Radiators No Longer Heating

Sierra Oscar

Hi all,

I have an annoying problem with two of my radiators in my apartment which are no longer heating. First off, there are eight radiators in my apartment in total which are being heated by a gas boiler. For as long as I remember, the main radiator in the hall has not been heating. However as of late the radiator in the bathroom, which I believe to be the next in line to the malfunctioning hall radiator, has now stopped heating within the last week. I have tried dismounting the TRV's and have made sure that the metal 'pin' is not stuck or the like. The pin moves in and out of the radiator with ease in both of the radiators. I have also tried opening and closing the Valve on the left hand side of the radiator slightly but that has not helped either. Is there a chance that the balancing in the entire system is off? The radiator in the hall was not a concern to me, but the bathroom one not working is troublesome. I am also concerned that the problem could spread.

Also I can feel hot water at the outside of the left hand valve in the bathroom radiator, as if hot water it is wanting to get into the radiator. However this is not the case with the hall radiator. I have also tried bleeding the radiators and water comes out of both of them immediately.

Anyone have any ideas?

Also for reference I posted a thread here last year in relation to a faulty actuator. The plumber took the easy step and just removed the actuator entirely, which I was annoyed with - however as the landlord was paying the bills he said that the fix was satisfactory in nature. Could it be related?

shane0007

Sounds like sludge. When you bleed the rads, is it dirty or clear?
Try turning off the all radiators except the one that is not heating. Turn off the balancing valve on the cylinder coil also, but remember how many turns to the off position so you can reset it.

Sierra Oscar

shane0007 wrote: »

Sounds like sludge. When you bleed the rads, is it dirty or clear?
Try turning off the all radiators except the one that is not heating. Turn off the balancing valve on the cylinder coil also, but remember how many turns to the off position so you can reset it.

The radiators are only in place for three years or so, would sludge build up so quickly? I just tried turning all the other radiators off bar the two troublesome ones. The bathroom radiator is now heating and the hall one is heating somewhat, but barely.

GreeBo

Open the LockShields more than slightly, but an imbalance wouldnt suddenly appear.

Sludge (unless it has blocked the valve) would normally give you a cold pyramid in the middle of the rad.
Excess air (requiring a bleed) would give you cold tops to the rad.
So to me, it sounds like neither of them (in any case 3 years is far too soon for sludge)

However, there may be a blockage and really the only way you are going to know that is by taking the rads off the wall.
Close both valves, get some buckets under them and detach the valves from the rad, first one side (drain) then the other. Life it off (being careful of any remaining water) and try running a hose through the rad if you have access to one, even run water through it in the shower/bath to see if the rad itself is blocked (though if its able to bleed it wouldnt seem to be blocked)
Next the fun part.
With the heating OFF and the filling loop closed (assuming its a closed system in your apartment)
try opening the TRV slightly and see what sort of pressure you are getting out, the water should initially come out with a good bit of pressure and then die back down as the water levels drop. If you are only getting a trickle then your pipe/valve is blocked.

Repeat for the LSV.

jimjimt

Two valves on your rads.

One for turning on and off.

The other for balancing. This side may now be clogged from being tuned down too much.

Pull the cover of the balancing side and open a little more. You will need a spanner or pliers. It turns the same directions as a tap.
If open all the way already the problem is else where. But something to try.

Sierra Oscar

Also just to add, my flatmate tells me that his radiator is not heating all that much towards the top of the radiator - and that is the next one to the bathroom. So I am thinking it could be a balancing issue? Some of the radiators towards the start of the circuit are extremely hot to touch but the one in my flatmates room is merely mild.

jimjimt

not heating on top would seem like air in your rads as well.

Get a radiator bleed key at the hardware and bleed your rads. you also need to know how to let water into your system while bleeding and where to let the water in.

Sierra Oscar

jimjimt wrote: »

not heating on top would seem like air in your rads as well.

Get a radiator bleed key at the hardware and bleed your rads. you also need to know how to let water into your system while bleeding and where to let the water in.

Thanks, I bled the radiator in my flatmates room and there was an awful lot of air in it. I decided to bleed all of the radiators again as a result and there was also one other whereby a lot of air came out.

I notice that the pressure in the system has dropped dramatically, so you are right in that I need to let more water in. The only issue is that I am not sure how to let water back in, is the Valve usually at the boiler itself? I have attacked a photo of the Valves at my boiler.

EDIT: Think I found it, attached as second image. The pipe has "filler" labelled on it. Just want to be sure though before I go to let water in.

shane0007

The valve on the silver flexible hose on the right is the filling loop. Bring to 1.2 bar when system is cold.

Sierra Oscar

shane0007 wrote: »

The valve on the silver flexible hose on the right is the filling loop. Bring to 1.2 bar when system is cold.

Just tried turning it, doesn't seem to want to budge - would it be normal that I would have to apply a lot of pressure to open it?

shane0007

Looks odd. You have 2 fillers! One flexible on below boiler. This one has a black butterfly plastic turn valve, but is shown open in the picture. There is normally a second turn valve at the other end.
The other picture shows an automatic fill valve. Turn the black know anti-clockwise which is left upside down.

Sierra Oscar

shane0007 wrote: »

Looks odd. You have 2 fillers! One flexible on below boiler. This one has a black butterfly plastic turn valve, but is shown open in the picture. There is normally a second turn valve at the other end.
The other picture shows an automatic fill valve. Turn the black know anti-clockwise which is left upside down.

Ill provide a better picture of the filler system.

The pipe shown in the first image is leading into the boiler room and can be seen in the second image which leads into the flexible. There are two Valves on either end of the flexible, the first Valve I can open and close but the second Valve nearest the boiler is totally stiff (but seems to be open in anycase).

When I adjusted the black knob to the left the black needle drops, but there is no effect on the boiler pressure monitor (third image). The boiler pressure monitor was above 1 before I released the air from the radiators.

There is also another Valve on an offshoot pipe from the filler pipe before the automatic fill Valve, but I doubt that is related? (IMG4)

shane0007

Ok. By the looks of it, the auto fill valve is feeding the filling loop. If the black knob under the auto valve is fully open anti-clockwise, try turning the threaded part on top with a flat head screw driver. This is for setting the max pressure allowed to pass through the valve. If this does not work, the fill valve is knackered but it is not required anyhow.
You would then need to turn off the mains supply, release pressure by turning on kitchen sink cold tap. Remove the auto valve and link the two pipes with 2 x 1/2" 310s and a small piece of 1/2" copper tube.

Sierra Oscar

OK, when I turned the threaded top of the auto fill Valve there was a negligible rise in pressure indicated by the black pin. If the first Valve in the flexible is closed the black pin rises to 1.5 - when I reopen the Valve on the flexible it falls back down. The pressure indicator on the boiler itself is not changing at all though.

shane0007

There is also a built in non-return valve on the filling loop. This could be stuck. What you are describing really sounds odd though.
Try turning off the first black valve or both on the loop. Turn off the black knob on the auto valve. Open the joint coming out of the auto valve to the loop. Holding a basin, slowly open the black knob to see if there is water pressure. If so, then there is likely to be an issue with the non-return valve on the loop. If no pressure then it is the auto valve. Auto valves are normally the culprits though.

Sierra Oscar

The heating was on for a while earlier on, and all of the radiators are now heating normally except the one in the hall (which has not been heating for as long as I have been in the apartment) so that is some positive news at least. However I am still a little concerned with the pressure in the system as I know the boiler will stop functioning if it drops too low.

Anyway after the heating being on the pressure rose to around 1.1 bar and now that it has been off for half an hour it is falling back down to 07. bar. What should the optimal pressure be when the system is entirely cool, 1.2? Also I now notice that the pressure being indicated by the boiler is matching the pressure indicated by the auto fill valve (but that could just be a coincidence for now).

I reckon I might have to end up getting a plumber in to look at the radiator in the hall as I cant seem to sort it myself. I might try and insist that the landlord get someone to service the boiler while I am at it, the boiler hasn't been serviced in well over a year.

shane0007 wrote: »

Try turning off the first black valve or both on the loop.

I can turn off the first valve furtherest away from the boiler, but the one closet to the boiler just does not want to shift at all - it feels that it could nearly break if I put any more pressure on it to turn it.

shane0007

System pressure when cold 1.2 bar.
Boiler service would be a good idea as the issue may be the expansion vessel pressure and/or 3 bar safety valve letting by. Check outside pipe coming from boiler for drips.
Re: the valve it turning off, this could be the issue. It could be off but the handle is showing on. There is a small Phillips head screw holding the plastic lever on. Unscrew this & turn with a pliers. See is this the issue.

Sierra Oscar

Thanks Shane, it dropped to around .5 when the system had time to cool so I will definitely try and get someone to have a look at it if I cant manage to sort it. Im going to try your suggestion with the Valve in the morning!