that's actually connected to a radiator & see if that's the same.

mfarrow - yes you got it in one. That's what he did. Though when the decorators cap leaked, i've no idea as to how much. Whether it was a dribble or whether it was gushing out as i was upstairs.


Everyone - I've been out today, i've had the windows open a little to help the plaster dry out, so inside has got a bit chilly. Radiator control thingy on the wall said 11c. The boiler was 1.5bar before i left. I bled the system. Came back, noticed the plumb tray thing was still bone dry. Closed windows, turned heating on, wife had a shower, had something to eat, checked plumb tray again - still bone dry. Boiler still 1.5bar.


So fingers crossed all that it was was a brass cap that was needed.

 

[FiremanT]

Aquaheat - Yes i noticed that the TRVs are in the frost [*] setting however when i try to turn them down further, they don't budge, neither of them. This appears to be their lowest setting.

That IS the lowest setting. The TRVs sound fine

 

[mfarrow]

Our TRV4s open by 10 degrees. They are not suited to keeping the output closed, Honeywell supply the cap to do that, but as discussed it has limitations.

However, I just drained down our upstairs pipes (not inc. radiators) over the weekend to fix a leak in the kitchen, using the caps suppied with the TRVs, and the pipe stayed dry. I've also had the rads off for plastering for a week or two before. I put caps over the tail but underneath has been dry when finished.

I'm either very lucky with my 7 or you've been unlucky with your two.

 

[Mr. Clueless]

Yeah just to confirm - i tried the one that's been connected to a rad & the [*] setting really is the lowest it can go. Other TRVs in the house have a 0 after the [*] (different brands) but not these Drayton ones.

Anyway i took the TRV off the one in the hall & fitted the decorators cap - no bother.

Took the TRV off the one in the living room & wouldn't you know it - water peeing out. Good job i was wearing the marigolds else i'd have burnt myself. It only peed out so much & then i was able to get the decorators cap on that one too.

Gave the job a wipe up, put the bowl back under it & will see again in the morning.

 

[Bunnyman]

See this happen a lot but not usually where a skilled plumber is involved. Basically trvs on the star frost setting will hold pressure but as the area cools they will open automatically and leak, usually use the decorator caps and the compression cap as belt and braces

 

[Mr. Clueless]

Why do these TRVs not have a 0 setting then?

I've no idea what brand TRV is on the other rad in the living room but it's not a Drayton one & it has a 0 setting ............. and it's remained bone dry whilst all this is going on.

I would've thought the frost setting would kick in ... when things start getting frosty. 11c on the display thing on the wall isn't frosty to me. Clearly there's more to it than that but i didn't expect it to kick in at that display temp.

 

[Bunnyman]

Well they do

 

[dilalio]

The bottom line here really is that plumbers "know" they let by, so we cap them!

 

[Mr. Clueless]

Well I had a check before I went to bed last night & there was no drop in pressure all day. Approx 1.25bar ish.

Check this morning - bowls & trays bone dry. TRVs dry except for a bit of condensation around them but nowhere a leak would get to really.

Check boiler again ... About 0.75bar.

Why is it dropping pressure & not leaking? Or at least seemingly not leaking.

Didn't happen (pressure drop) before the weekend.

 

[Aquaheat]

Aquaheat - Yes i noticed that the TRVs are in the frost [*] setting however when i try to turn them down further, they don't budge, neither of them. This appears to be their lowest setting.

That IS the lowest setting. The TRVs sound fine

My apologies if my post lead you to believe they would go lower. That wasn't what I meant hence why I said that the decorators caps will allow FULL shut off. TRV4's only have a frost setting as a minimum that activate at around 10C if i remember correctly.

Jon

 

[Aquaheat]

Well I had a check before I went to bed last night & there was no drop in pressure all day. Approx 1.25bar ish.

Check this morning - bowls & trays bone dry. TRVs dry except for a bit of condensation around them but nowhere a leak would get to really.

Check boiler again ... About 0.75bar.

Why is it dropping pressure & not leaking? Or at least seemingly not leaking.

Didn't happen (pressure drop) before the weekend.

Possible air in the system being released via the auto air vent. Top back up again and let the system settle. If it is continuing to do this after a day or so then it needs further investigation. Also be aware that as you have topped the system up quite a few times recently you would be best off adding or topping your inhibitor level as if its left you will promote corrosion in the system.

Jon

 

[Mr. Clueless]

Thanks for that. Ill check for air again tonight.

Regards inhibitor - the plumber is out on Thursday morning so I rightly/wrongly (hopefully rightly) thought it'd be ok for just 4 days.