Radiators Cold upstairs Pump Problems or sludge?

[retroviper]

Hi.
3 out of 4 upstairs radiators are stone cold I will try to give as much information as I can.

Boiler is a Glowworm Micron on a S plan.

Both zone valves were replaced last weekend as they were leaking through the valve body but this was a existing problem.

All the radiators that are not working have TRVs I have removed the heads and the pin feels pretty free.

Have tried bleeding all radiators the upstairs one closest to the boiler is working but the other 3 are not.

Have tried turning off both valves to one of the radiators and removed the bleed valve completely and then turning the TRV on again but no water comes out of it.

One radiator is missing at he moment for decorating purposes.

Have tried closing the TRV valves on the ones that are working but still no joy.

I can hear the pump and hear the difference between the speed settings (set on 3 at the moment) but not sure if it is actually working or not and the tank in the loft is full.

Any ideas?

 

[aggis]

Hi, Are your downstairs rads working?

 

[retroviper]

Hi
Yes all of downstairs are working and the one upstairs closest to the boiler.
5 rads downstairs (one removed) 4 upstairs.

 

[aggis]

It's not your pump if d/stairs are hot.
You say the header tank is full, is the cold feed gate valve open, try bleeding rads.
otherwise it's got to be flow to or from the rads. Check both valves are open, remove trv head & tap the pin, does it feel springy, try & free if stuck by tapping down.
If no luck you might have to take the rad off the wall & check water flow by opening each valve separately & running into a bucket. no flow or reduced, that pipe's got a blockage.

 

[retroviper]

Still no luck I have taken a radiator off the wall upstairs washed it out etc and got a bucket and opened the valves.
only seems to be a trickle coming out of them even with the TRV off and pulling the pin.
Only seems to be the flow side as the return seems ok.
Whats the best way to free the pipe some chemicals or may they have to be replaced?

 

[dontknowitall]

Assuming you've taken the rad off and left with just the TRV and tried opening it to find a trickle, I suspect the TRV has failed and it's probably easiest and quickest to buy a new one.

 

[retroviper]

Cheers for the advice will try to take the valve off and put a standard one on.
How long should TRVs last for? They seem to have loads of problems with them.

 

[dontknowitall]

Nothing seems to last these days like it used to. I wouldn't like to say more than five years but could well go for 20 or so. Don't go too cheap - you can buy them for £5 upwards. I tend to spend around £10-£12.

 

[retroviper]

Thanks guys for all your help was the TRVs completely stuck down. Took them off and WD40 them must have used half a can!!!
They seem more hassle than their worth TRVs you all must get loads of work out of them.
Cheers again.

 

[RoryD]

Hopefully you haven't got a one pipe system because by turning one off to remove the rad for decorating, you will cut the others off. Other than that u got sludge