Woke to a wet patch under a TRV - potential cause and possible fix?

BooJewels

Evening.  A totally lovely man came from Dyno Rod, who must be subcontractors for more plumbing type work, rather than gas work.  He has had a good look at the bottom of the radiator, inside the TRV and the various connections. 

He thought that the incident/leak was a combination of factors - a significant pocket of trapped air, a cold night, two areas that weren't as tight as they could have been, resulting in additional pressure that broke through one of these less-tight connections.

The two he tightened were the nut below the TRV, which he said was quite loose and the bleed nut at the top.  He said what often happens is that when you bleed a rad until water runs, the water can be gritty and deposit bits in the seat of that valve, making it tight enough when it's hot and enough to stop the water as you do the bleeding, but once cold, can leave a potentially leak-able gap.  But he felt that the likely culprit was probably the loose nut under the TRV.  The TRV he said was in good nick, working well - nothing needed replacing.

He thought it was possible that the significant volume of air had been maybe trapped elsewhere - perhaps even since the new boiler was started - without impacting on the efficacy of the system, but it had moved and accumulated in this one rad for some reason yesterday.

There hasn't been any further leakage since I bled it and topped up the boiler pressure (or air gurgling) and he was confident that it was a one-off incident due to an accumulation of small factors - like many incidents turn out to be.  I shall still wrap an old towel around the bottom of the pipes tonight. Just in case.  I will however have to try and get the stains out of the carpet.

Thank you for your moral support today, it truly was a help to me.  Even though I think of myself as hopefully more capable than most with practical things, I'm on a very steep learning curve since my husband passed away and I'm also sure that more things than usual have seemingly gone wrong recently.  But every day is a school day and I have to see each incident as a learning opportunity.  At least I now know how to re-pressurise the boiler.  Tomorrow I'm going to learn how to use a critter sander and re-cover some old drawers with vinyl.    

BooJewels

Unfortunately, that's not fixed it.  The paper and towels I wrapped round it overnight are sodden this morning.

What I'll do, is switch the heating off tomorrow morning until I've got up and I'll try and see where it's leaking from before I call them back.

Bendy_House

Ah, shame, Boo.

Everything the guy said seems fair enough, and he was thorough in explaining it all to you - kudos to Dyna in this case. Let's hope the air issue is as he suggested - there from the boiler swap, so will diminish soon.

Good luck with locating the leak tomorrow.

Did the guy remove the TRV head to expose the 'pin' underneath? I'd do that, too, before going to bed, so that any leak from there is immediately obvious in t'morn.

Ok, you have 4 storeys? Which floors have rads on them? On which floor is the boiler located? And what do your boiler pressure readings say - when cold, after in use for some time, etc?

daivid

Which pipe(s) was/were the towel(s) wrapped around? Which bits of towel were wet? My initial thought on seeing your photo was that the mating between the pipe coming up from the floor and the trv may be far from optimal (is everything in line? was the pipe cleaned properly? has the pipe been compressed at some point?). Was this checked by the man from dynorod?

BooJewels

I'll answer you both in turn, as there were a lot of questions.

Bendy_House said:

Ah, shame, Boo.

Everything the guy said seems fair enough, and he was thorough in explaining it all to you - kudos to Dyna in this case. Let's hope the air issue is as he suggested - there from the boiler swap, so will diminish soon.

Good luck with locating the leak tomorrow.

Did the guy remove the TRV head to expose the 'pin' underneath? I'd do that, too, before going to bed, so that any leak from there is immediately obvious in t'morn.

Ok, you have 4 storeys? Which floors have rads on them? On which floor is the boiler located? And what do your boiler pressure readings say - when cold, after in use for some time, etc?

I haven't heard any more air in the system since, so I hope that is now sorted. I kept bleeding it periodically yesterday until the sounds stopped and I only got water from the bleed nut, no hissing.

Yes, he removed the TRV head and said the pin was working fine (I actually asked him), nothing stuck and no need to replace.  I'll take that off tonight too.

Four storeys - two living ones, with a cellar and an attic room with stairs up.  Rads on the 2 middle floors; 7 in total - boiler and 3 rads on the ground floor, 4 rads upstairs.  GCH doesn't serve either the cellar or top bedroom.

I need to figure out how to show the pressure readings, if it's even possible, the manual doesn't cover it.  I suspect it's one of those things that you have to go into 'service' mode for.   It has a graphic display, with a couple of dotted lines to show the ideal range and every time I've looked at it, it's been bang in the middle of that.  It was fractionally above the middle when I filled it yesterday and once I fired the heating up and it started circulating, the level dropped a smidge and it has been in the same place since.  I didn't look at it when cold overnight, sorry.  I'll look in the morning before I fire it up again.

BooJewels

daivid said:

Which pipe(s) was/were the towel(s) wrapped around? Which bits of towel were wet? My initial thought on seeing your photo was that the mating between the pipe coming up from the floor and the trv may be far from optimal (is everything in line? was the pipe cleaned properly? has the pipe been compressed at some point?). Was this checked by the man from dynorod?

I wrapped kitchen paper around the 3 branches of the T of the valve connections, thinking that if there was a small leak, the piece of paper that was wet would indicate where it was.   The towel was bunched around the pipe going into the floor, beneath the papers, just to protect the carpet.  Unfortunately, everything was sodden and the papers had sagged, so it wasn't obvious where the epicentre of the leak was.  All of the towel was soaked, I held it up and looked at it.  The carpet underneath was damp again too.

It was the nut underneath the TRV connecting it to the pipe coming up through the floor that he tightened quite a bit and he thought was the culprit.  I don't think he took anything apart further than taking the top off the TRV, as finding a loose nut he thought was the fix.

This radiator has been in place since the 70s he said - we moved in in 1988.  I think the TRV was added when we had the last boiler installed just over 20 years ago.  It hasn't been touched or any joints loosened or moved since then.  So if it's wonky, it's been wonky for a long time and if it's been compressed, it's been that way for a long time.  I don't know how carefully he checked as I wasn't watching him as the valve is right behind the door, so I left him to it until he called me in to have a look.  Surely checking connections like that would require draining the system?

Bendy_House

BooJewels said:

I haven't heard any more air in the system since, so I hope that is now sorted. I kept bleeding it periodically yesterday until the sounds stopped and I only got water from the bleed nut, no hissing.

Yes, he removed the TRV head and said the pin was working fine (I actually asked him), nothing stuck and no need to replace.  I'll take that off tonight too.

Four storeys - two living ones, with a cellar and an attic room with stairs up.  Rads on the 2 middle floors; 7 in total - boiler and 3 rads on the ground floor, 4 rads upstairs.  GCH doesn't serve either the cellar or top bedroom.

I need to figure out how to show the pressure readings, if it's even possible, the manual doesn't cover it.  I suspect it's one of those things that you have to go into 'service' mode for.   It has a graphic display, with a couple of dotted lines to show the ideal range and every time I've looked at it, it's been bang in the middle of that.  It was fractionally above the middle when I filled it yesterday and once I fired the heating up and it started circulating, the level dropped a smidge and it has been in the same place since.  I didn't look at it when cold overnight, sorry.  I'll look in the morning before I fire it up again.

Yes, the standard display shows a bar graph, with the min being ~1bar and the max, ~2bar. It seems it might change to actual pressure readings if you press the rectangular-symbol-which-loooks-like-a-TV-with-a-solid-rectangular-block-in-the-bottom-right-hand-corner button twice...

The reason I asked about 'storeys' is that a boiler on a ground floor with a few stories above it might require a higher pressure in order to maintain that pressure in the highest rads, with the risk of that pressure dropping to below atmospheric at times, and sucking in air. But this won't apply to you since you effectively only have two levels going on, and any pressure over 'min' should therefore be fine.

Anyhoo, we look forward to your report tomorrow! That TRV pin is surrounded by a brass nut, so if you find the water is coming up around there, then that'll need the 'tweak'. But, let's see what tomorrow brings. (You do understand that if you report back that there's a puddle, but that you cannot find the source, we will have to track you down...)

4.12 Guaranteeing the correct
filling pressure of the heating
system
4.12.1 Checking the filling pressure
of the heating installation
Note
To ensure that the heating installa-
tion operates smoothly, the filling
pressure when the heating install-
ation is cold must be between
0.10 MPa and 0.20 MPa (1.0 bar
and 2.0 bar) or lie between the
two dashed lines in the bar graph
display.
If the heating installation extends
over several storeys, a higher filling
pressure may be required for the
heating installation. Ask a compet-
ent person for details.
In addition, the symbol appears
after approx. one minute.
If the filling pressure in the heating
installation falls below 0.05 MPa
(0.5 bar), then the product switches
off. The display alternates between
the fault message F.22 and the
current filling pressure.
1. Press twice.
◁ The values for the current filling
pressure and for the minimum and
maximum filling pressures appear in
the display.
2. Check the filling pressure in the
display.
1 / 2
System pressure: 0.10 ... 0.20 MPa
(1.00 ... 2.00 bar)
The filling pressure is in the intended
pressure range.
2 / 2
Filling pressure: < 0.08 MPa
(< 0.80 bar)Operation 4
0020230532_03 ecoFIT pure Operating instructions 13
▶ Fill the heating installation.
(→ Page 13)
◁ If you have topped up the install-
ation with sufficient

daivid

BooJewels said:

This radiator has been in place since the 70s he said - we moved in in 1988.  I think the TRV was added when we had the last boiler installed just over 20 years ago.  It hasn't been touched or any joints loosened or moved since then.  So if it's wonky, it's been wonky for a long time and if it's been compressed, it's been that way for a long time.  I don't know how carefully he checked as I wasn't watching him as the valve is right behind the door, so I left him to it until he called me in to have a look.  Surely checking connections like that would require draining the system?

If it's all been left untouched it does make it far less likely, also all the tissue and towel being soaked suggests a leak higher up, and quite a significant one too. If it's enough to soak the floor overnight I wonder if the leak may be visible or audible when the pressure to/in the radiator is at its highest.

BooJewels

Bendy_House said:

BooJewels said:

I haven't heard any more air in the system since, so I hope that is now sorted. I kept bleeding it periodically yesterday until the sounds stopped and I only got water from the bleed nut, no hissing.

Yes, he removed the TRV head and said the pin was working fine (I actually asked him), nothing stuck and no need to replace.  I'll take that off tonight too.

Four storeys - two living ones, with a cellar and an attic room with stairs up.  Rads on the 2 middle floors; 7 in total - boiler and 3 rads on the ground floor, 4 rads upstairs.  GCH doesn't serve either the cellar or top bedroom.

I need to figure out how to show the pressure readings, if it's even possible, the manual doesn't cover it.  I suspect it's one of those things that you have to go into 'service' mode for.   It has a graphic display, with a couple of dotted lines to show the ideal range and every time I've looked at it, it's been bang in the middle of that.  It was fractionally above the middle when I filled it yesterday and once I fired the heating up and it started circulating, the level dropped a smidge and it has been in the same place since.  I didn't look at it when cold overnight, sorry.  I'll look in the morning before I fire it up again.

Yes, the standard display shows a bar graph, with the min being ~1bar and the max, ~2bar. It seems it might change to actual pressure readings if you press the rectangular-symbol-which-loooks-like-a-TV-with-a-solid-rectangular-block-in-the-bottom-right-hand-corner button twice...

The reason I asked about 'storeys' is that a boiler on a ground floor with a few stories above it might require a higher pressure in order to maintain that pressure in the highest rads, with the risk of that pressure dropping to below atmospheric at times, and sucking in air. But this won't apply to you since you effectively only have two levels going on, and any pressure over 'min' should therefore be fine.

Anyhoo, we look forward to your report tomorrow! That TRV pin is surrounded by a brass nut, so if you find the water is coming up around there, then that'll need the 'tweak'. But, let's see what tomorrow brings. (You do understand that if you report back that there's a puddle, but that you cannot find the source, we will have to track you down...)

Thank you.  I found the pdf of the installation manual myself last night, as it's easier to search than the paper copy.  I too read about the storeys, but as you say, not relevant to my issue in this instance.  Looking back I see that I posted that I had 4 storeys, but only 2 served by the GCH - I hadn't got the relevance until I read the manual - had the boiler been in the cellar, serving the 2 floors above it, it might need greater pressure.  Sorry, I answered the question without realising what was pertinent.

I had also read somewhere that the lines on the graphic were at 0.5 bar and 3 bar - but not sure where.  When I do hit that top right button twice (need to do it reasonably slowly), it does indeed show the pressure as a reading (thank you) and it's currently 1.8 bar and this would tally with being visibly about halfway between 0.5 and 3 - as it looks in the display.  In fact under the pressure number  it says something like 0,5 bar ~ 3,0 bar.   If the dotted lines were at 1 and 2, it would show as nearer 2 than it does.  Yet Vaillant themselves on their site say that it is optimal around 1.5 bar, which should be half way between the dotted lines.  So I'm a tad confused.

BooJewels

daivid said:

BooJewels said:

This radiator has been in place since the 70s he said - we moved in in 1988.  I think the TRV was added when we had the last boiler installed just over 20 years ago.  It hasn't been touched or any joints loosened or moved since then.  So if it's wonky, it's been wonky for a long time and if it's been compressed, it's been that way for a long time.  I don't know how carefully he checked as I wasn't watching him as the valve is right behind the door, so I left him to it until he called me in to have a look.  Surely checking connections like that would require draining the system?

If it's all been left untouched it does make it far less likely, also all the tissue and towel being soaked suggests a leak higher up, and quite a significant one too. If it's enough to soak the floor overnight I wonder if the leak may be visible or audible when the pressure to/in the radiator is at its highest.

Sorry, I'd meant to come back on this - looking at the photo I can see that it looks a bit bendy - but I think that's perhaps photo barrelling - I held a steel ruler lined up against the vertical slots in the TRV top plastic bit and moved my head so that the painted copper pipe below was against the ruler edge visually and it all looks like a straight line - repeated it around the pipes in different positions.  So by eye, they do look perpendicular and in-line.

I'll set my alarm to get up earlier tomorrow to check it out when it's been cold for a while - it's simply not doing anything whilst the heating is on and all of the components are warm.  I do keep running my fingers around all the edges to see if anything feels wet - but no further water escape since I got up.