My Bulldog TRVs are about 15 years old. One of them has been
fitted with an electronic control, but has stopped turning off.

Having put back the original thermostatic head, it still seems to
be stuck open, though the spindle appears to move freely.

Before the TRVs were replaced, I had regular issues with them
sticking closed, but this is a new one on me.

I wondered if a some contamination was blocking the valve
movement, and left it fully open for a while in the hope that it
might flush through, but no luck so far.

Any thoughts? I know that in a pressurised system I ought to be
able to quickly dive in and have a look once I have let the
pressure out, but I really don't want a sudden gush of black
liquid in my lounge.

Chris
--
Chris J Dixon Nottingham UK
@ChrisJDixon1

Plant amazing Acers.

Chris J Dixon wrote:
My Bulldog TRVs are about 15 years old. One of them has been
fitted with an electronic control, but has stopped turning off.

Having put back the original thermostatic head, it still seems to
be stuck open, though the spindle appears to move freely.

Before the TRVs were replaced, I had regular issues with them
sticking closed, but this is a new one on me.

I wondered if a some contamination was blocking the valve
movement, and left it fully open for a while in the hope that it
might flush through, but no luck so far.

Any thoughts? I know that in a pressurised system I ought to be
able to quickly dive in and have a look once I have let the
pressure out, but I really don't want a sudden gush of black
liquid in my lounge.

Chris


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.

Dan S. MacAbre wrote:

Chris J Dixon wrote:
My Bulldog TRVs are about 15 years old. One of them has been
fitted with an electronic control, but has stopped turning off.

Having put back the original thermostatic head, it still seems to
be stuck open, though the spindle appears to move freely.

Before the TRVs were replaced, I had regular issues with them
sticking closed, but this is a new one on me.

I wondered if a some contamination was blocking the valve
movement, and left it fully open for a while in the hope that it
might flush through, but no luck so far.

Any thoughts? I know that in a pressurised system I ought to be
able to quickly dive in and have a look once I have let the
pressure out, but I really don't want a sudden gush of black
liquid in my lounge.

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?

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

Chris
--
Chris J Dixon Nottingham UK
@ChrisJDixon1

Plant amazing Acers.

On Fri, 13 Dec 2019 10:43:38 +0000, Chris J Dixon wrote:

My Bulldog TRVs are about 15 years old. One of them has been fitted with
an electronic control, but has stopped turning off.

Having put back the original thermostatic head, it still seems to be
stuck open, though the spindle appears to move freely.

Before the TRVs were replaced, I had regular issues with them sticking
closed, but this is a new one on me.

I wondered if a some contamination was blocking the valve movement, and
left it fully open for a while in the hope that it might flush through,
but no luck so far.

Any thoughts? I know that in a pressurised system I ought to be able to
quickly dive in and have a look once I have let the pressure out, but I
really don't want a sudden gush of black liquid in my lounge.

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


--
AMD FX-6300 in GA-990X-Gaming SLI-CF running Windows 7 Pro x64

David wrote:

On Fri, 13 Dec 2019 10:43:38 +0000, Chris J Dixon wrote:

My Bulldog TRVs are about 15 years old. One of them has been fitted with
an electronic control, but has stopped turning off.

Having put back the original thermostatic head, it still seems to be
stuck open, though the spindle appears to move freely.

Before the TRVs were replaced, I had regular issues with them sticking
closed, but this is a new one on me.

I wondered if a some contamination was blocking the valve movement, and
left it fully open for a while in the hope that it might flush through,
but no luck so far.

Any thoughts? I know that in a pressurised system I ought to be able to
quickly dive in and have a look once I have let the pressure out, but I
really don't want a sudden gush of black liquid in my lounge.

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.

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
--
Chris J Dixon Nottingham UK
@ChrisJDixon1

Plant amazing Acers.

On 16/12/2019 08:23, Chris J Dixon wrote:
David wrote:

On Fri, 13 Dec 2019 10:43:38 +0000, Chris J Dixon wrote:

My Bulldog TRVs are about 15 years old. One of them has been fitted with
an electronic control, but has stopped turning off.

Having put back the original thermostatic head, it still seems to be
stuck open, though the spindle appears to move freely.

Before the TRVs were replaced, I had regular issues with them sticking
closed, but this is a new one on me.

I wondered if a some contamination was blocking the valve movement, and
left it fully open for a while in the hope that it might flush through,
but no luck so far.

Any thoughts? I know that in a pressurised system I ought to be able to
quickly dive in and have a look once I have let the pressure out, but I
really don't want a sudden gush of black liquid in my lounge.

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.

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).

John wrote:

Do you had a "Decorators" cap to fit - this holds the pin down. See if that
stops the flow.

I'm giving this a try right now.

Also make sure the head has dropped into its seating (Hex).

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

Chris
--
Chris J Dixon Nottingham UK
@ChrisJDixon1

Plant amazing Acers.

On Mon, 16 Dec 2019 08:23:26 +0000, Chris J Dixon wrote:

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

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

https://youtu.be/73PhujkQuyEY

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



Thomas Prufer

Thomas Prufer wrote:

It is sometimes possible to change the innards without drips and mess, i.e.
https://youtu.be/73PhujkQuyEY

clever

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

£300 for the base tool (plus adapters for each valve type?)

https://www.hlkshop.ch/de/imi-hydronic-engineering-montagegerat-artnr-9721-00000

On Tue, 17 Dec 2019 08:01:56 +0000, Andy Burns wrote:

£300 for the base tool (plus adapters for each valve type?)

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

On 16/12/2019 09:25, Robert wrote:
On 16/12/2019 08:23, Chris J Dixon wrote:
David wrote:

On Fri, 13 Dec 2019 10:43:38 +0000, Chris J Dixon wrote:

My Bulldog TRVs are about 15 years old. One of them has been fitted
with
an electronic control, but has stopped turning off.

Having put back the original thermostatic head, it still seems to be
stuck open, though the spindle appears to move freely.

Before the TRVs were replaced, I had regular issues with them sticking
closed, but this is a new one on me.

I wondered if a some contamination was blocking the valve movement, and
left it fully open for a while in the hope that it might flush through,
but no luck so far.

Any thoughts? I know that in a pressurised system I ought to be able to
quickly dive in and have a look once I have let the pressure out, but I
really don't want a sudden gush of black liquid in my lounge.

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) butÂ* 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.


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.