Radiators: SORTED but now needs a 'power flush' ??

AdamBrunt · 17 Dec 2007

Hi all,

Sure the above question has been asked before.

Read some replies about needing to balance the system but not sure what that entails.

Basically all the radiators upstairs are working but, without changing anything in the system, a couple of days ago the downstairs radiators have stopped working.

So far I can only see that the "in" pipe into one of the downstairs radiators is warm to the touch (as is the LSV(?) on the radiator), yet the radiator itself and "out" pipe (and all the other feeds and radiators downstairs) are stone cold. I then bled the radiator (didn't hear any air coming out just water) and am waiting to see if the radiator warms up.

If it makes any difference, there is plenty of hot water coming through the taps downstairs.

Anyone got any other ideas ?

Regards,

Adam Brunt

gas4you · 17 Dec 2007

Check your pump. It is probably stuck at best, knackered at worst.

AdamBrunt · 17 Dec 2007

gas4you said:
Check your pump. It is probably stuck at best, knackered at worst.

Ok - call me Mr Thickie but how do I do that ?

Also, wouldn't a pump problem mean the in pipe, which is currently warm, should be stone cold as well ?

gas4you · 17 Dec 2007

Undo the large screw in the center, put flat balded screwdriver in, locate in slot and see if it will turn.

A spinning pump can spin but not circulate.

tryitandsee · 17 Dec 2007

Adam, give us all a bit to go on. Is it a combi or coventional system.

It may all be working by convection at the moment, hence pump not working suggestion earlier.

AdamBrunt · 17 Dec 2007

tryitandsee said:
Adam, give us all a bit to go on. Is it a combi or coventional system.

It may all be working by convection at the moment, hence pump not working suggestion earlier.

conventional system.

have now found another radiator downstairs with warm "in" pip but cold everywhere else. bled this "new" radiator and, unlike the first one where it was just a trickle, the water spirted out all over the place. A pressure problem perhaps ??

Problem is - haven't had any problem since moving in (over 6 years ago) so am unsure which pipes go where and which radiators are end of the "chain" etc, etc.

tryitandsee · 17 Dec 2007

gas4you said:
Undo the large screw in the center, put flat balded screwdriver in, locate in slot and see if it will turn.

Have you done what gas4you suggests. but use a non 'balded' screwdriver, the ones with hair are better

AdamBrunt · 17 Dec 2007

Just tried to check the pump.

I am guessing it shouldn't be boiling hot to touch ? Cos it is.

tryitandsee · 17 Dec 2007

The pump probably will be hot, it may be working, let it cool off and try and eliminate it as either working (spinning) or not.

Are the downstairs rads on thermostatic radiator valves, they cant be all stuck, can they!

AdamBrunt · 17 Dec 2007

tryitandsee said:
The pump probably will be hot, it may be working, let it cool off and try and eliminate it as either working (spinning) or not.

How ? By turning the heating off ?

tryitandsee said:
Are the downstairs rads on thermostatic radiator valves, they cant be all stuck, can they!

There are 5 radiators downstairs all with thermos. All 5 radiators are stone cold.

The pipe going into the thermo on 2 of the rads is warm to to the touch at the thermo. On the one of these pipes, the pipe is boiling hot at ceiling level - can't access the pipe, to the other rad, at ceiling level.

All the pipework for the other 3 downstairs radiators is at floor level.

tryitandsee · 17 Dec 2007

Sounds to me you have an airlock, try this: shut all rads upstairs off, turn the pump up to fast speed (if you have variable pump), turn the cylinder stat down to low (this will shut down the motorised valve and push water around the heating circuit).

Something to do, better than watching poor old Billy mitchell.

AdamBrunt · 17 Dec 2007

tryitandsee said:
Sounds to me you have an airlock, try this: shut all rads upstairs off, turn the pump up to fast speed (if you have variable pump), turn the cylinder stat down to low (this will shut down the motorised valve and push water around the heating circuit).

Right, you're talking to a plumbing newbie so could you explain that in more layman's terms (if that was possible) ??

tryitandsee said:
shut all rads upstairs off

Is that at the thermos or elsewhere. Whilst some of the downstairs radiators have "valves" in the pipe underneath the radiator none of the upstairs ones do (they're all just 2 pipes coming out of the floor - 1 at each end).

tryitandsee said:
turn the pump up to fast speed (if you have variable pump)

pretty sure it's not a variable pump - but it's difficult to tell, the pump is right up close to the cylinder and is pointing towards the tank rather than outwards.

tryitandsee said:
turn the cylinder stat down to low

tryitandsee said:
Something to do, better than watching poor old Billy mitchell.

tryitandsee · 17 Dec 2007

Sorry Adam, but I am a Layman

I don't think I can help you.

Perhaps it's time to take the telly upstairs, at least it will be warm up there. Others will hopefully explain better than me.

AdamBrunt · 18 Dec 2007

Right ....

all the upstairs rad thermos are now off and one of the downstairs rads is now working (but none of the others).

the pump is very hot to the touch (but that could be me being just a wuss !!!).

Does that sound like a pump problem or just an airlock which is slowly moving round the house ??

gas4you · 18 Dec 2007

Turn off hot water and all downstairs rads as well except one that doesn't work. Hate to say this, but shut the bypass (if you have one) in the airing cupboard just after the pump.

Pump should not be getting 'red hot' to touch though.

If above doesn't work I would personally replace the pump.

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Radiators: SORTED but now needs a 'power flush' ??

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