Radiator issues

[markyboy07]

Tried the heating a couple of weeks back and the front room rad was not heating up, it was warm in the pipework but no where else. This has happened most years and is usually sorted with a couple of Whacks to the thermostatic valve. This year it was having none of it, so last week I bought 4 sets of thermostatic valves and whatever the other valve is called?? Drained the system changed the valves filled her back up and bled them all, first fire up resulted in one upstairs radiator getting warm and all the rest cold,as it was late I left it till the next day to figure out. Over night I heard lots of rumblings and movement and the next day with another bleed all worked apart from the one front room radiator.

     At the weekend, I started again drained everything and re soldered some new pipe work as a lot of the old olives were knackered and were causing some weeping on the valves. When I fired it up the same thing happened again, one worked initially and then after some more bleeding all worked apart from the one bleeding radiator in the front room aaarrrrgghhh!!!

I'm guessing the problem is an airlock, I have concrete floors downstairs and it appears that every downstairs radiator is fed individually (i.e no downstairs curcuit) from up stairs, each downstairs radiator is fitted with its own drain off valve.

 So what I want to know is how do I fix it??????🤔

[TIGHTCHOKE]

Can you isolate the radiator in the front room? Then bleed the air out and slowly open the flow side.

[B725]

For Trv,s to keep sticking it's because of the black sludge in the system. Hire a cleaning pump set and clean out the system and add Sentinal inhibitor to it. When you vent the radiators start at the one furthest away, do all the downstairs before going upstairs. ( I can only assume it's tank fed) 

After venting all the rads if you still have the same problem put the heating on and start to turn off the rads upstairs then downstairs apart from the one that is not working, you are now using the heating pump to help move the air that will be trapped in the pipe work, there must be a high point on the pipe work to that rad. 

[B725]

You could do it another way, on the cold rad turn off both radiator valves and remove the radiator. With a large bowl placed next to the valve slowly open it and let it run but not too fast until the water runs hot and or stops spitting air from it, repeat on the other side, refit the rad and vent as normal. 

[markyboy07]

4 hours ago, B725 said:

For Trv,s to keep sticking it's because of the black sludge in the system. Hire a cleaning pump set and clean out the system and add Sentinal inhibitor to it. When you vent the radiators start at the one furthest away, do all the downstairs before going upstairs. ( I can only assume it's tank fed) 

After venting all the rads if you still have the same problem put the heating on and start to turn off the rads upstairs then downstairs apart from the one that is not working, you are now using the heating pump to help move the air that will be trapped in the pipe work, there must be a high point on the pipe work to that rad. 

Yes it is tank fed, and that is the way I vented it, started downstairs and then upstairs venting the tall rad in the bathroom last. But I will try turning the rest off and running the heating,thanks for the advice will let you know how I get on.

[markyboy07]

4 hours ago, B725 said:

For Trv,s to keep sticking it's because of the black sludge in the system. Hire a cleaning pump set and clean out the system and add Sentinal inhibitor to it. When you vent the radiators start at the one furthest away, do all the downstairs before going upstairs. ( I can only assume it's tank fed) 

After venting all the rads if you still have the same problem put the heating on and start to turn off the rads upstairs then downstairs apart from the one that is not working, you are now using the heating pump to help move the air that will be trapped in the pipe work, there must be a high point on the pipe work to that rad. 

Yes it is tank fed, and that is the way I vented it, started downstairs and then upstairs venting the tall rad in the bathroom last. But I will try turning the rest off and running the heating,thanks for the advice will let you know how I get on.

Well that was easy, did as you said and I have a warmish radiator, still a bit of bleeding to do and I think I will get the system flushed out to be in the safe side.

Thanks to both of you for your advice.

Edited October 23, 2022 by markyboy07

[Westley]

On 23/10/2022 at 11:57, B725 said:

You could do it another way, on the cold rad turn off both radiator valves and remove the radiator. With a large bowl placed next to the valve slowly open it and let it run but not too fast until the water runs hot and or stops spitting air from it, repeat on the other side, refit the rad and vent as normal. 

This   👍

Years ago we would take the boiler stat phial out of its housing and 'boil' the system. You got one hell of a lot of rumbling from the pipework, but it always shifted the air  !     😉