Cold Radiator

housebuyer143

Can anyone advise how to fix this please? 

My kitchen radiator was cold today. I checked the TRV and it's working fine so I turned off all the radiators in case there was an air lock and the radiator comes on fine. Then I turn the radiators back on and it goes cold again. 

Obviously I can't leave the rest off but I need this radiator working as it's cold in the kitchen.

FlorayG

Gas or electric? Water based whole house system? Don't assume people know what system you have

roddydogs

If you've got TVRs they often stick.

nofoollikeold

I suspect you need to balance the heating system.  Endless "how to's" on youtube.  Balance it on the lock shield valves (the ones at the opposite end to the TRV end).  Its a pretty boring, time consuming, job, but you should only have to do it once.

Albermarle

nofoollikeold said:

I suspect you need to balance the heating system.  Endless "how to's" on youtube.  Balance it on the lock shield valves (the ones at the opposite end to the TRV end).  Its a pretty boring, time consuming, job, but you should only have to do it once.

That was my first thought, but why would this one radiator suddenly start being a problem, when it was all OK before?

housebuyer143

Albermarle said:

nofoollikeold said:

I suspect you need to balance the heating system.  Endless "how to's" on youtube.  Balance it on the lock shield valves (the ones at the opposite end to the TRV end).  Its a pretty boring, time consuming, job, but you should only have to do it once.

That was my first thought, but why would this one radiator suddenly start being a problem, when it was all OK before?

Yes, this is what I don't understand. It's been working fine for a month or more as that's when the heating has been back on again - why would it suddenly stop being okay? 

It's gas central heating, system boiler. I switched over the TRV with one that I know works and the one from this cold rad works fine on the other, so it must be okay and it works when the rads are off. 

It's not just the rad that is cold either, it's all the pipes to it. 

Albermarle

There might be a partial blockage somewhere in the pipework ? When you switch off the other radiators it maybe causes enough pressure/ flow to get past the blockage.
Try switching off the other rads again. Then open up the TRV and lockshield valve fully, and put the central heating pump onto maximum speed ( there are usually some controls on the pump itself).
It might clear it, if it is a blockage. Can not do any harm anyway. 

housebuyer143

Albermarle said:

There might be a partial blockage somewhere in the pipework ? When you switch off the other radiators it maybe causes enough pressure/ flow to get past the blockage.
Try switching off the other rads again. Then open up the TRV and lockshield valve fully, and put the central heating pump onto maximum speed ( there are usually some controls on the pump itself).
It might clear it, if it is a blockage. Can not do any harm anyway. 

Thank you. I'll give it a try 🤞🤞

Belenus

housebuyer143 said:

Albermarle said:

nofoollikeold said:

I suspect you need to balance the heating system.  Endless "how to's" on youtube.  Balance it on the lock shield valves (the ones at the opposite end to the TRV end).  Its a pretty boring, time consuming, job, but you should only have to do it once.

That was my first thought, but why would this one radiator suddenly start being a problem, when it was all OK before?

Yes, this is what I don't understand. It's been working fine for a month or more as that's when the heating has been back on again - why would it suddenly stop being okay? 

It's gas central heating, system boiler. I switched over the TRV with one that I know works and the one from this cold rad works fine on the other, so it must be okay and it works when the rads are off. 

It's not just the rad that is cold either, it's all the pipes to it. 

The TRV actuator may be fine but have you checked that the pin in the valve is ok?

Remove the TRV and, using a coin or the back of a spoon or similar to protect your thumb, press down on the pin. It should go down and spring back up again when you remove the pressure.

If not, gently use pliers or grippers (use paper or cloth to protect the pin from scratches or marks) to move it up and down and see if that gets it working again. It shouldn't leak but have an old towel or something under it to protect the floor or carpet.

housebuyer143

Belenus said:

housebuyer143 said:

Albermarle said:

nofoollikeold said:

I suspect you need to balance the heating system.  Endless "how to's" on youtube.  Balance it on the lock shield valves (the ones at the opposite end to the TRV end).  Its a pretty boring, time consuming, job, but you should only have to do it once.

That was my first thought, but why would this one radiator suddenly start being a problem, when it was all OK before?

Yes, this is what I don't understand. It's been working fine for a month or more as that's when the heating has been back on again - why would it suddenly stop being okay? 

It's gas central heating, system boiler. I switched over the TRV with one that I know works and the one from this cold rad works fine on the other, so it must be okay and it works when the rads are off. 

It's not just the rad that is cold either, it's all the pipes to it. 

The TRV actuator may be fine but have you checked that the pin in the valve is ok?

Remove the TRV and, using a coin or the back of a spoon or similar to protect your thumb, press down on the pin. It should go down and spring back up again when you remove the pressure.

If not, gently use pliers or grippers (use paper or cloth to protect the pin from scratches or marks) to move it up and down and see if that gets it working again. It shouldn't leak but have an old towel or something under it to protect the floor or carpet.

Thank you so much for this detailed reply, I'll try that shortly and see if that gets it going.

Albermarle

housebuyer143 said:

Belenus said:

housebuyer143 said:

Albermarle said:

nofoollikeold said:

I suspect you need to balance the heating system.  Endless "how to's" on youtube.  Balance it on the lock shield valves (the ones at the opposite end to the TRV end).  Its a pretty boring, time consuming, job, but you should only have to do it once.

That was my first thought, but why would this one radiator suddenly start being a problem, when it was all OK before?

Yes, this is what I don't understand. It's been working fine for a month or more as that's when the heating has been back on again - why would it suddenly stop being okay? 

It's gas central heating, system boiler. I switched over the TRV with one that I know works and the one from this cold rad works fine on the other, so it must be okay and it works when the rads are off. 

It's not just the rad that is cold either, it's all the pipes to it. 

The TRV actuator may be fine but have you checked that the pin in the valve is ok?

Remove the TRV and, using a coin or the back of a spoon or similar to protect your thumb, press down on the pin. It should go down and spring back up again when you remove the pressure.

If not, gently use pliers or grippers (use paper or cloth to protect the pin from scratches or marks) to move it up and down and see if that gets it working again. It shouldn't leak but have an old towel or something under it to protect the floor or carpet.

Thank you so much for this detailed reply, I'll try that shortly and see if that gets it going.

For  sure this is worth trying as it is a common problem, but if the pin was stuck down ( as often happens) then the radiator would stay cold, even when you switched the other radiators off.