A couple of radiators in the house are hot at the bottom and cold at the top……..easy I thought, I’ll just bleed them.

So I unscrewed the bleed valve and air hissed out but when it stopped it didn’t result in water dripping out.

I assume this means there’s a blockage? Any ideas/suggestions?

How old are the rads??

Not too sure, only moved in 6 months ago (i.e. when we didn’t really need the heating on) and can’t find anything amongst the instructions etc. the previous owners left regarding heating.

you might need to add more water pressure in the system. If its a combi there should be a fill loop tap – usually a flexy steel braid hose near the boiler. Look on the boiler for a pressure guage – check its in its “green” zone, if its below the correct pressure level, then open the filler loop to re pressurise the circuit until at correct pressure then shut off fill loop tap. re bleed rads until water comes out. Re fill circuit back up to target pressure if necessary.

Stoner what will achieve those results? Need to push at least 2 bar into the system?

your boiler will tell you what pressure the heating circuit should be at. What can happen when your bleeding is if there’s lots of air in the circuit, when you bleed it out you reduce the pressure to being 0 relative to atmospheric so it cant “bleed” any more. As you repressurise then theres sufficient differential to finish off the bleeding.

Stoner – I’ll have a check shortly and check.

I assume being an oil fired boiler has nothing to do with it? Always had gas before moving here.

Thinking about it that relative pressure makes sense.

Is it a Vented system or not then?

Imagine if your radiators were filled with Human Blood and then just suddenly all burst with blood pouring out of them all over everything…

It’d be a bit worrying wouldn’t it?

Only if it was my blood i suppose.

If it’s not a sealed system and not refilling itself, then the water feed to the f&e tank in the loft could be off, or frozen even. It should only be about 4 inches deep in water though.

If you don’t know what that is, it’s a small plastic tank in the loft somewhere, probably around the size of a very large bread bin.

Cheers Stoner – Turned out to be a sealed system – ‘re-pressurised’ the syetem with the filler tap on the boiler and managed to bleed radiators and get them to work.

All now good except for one radiator which I’ve bled fine but doesn’t get warm at all, not even the feed and return pipes to the radiator get warm.

Not sure what’s wrong with it – if I can bleed it then it can’t be blocked? Can it? Any ideas?

Desparately trying not to fork out for a plumber this close to Chrimbo! 😳

are both valves on the rad open?

if only one is open then it will bleed but not warm up.

If it’s not a sealed system and not refilling itself, then the water feed to the f&e tank in the loft could be off, or frozen even. It should only be about 4 inches deep in water though

A few years ago our feed supply was blocked by, well, shite, in plain english – rusty corroded crap that the repairmen reckoned had probably been there since new. Whole system needed flushing out (£500) and the feed pipe replacing. Happened in the spring thankfully, so not too Baltic at MFL towers when it happened.

what wwaswas says, are both the TRV and lockshield open?

If yes, and the rad that wont get hot is the last one in the circuit you may need to balance the system – adjust down the lockshields on the other rads a bit so that there’s some oomph* to get the hot water all the way to the end.

* very technical weekend plumber’s term.

[video]http://www.youtube.com/watch?v=FMaA7Dwc314[/video]