Rad not heating - Connection is hot

sasol

Hi,

I am living in my newly built house for the past 10 months. I have one rad that will not heat.

I have oil central heating with a Grant Condensing boiler.

Downstairs I have underfloor heating in two rooms and 6 rads in the other rooms, all of which are working fine.

Upstairs I have 5 rads and two towel rads. Four of these rads and the two towel rads are working fine. It is one of these upstairs rads that I am having problems with.

When I feel the connection to the problem rad, right at the base of the rad, it is hot. But the rad itself is always cold at the bottom and sometimes it is barely lukewarm at the top.

I have bled this rad countless times at this stage and bleeding it usually doesn;t make any difference. I have turned off all the upstairs rads and left this problem rad on, and this does get the rad hot, but after a few days, I am back to square one - the rad will not heat eventhough the connection at the base of the rad is hot, which indicates to me that the heat is getting to the rad but the rad is just not heating.

I am attachin some photos which will explain better - any help or suggestions would be much appreciated.

Thanks,
S

JohnnieK

It's possible the return valve (the one you can't turn on or off) is turned down too much. Take the cover off and using an adjustable spanner open anti-clockwise a quater turn. See if this makes any difference. If not open another quater turn.
Come back with your findings.

sasol

JohnnieK wrote: »

It's possible the return valve (the one you can't turn on or off) is turned down too much. Take the cover off and using an adjustable spanner open anti-clockwise a quater turn. See if this makes any difference. If not open another quater turn.
Come back with your findings.

Thanks for the reply - I am hopeless when it comes to anything to do with plumbing, so just to confirm - the cover I should be taking off is the cover I have marked on attached photo ?? And the valve I need to turn is behind this ?

JohnnieK

sasol wrote: »

Thanks for the reply - I am hopeless when it comes to anything to do with plumbing, so just to confirm - the cover I should be taking off is the cover I have marked on attached photo ?? And the valve I need to turn is behind this ?

That's correct.

heinbloed

Get the so-called plumber in who has installed the CH system.
The hydraulic balancing wasn't done according to the symptoms described.

The method described by JohnnyK will make things worse (by imbalancing the rest of the system) - if the CH system was installed by a professional who did a propper job.

With a building project going on since 5 years ( http://www.boards.ie/vbulletin/showthread.php?p=57996768) there is propably lost a lot of previously existent knowledge, esp. if lay-out of the system and the anual maintenance wasn't 'recorded'/protocolled, i.e. done at all.
In such a case a heating engineer would be the right person to have a thorough check of the CH system. Ask for a maintenance of the CH system. And pay for the job.

Heinbloads right, I'm drunk, happy birthday to me....

JohnnieK

He's right of course. Turning the valve a quarter will throw the rest of the system into turmoil.
Careful Heimy I'll get nuzzer after you.

shane0007

Lol, Heinbloloc upto his old tricks again....

Check the head of the pump, it may not be large enough to get sufficient flow to all parts of the system.

Do check what JohnnieK suggests, you can always count the amount of turns you do so that it can be re-instated if all other parts of the system become suddenly cold because of yours actions!!!! hmmmm.....

Happy birthday Gary71

sasol

JohnnieK wrote: »

It's possible the return valve (the one you can't turn on or off) is turned down too much. Take the cover off and using an adjustable spanner open anti-clockwise a quater turn. See if this makes any difference. If not open another quater turn.
Come back with your findings.

Hi - I am coming back to this again. I took the cover off, as suggested, and there are three potential options to turn.

See attached.

Which one of these should be turned in the anti-clockwise direction ??

Thanks again.

davymc31

number 3 turn anti clockwise until it stops then see does rad get hot make sure heating has being on for a while if it gets hot straight away it means it was turned too much clockwise

spireland32

turn number 3, anticlockwise standing straight on in front of it. try 1/4 at a time to see if it heats up, waiting a few mins between each 1/4 turn. check balancing valve on the hot water cylinder aswell

JohnnieK

As above. Turn quarter turns at a time waiting after each turn.