Radiator in front room not heating up.

[pcuser]

Back in November 2018 radiator in living room was just say warm, all other radiators were very hot, 12 in total, i changed the radiator as i thought this was the problem, still no better. I had the boiler serviced recently and the engineer suggested it was sludge in the system. I have since drained the fill and expansion tank in the loft, via hosepipe as it was filthy, cleaned out the f & e tank, filled it with clean water, drained off the water in the radiator system which was pretty clean and it had some x100 inhibitor in, added some x400, doing a great job with all other radiators but not the problem one.

The lockshield gets very hot, the valve on the other side stays cold. Yesterday I drained the radiator, kept the x400 cleaner, flushed out the radiator in the garden with a hose pipe, water was very clean, very little crap came out. Water flows fine from the filling valve but very slow from the lockshield valve.

Any help would be appreciated to get this one radiator working again.

The sytem is an open system with f and e tank in the loft, pump, hot water storage tank and 3 way valve in cupboard upstairs, cold water tank in the loft, boiler downstairs in utility. Boiler is serviced annually by certified engineer.

 

[pcuser]

I have also tried turning off all other radiators to try and force heat through, the boiler closes off and radiator still doesn't get hot. The other radiators get hot pretty quickly just not the one in the front room.

 

[Aire]

Either A faulty lockshield or the pipe feeding it is blocked.

 

[New Gas Engineer]

Id change the lockshield to begin with.

You could test your existing lockshield. All you have to do is lock/close the lockshield, drain and remove the rad and open the lockshield with a container beneath it to see if water comes out or not. It should be coming out with some force. If its just trickling then it needs to be replaced.

 

[pcuser]

Thank you both for the replies. At the moment i have x400 in the system giving it a good old clean, when i come to flush and drain down the system next weekend i will replace the lockshield valve and the filling valve with new ones. Hope this will solve the problem as pipes are buried in the wall's. Thanks once again.

 

[pcuser]

Just tested both valves on either side of this radiator, both flowing fine, attached my hose pipe to them, one side at a time, (i created a vacuum in the radiator so did not need to drain), warm water flowed from the fill valve and coldish water flowed pretty fast through the lockshield, i was able to control both valves no problem.

 

[Riley]

It should come out at a fair gush

 

[pcuser]

It should come out at a fair gush

The lockshield side came out at a slower rate than the fill valve did but still flowed just not gushing out, i did have all other rads in the house turned off.

 

[Riley]

Turning off the other rads shouldn’t make any difference. All it means is they won’t drain. The water from the F&E will still flow all the way down to the valves you’re working on. Not really sure what you mean by created a vacuum in the radiator

 

[pcuser]

It should come out at a fair gush

What i did notice with the lockshield was that the flow did not increase the more i opened the valve. Thanks for the help.

 

[pcuser]

Turning off the other rads shouldn’t make any difference. All it means is they won’t drain. The water from the F&E will still flow all the way down to the valves you’re working on. Not really sure what you mean by created a vacuum in the radiator

There was just no flow from the radiator as all other valves/air vents were closed, of course i had a bowl below just in case.

 

[Riley]

But there would still be water feeding from f&e sounds like a blockage

 

[pcuser]

But there would still be water feeding from f&e sounds like a blockage

What would be the easiest way to clear it? without having to replace pipes.

 

[Riley]

Can you access both ends? What size pipe?

 

[pcuser]

Can you access both ends? What size pipe?

Unfortunately not. Piping is 10mm minibore and buried in the walls, possibly goes back to the upstairs cupboard where the hot water cylinder, the pump and diverter valve are located.

 

[Riley]

Could I suggest a pro to try and trace it

 

[pcuser]

I am going to drain the system next weekend and flush out the x400 cleaner that i put in the system last weekend, i am also going to change the lockshield valve on the offending radiator whilst system is drained, if that does not fix the situation i am calling in the experts. Thank you for all of the help and support from all. Thanks Riley for the help.

 

[pcuser]

Thought i would post an update on my radiator not heating up, I drained the system today, attached a washing machine hose to the radiator valve and forced some air down the radiator pipe using a foot pump, repeated the process 3 times then out the blockage came, with some force, pleased i had the plastic down and towels to the ready, replaced the radiator valves and radiator, i bought these just in case to be prepaired. Radiator now red hot.
I also had the pump replaced to a more economical and energy efficient one.

I can certainly recommend x400 it did exactly what it said on the tin, (first central heating system clean in 16 years), system heats up quicker and is a lot quieter. One sytem flush done, 2 more to go before the x100 goes in. Thanks to all for the help.