Radiator Has Us Beaten What Way Should It Flow ?

[muzzmackay]

I'll provide as much info as I can:

I have a pressurised central heating system running 8 radiators. All have TRV's fitted although now we have a room thermostat they are all run fully open. The radiator furthest from the boiler and in the coldest part of the house never warmed up last winter.

What I have done so far with no success.
I bled it. Removed it and flushed it out. WD'd and tapped TRV pin with hammer. Removed it again, this time when I replaced it I opened the TRV side first an no water flowed into it. Closed this side and opened the lockshield side which did allow water in.

I then unscrewed the nut between the TRV and the incoming 15mm pipe expecting water to hiss out but there was no pressurised water.

All the above leads me to ask. What way should the water be flowing into the radiator ? If from Lockshield side then it may just be that my TRV is stuck solid closed. If there is supposed to be a pressurised flow into the TRV side then I'm stumped.

 

[bengasman]

Take trv off, and blow through it.
If trv is stuck shut, replace it and clean system.
Once the rad gets warm, system needs balancing.
If the trv was faulty, pretty sure system needs cleaning
You may have a roomstat, that doesn't mean you should fully open all trv's, that defeats the purpose of having trv's, see FAQ

 

[muzzmackay]

Problem solved. The TRV was sound, removed it without any loss of water.
Put the heat on and manage to access the manifold under the floor and determine which pipes were not heating up.
Heating / boiler off all rads closed. Loosened then removed microbore for naughty pipe at manifold and pushed in a long piece of brake cable from other end. It didn't come all the way out !
We then discovered a large whitish coloured blob had blocked the end of the microbore, identified as compound or putty. Had to drill through it to get it out !

Refilled system, heat on, hot radiator

 

[bengasman]

This might be the time to install a filter

 

[Agile]

I'll provide as much info as I can:

I then unscrewed the nut between the TRV and the incoming 15mm pipe expecting water to hiss out but there was no pressurised water.

We quite naturally interpreted what you said as meaning that its a standard system fitted with 15mm and 22 mm.

It now turns out that its a microbore system!

The TRVs should also be set to the appropriate setting except in the room where the room stat is where it should be fully open.

Tony