Two Bedroom Rads won't work - Scratcher

[Scratcher]

Winter 2015-6 : Two upstairs Bedroom radiators are not working.

Radiator 1 - had been switched off for couple of years because it hissed. Slight but constant noise.
Fault became apparent because Radiator 2 became half hot recently.
All summer the system had no use. Wasn't needed until colder months. No air was there to bleed.

The downpipe to Rad-1 is constantly cold, while the downpipe to Rad-2 is hot when system is active.

didn't work: Shut off ALL other radiators in the house and ran system for about 40mins. Still no change in temp to the rads or the downpipes.

didn't work: Instead of taking off and flushing the rads (we had no hose) Two NEW rads of same were bought and fitted.

didn't work: The system was flushed with a hose - only a bit of muck was dispersed.

Why if I have two new connected rads and filled with water by the system - why is none of it hot?

The boiler is a 5 year old Worcester combi. Can anybody solve this scratcher?

Cheers!

 

[Chalked]

Register on the forum and you will get an answer.
Thanks:teeth_smile:

 

[Scratcher]

Greetings all, I'm at my wits end with this one. I'd totally appreciate some guidance here.
Thanks,
S

 

[KingDoey]

Are the valves fitted to the offending radiators Bi-directional?

 

[Chalked]

Does it have a thermostatic valve? And if so, what make are they.

 

[Scratcher]

Thanks for the quick reply. I believe so and have uploaded a pic below :-

 

[Scratcher]

Yes I believe so. They are Conic variety. I've attached an image..

 

[Chalked]

Not sure on makes of those. But the pins could be stuck

 

[Riley]

I'd be looking at pins. Particularly if they've been off for a long time.