Help with radiator valve

[Coldandclueless]

Hello, a second query, this one about a normal radiator. All my other radiators have a thermostatic control at one end and a valve at the other which you just turn all the way to the left for on and all the way to the right for off. I understand these! I have one in the loft which has been cold for ages. I want to check it is actually on. The pin is up under the thermostatic valve so that end is ok. The other end has a cap, and under the cap it looks like the photo attached. Am I meant to turn that with pliers to make sure it is on??

 

[JCplumb]

Yes.
Lockshields can come with either a decorative cap (like this one) or a valve handle (like your others). The actual brass bit is the same and just needs turning to operate, either by the handle provided or pliers/adjustables etc.

 

[Pickwickpick]

If this radiator used to work and you've never messed around with the lockshield valve, it won't be closed. If its only partially open and opening it up fully allows this rad to warm up, then you're going to need to balance your system properly, there's a good guide pinned to the top of the central heating forum if this does not doing.



How well did the rad work when it was initially installed and how long did it work for?

 

[Coldandclueless]

It was installed about three years ago and it worked well, I don't know when it stopped but it hasn't worked this winter. Well, after bleeding the radiator (a bit of air), making sure the valve pin moves freely, turning all other radiators off and banging the pipe with a spanner, it is now getting luke warm at the top and less warm but not cold at the bottom. Can it be sludge in a three year old radiator? I checked the lockshield valve as described above and it was almost fully open.

 

[Pickwickpick]

Yes it could be sludge causing a blockage, based on your description in your towel rad thread it sounds like the pipework is blocked not necessarily the rads. You said that both pipes were cold with the towel rad, was that the same with this rad (before you managed to get them luke warm)?

Few other questions:

Did they flush the system out when they fitted the new rads? How old is the rest of the system? Have you got a magnetic filter of some sorts on the central heating system? What type of boiler do you have? From that picture it looks like microbore, i.e. 8 or 10mm pipe, is that the case and if so is that for all the radiators or just the new ones?

 

[Burger]

It was installed about three years ago and it worked well, I don't know when it stopped but it hasn't worked this winter. Well, after bleeding the radiator (a bit of air), making sure the valve pin moves freely, turning all other radiators off and banging the pipe with a spanner, it is now getting luke warm at the top and less warm but not cold at the bottom. Can it be sludge in a three year old radiator? I checked the lockshield valve as described above and it was almost fully open.

Sludge can occur quickly, especially if they drained down, taking out the inhibitor (protection) and not adding any back in, therefore diluting the original inhibitor. Also any other venting.

 

[Coldandclueless]

Its a new Worcester Bosch boiler fitted a year ago and it has a magnetic filter. They are coming to service it next week. I don't know if the whole system was flushed when the radiator was fitted, we had lots of work done at the same time, I know they flushed out two old radiators downstairs. I have been told the pipework looks too small, all the radiator pipes look the same size to me.

 

[Coldandclueless]

Sorry missed a question, the pipe to the radiator was warm before I did all my DIY attempts!

 

[Aire]

10mm microbore and a radiator that used to work but now doesn't. I'm thinking blockage.

 

[Pickwickpick]

Does sound like a blockage, microbore is particularly prone to it. You could try getting some cleaner in there (Sentinel X400 or Fernox F3). If you do, don't forgot to dose the cleaned system with some inhibitor.

 

[AMGasServices]

Is your house a new build?

Although there may be some form of restriction in the pipework. I am of the opinion there is probably a kink in the pipework behind the radiator. (Been a few radiator not heating up in new builds and 10mm pipework. They described the same symptoms as you have).

I’d advise to isolate the radiator from both ends, drain the radiator down, remove it and check for kinks in the pipes.

 

[Pickwickpick]

Is your house a new build?

Although there may be some form of restriction in the pipework. I am of the opinion there is probably a kink in the pipework behind the radiator. (Been a few radiator not heating up in new builds and 10mm pipework. They described the same symptoms as you have).

I’d advise to isolate the radiator from both ends, drain the radiator down, remove it and check for kinks in the pipes.

This isn't the only rad that's not working, they've also got a towel rad in the bathroom that's not working (OP has created a separate thread for the other one). Both were installed at the same time and unlike this one the bathroom rad has a cold flow pipe. Could be a kink somewhere, its microbore so its easier to kink, but with both having gone at different times (iirc) I'm leaning more towards a blockage.

Definitely worth checking over any accessible pipework, but if all accessible pipework is ok, I'd try a cleaner first as the least destructive/expensive first port of call.

 

[sammathias]

I haven't read everyone's posts but if it's not full of air and you have a pressure above 1 bar in boiler then it will more than likely just be an airlock in the pipework. Run heating flatout and turn off most of the other radiator trvs...this should force water to the problem rad and remove airlock.

 

[Coldandclueless]

Thank you all for replies. I tried turning off everything else and managed to get this radiator to heat up! So I guess its a balance issue?

 

[sammathias]

Probably just an airlock in the pipework.