little to no heat in rads,,, getting desperate

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Dear all
No heating for a week now and the wife and kids are losing sense of humour. Me too!

I have no flow or v slow flowing central heating. Upstairs rads heat up v slowly and no heat downstairs. Boiler out pipe gets very hot though all the way up to and beyond the pump.

I think the pump is OK as it is flowing through the little bathroom rad on its own loop. Also heating the hot water OK. I've switched off the bath rad as it was just pumping round this tiny loop and no heat going to any other rads. Switching off pushed more heat to upstairs rads but still mostly cold after an hour. I've got the taps wide open.

Worcester boiler engineer came out and pronounced it is fine. Although it is overheating if I just run the central heating side of things.

System drains down OK too. So I don't think its a dodgy valve.
I even back flushed by attaching the garden hose to the drain tap. Water coming out fine into the header tank.

Return pipe to boiler seems to stay cool. Something is getting through but very little.

Does this mean the pipes are blocked on the return loop to the boiler?
I can't think of another explanation.

Starting to get desperate now. Is it time for a power flush?

I don't know how else I would get to that part of the loop.

Tips most welcome.

Ta

S
 
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Is the pump running? is the pipe work hot either side of the pump?

Have you tried to move the lever on the 2/3 port valve?

Andy
 
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You have been asked several times to latch the motor valve and see what happens.

But for some reason you seem not to want to do that!

Until you do then we cannot help you any further!

Tony
 
Until you do then we cannot help you any further!

Tony
:eek: :eek:

I thought that as the unit had been replaced and the symtoms remain unchanged that this made it very unlikely to be the diverter. But I will try it if you think I should.

Regarding the balancing of rads and that some might be stealing heat. Im not an expert on this but none of them are getting hot enough to suggest this might be happening.

It feels like the water isnt getting pushed round so heat is only creeping round the upstairs rads and not getting downstairs at all.

I dont think there is a blockage in the rads either as when I drain down or back flush water comes through easily. That suggests that there is a blockage between the bottom rad and the return to the boiler... doesnt it?
 
And have you done the finger test on the pump? See FAQ.

Merely replacing one part will not solve a problem which is caused by something else.

It would be like fitting a new tyre on a car which had run out of petrol!

Tony
 
Faulty 2/3 port valve, latch the lever on the valve to the open position and see if the rads heat up.

See the lever from 2.12 sec

http://www.youtube.com/watch?v=T7UTDtrmcvM

Andy

Mine is a Drayton . I tried moving the side switch but didn't want to snap it off, as had happened on the old unit. But it is turning to H as soon as I change the boiler settings .

Rads still not getting heat.

I'm just about to undo the drain valve on the lowest rad to see if hot water flows from boiler. Back in a sec
 
Right, I just opened the drain and hot water came out in a nice hefty stream.
Does this mean there is no blockage upstream and that there is a blockage downstream to the return to boiler pipe? This would make sense as when I touch the return pipe just before the boiler it is cold, yet the pipe just after the pump is v hot.

But what the hell do I do now? Rip up boards and start replacing the return pipe????
:eek:
 
And have you done the finger test on the pump? See FAQ.

Merely replacing one part will not solve a problem which is caused by something else.

It would be like fitting a new tyre on a car which had run out of petrol!

Tony

Hi Tony. Yes, I've had the central screw off and its running OK. Also took the head off to see impeller had gunged up but that also looked good.

My local plumber thought it might be an old non return valve that had gone but I've dug around under the boards and I can't see anything that looks like that.
 
The lever can only go to the other side of it's casing. You can't pull it to much.

Did you un-latch it first?

Andy
 

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