central heating issue

[GrahamJ100]

Good morning the issue I have is that we have a radiator in the attic bedroom and the rad is not warming up bought new valve in case old one was stuck no difference I have bled the radiator no joy ive even taken it off the wall and lugged it into the garden and flushed it through with the hose pipe when refilling the system it fills up all the other radiators are boiling
so last night I turned all the working rads off valve and balancing valve
opened up both valve fully on non working rad still no joy this morning I have opened up the valves by half a turn on all the other rads and they are now lovely and toasty but still no heat to the last rad has anyone encountered this issue I don't believe its the pump as surely all the other rads wouldn't work many thanks

 

[ShaunCorbs]

Has it ever worked?

 

[Harvest Fields]

Was it working then stopped or has it never worked?

 

[GrahamJ100]

yes was working fine up until a few days ago when it needed bleeding as it was luke warm refilled then bled then stone cold ,theres a gate valve in my bedroom that looks like it joins up the heat pipe and the return pipe I'm assuming this should be closed !! the pipe that leads to the thermostat valve is piping hot yet the return pipe is stone cold as I say ive bled re bled flushed and am not mega unsure of next step
any help would be gratefull

 

[GrahamJ100]

also when ive emptied the rad in question and refilled the rad I bleed it and it filled back up as there was a steady flow of water once air had gone

 

[Harvest Fields]

So one pipe into the rad is hot?

 

[gmartine]

the pipe that leads to the thermostat valve is piping hot yet the return pipe is stone cold as I say ive bled re bled flushed and am not mega unsure of next step
any help would be gratefull

TRV sensor could be faulty, remove the actual TRV head and make sure the valve is operational by pressing on it a few times, if it is then see if the rad warms up without the TRV head in place. If the valve is stuck fast there's your problem.

Ah sorry just read the op properly

 

[GrahamJ100]

yes its that hot u can only touch it for a few seconds ,the rads full of water yet its cold water so I was wondering about the return pipe ? if theres a air lock in that how would I clear that so the water flows round the rad

 

[GrahamJ100]

its def not the valve ive replaced the valve and the valve ive replaced iv also taken off and put one that opens up with a spanner so def not the valve

 

[Harvest Fields]

Did you change both valves? To be honest it Sounds like an air lock to me.

 

[GrahamJ100]

no ill change left hand balancing valve and see what that does if not how would I go about unblocking the airlock ,,shall I open up the bleed valve and just let the water come out till it comes to the hot water ?

 

[Harvest Fields]

no ill change left hand balancing valve and see what that does if not how would I go about unblocking the airlock ,,shall I open up the bleed valve and just let the water come out till it comes to the hot water ?

Try turning the trv off and open the plug the opposite side of the vent/bleed point and run some water through that way

 

[GrahamJ100]

ok that's just a nut when filling that do I open up the bleed valve as well or just fill up from left hand side of radiator
many thanks for the info

 

[jtsplumbing]

If rad is empty turn off TRV disconnect locksheild valve from rad , open up valve and see if you get any water through, when it starts getting hot reconnect to rad and fill rad from that side, them open TRV

 

[GrahamJ100]

hi good morning so this is what I did this morning shut off valve on thermostat side then disconnected left hand balancing valve lots of cold water cam out of pipe from floor board then it became warm ? on the radiatior side emptied water till it became best I can describe is luke war wasn't constantly poring out ...so I reconnected balancer pipe refilled system bled then refilled then bled then we had warm heat going through great went back to check ten minutes later its now luke warm not roasting like other radiators bled again water came straight out ,now its too hot to touch where it goes in to rad ??? so why is the radiator not getting hot

 

[Harvest Fields]

How old is the radiator?

 

[GrahamJ100]

a good ten years maybe its time to get a new one they are not too much its only a smallish do you think there could be a blockage even though I took outside and flushed and all that came out was clear water ?

 

[Harvest Fields]

It’s a possibility. Or there is still a restriction in the return from the rad.

 

[GrahamJ100]

the valve is fully open only thing I can think of now would be the radiator and for the sake of thirty to fourty quid I think that would be the next step just out of interest rather than filling from boiler side would there be an advantage to removing nut from opposite side of bleed valve and re fillking the rad from there in case of an air lock that wont shift ?

 

[Harvest Fields]

You could try it.

 

[jtsplumbing]

Well you have tried everything, only other thing is pump is getting weak, how old is pump ?

 

[GrahamJ100]

8 years surely heat rises therefore if the pump was on its way out the rads downstairs wouldn't be getting warm ? I think for the sake of a few quid ill change out the radiator just to be sure theres heat there now but just luke warm and the return pipe is cold so I reckon its just not getting through the rad thanks for all your help appreciated

 

[ShaunCorbs]

Did / we're you getting the same flow out of both valves ?

 

[GrahamJ100]

the balancer side when drained hardly anything coming out until I opened bleed screw and more cam out at a steady flow but didn't come out boiling if u know what I mean at that point I thought that there wasn't enough water in system because I'm draining therefore that's when I sealed all up and refilled ...

 

[GrahamJ100]

the return pipe when disconnected shoots a small amount of cold water out the a short bit of hot water then stops ,,if that makes sense

 

[ShaunCorbs]

Was the trv / non balancing side boiling hot ??

 

[GrahamJ100]

yes the trv side was too hot to touch

 

[GrahamJ100]

and if you put your fingers under the rad u can feel the heat underneath a bit

 

[ShaunCorbs]

Was the other side full flowing ?

 

[GrahamJ100]

not sure what u mean the other side is opened up fully and is stone cold if I disconnect the other side (balancing side ) a load of water comes out of rad and eventually gets warm a little ,a small amount of water ejects from return pipe again cold then goes warm a little

 

[ShaunCorbs]

Yea that's fine so your getting good flow from both

I would say blockage in the rad or pump

 

[GrahamJ100]

the flow pipe and the return pipe from the offending rad comes down my bedroom cupboard the flow pipe is too hot to touch and the return pipe is cold there is what looks to be a gate vale where a pipe connects the flow with the return this is closed I'm assuming it should be closed ?

 

[Harvest Fields]

Have you tried opening it? To see?

 

[ShaunCorbs]

Any chance of a pic of said valve ?

 

[GrahamJ100]

yes have opened it but not sure what its there for ?