How does radiator whose inlet and outlet are on the same side works and how to shutdown to change broken valve?

[araknafobia]

Hello all,
I am not very good at the terminology so I will try to show images as much as possible.
I am living in a one floor apartment and I have this radiator whose is always on. I found that valve pin doesn't work anymore. I can move the pin in and out but it doesn't change the water flow. This is the valve that doesn't work (I am referring to valve (kind of T shaped) itself not the thermostatic valve).

I decided to change the valve with a new one. However, I don't know how to stop water coming to radiator to safely change the valve. The part that baffles me is that I have a radiator whose inlet and outlet on the same side like this;

I also have these pipes coming out of the CV. I have 7 radiators and I have 7 pairs of red and blue (cold and warm) pair of pipes coming out of the boiler. I am not sure if they would play a role in stopping the water flow.

What I read and gathered on the internet so far is this;
- Changing valve (not just the thermostatic valve but the valve itself ) easy as long as I make sure that they system is closed and no water is flowing.
- Before I start I will need to shut off the CV completely - power off basically.
- I need to stop water flow (I guess) to prevent water flood everywhere while I am changing the valve. This is the part that I am not completely sure and need help with my current setup.

Please let me know if you need more information.

Thanks in advance!

 

[Madrab]

Where are you, not seen that type of fitting for a rad here in the UK.

You have a manifold (pic 2) that supplies the pipework to the radiators and a dual type splitter valve in the bottom of the rad that merges the flow and return into one location.

Looking at the bottom valve there will be a way to isolate the rad in that, take the screw end cap off and you'll find a turn down screw in there, I would presume that will shut off that valve and allow the nut to be loosened and the rad to be drained down a little. If you are changing the top valve you will only need to release the pressure and drain a little water out (drain valve bottom right) and then the valve can be removed.

You say the TRV doesn't shut the rad off, how do you know? Do you have a decorators cap where you can remove the TRV head and then compress the pin on the valve properly for a period of time to see if it then cools down. I would suspect the TRV head more than the valve itself.

 

[fixitflav]

Where are you, not seen that type of fitting for a rad here in the UK.

Netherlands. Hover over the flag and it tells you.

 

[araknafobia]

Hi @Madrab thanks for taking time to reply!

Where are you, not seen that type of fitting for a rad here in the UK.

I am in Netherlands but I am an expat so that's why I am asking in English forum I also never seen anything like this in Netherlands.

Looking at the bottom valve there will be a way to isolate the rad in that, take the screw end cap off and you'll find a turn down screw in there, I would presume that will shut off that valve and allow the nut to be loosened and the rad to be drained down a little. If you are changing the top valve you will only need to release the pressure and drain a little water out (drain valve bottom right) and then the valve can be removed.

I am only changing the top valve. I will give this a try to tomorrow. I will report back with result/findings.

You say the TRV doesn't shut the rad off, how do you know? Do you have a decorators cap where you can remove the TRV head and then compress the pin on the valve properly for a period of time to see if it then cools down. I would suspect the TRV head more than the valve itself.

Sorry if that wasn't clear. I already removed the TRV and played with the pin. I can move the pin in and out but it has no effect on water flow. That's why I am planning to change the valve that has a pin on it because I think it's just not working anymore. I hope it's clear now

 

[Madrab]

I can move the pin in and out but it has no effect on water flow.

Ah ok, I presume you tested it? You would need to push the pin in and wait for 10-15mins to see if the pipework/rad cools down any, you wouldn't get an instant result.

 

[araknafobia]

Ah ok, I presume you tested it? You would need to push the pin in and wait for 10-15mins to see if the pipework/rad cools down any, you wouldn't get an instant result.

@Madrab Yes, I tested it. I am sorry I keep forgetting certain details. When I push the pin in, it stays there - it suppose to come back as soon as I stop pushing. When the pin is pushed-in state, it should stop water flow and it doesn't. I waited more than 30 minutes or so and radiator was still warm as usual (warm = kind of half warm - this radiator is always half warm - I do think that under the hood pin mechanism is stuck mid-way)
Thanks for double checking and asking for clarification. I do really appreciate it.

 

[araknafobia]

Hi @Madrab, I just did take a look at the left side of the `dual type splitter valve` and this is what I found;
First, I took the screw cap off (I was actually afraid that water is going to come out as soon as I open this "cap" );

Then I saw a small screw there - I hope you can see in the picture as well:

Then I did a small experiment. I turned on the CV system, top valve is always half on anyway (that's why I want to change it) so water flow was also on and then;
- Turned that small screw all the way to left and waited 1 hour to see if radiator gets any colder. It didn't.
- Turned that small screw all the way to right and waited 1 hour to see if radiator gets any colder. It didn't.
NOTE: With `small screw` I refer to "inner golden circle" in not "outer big circle".
Do you think what I did make sense? Should I have seen a different result? What would you suggest I should try next?
Thanks in advance!

 

[Madrab]

That allan key'd brass centre section should shut off the valve completely at some point in its travel, otherwise there would be no need for it. Is there a makers name on the top of the TRV valve? What are those initials on the side of the lower valve?

 

[araknafobia]

Hi @Madrab sorry I was sick for few days and couldn't answer.

That allan key'd brass centre section should shut off the valve completely at some point in its travel, otherwise there would be no need for it.

That's what I was hoping but didn't make any difference.

Is there a makers name on the top of the TRV valve? What are those initials on the side of the lower valve?

I took this pictures. I hope these are what you are looking for. Let me know if you need more information. And as always. Thanks for taking time to reply!