Central heating problem

[togauk]

Yesterday I had a plumber out to fix a leaking radiator. The system was drained and he told me to keep the heating on constant and keep bleeding the radiators. I did this all yesterday but no air comes out when I bleed them and they do not get hot. The downstairs ones do have water in as when I bleed them water comes out but nothing from the upstairs ones.

During the night I was woken by an awful screeching coming from the pump and had to switch the system off.

Anyone got any ideas what could be wrong (the plumber is away for the weekend) and does it sound like I need a new pump?

 

[Breesey]

Is it vented or sealed system? Combi? DHW cyclinder

You still have air in the system and he should come back to sort it.

Try bleeding it by loosening the screw in the center of the body.

Although the pump sounds bad it is probably OK. Though you should check that it hasn't seized. Take the bleed screwout and turn impeller with a screw driver (with system off)

 

[gas4you]

Sounds like an open vent system with the F&E empty or the cold feed blocked.

Look in the small tank in the loft first and see if there is at least 3" or so water in it.

 

[bengasman]

Anyone got any ideas what could be wrong (the plumber is away for the weekend) and does it sound like I need a new pump?

new plumber more like it. sounds like you have a feed problem, circulation problem and probably a lot of sludge and corrosion. plumber should have checked all this as leaking radiator is usually result of corrosion which often leads to all of the above

 

[togauk]

Thanks for the replies guys.

gas4you: yeah there's water in the small tank in the loft.

When i switch on only the hot water the boiler fires and the pump works ok and i can feel the pipes are hot around the pump. The pipes around the valve which switches between heating and hot water stay cold but a pipe that comes off between the pump and this valve gets hot. Not sure where that goes. The boiler stops after a few minutes or so.

 

[gas4you]

Could be a by-pass valve. Is the ch valve opening? Try it on manual setting with hw on.

 

[togauk]

I've done a temporary fix by filling up the system via the towel rail! I've bled all the radiators and turned the system back on. All radiators are now fully hot. I guess this confirms that it is a blocked cold feed which I still need to get sorted. Presumably it's due to corrosion, but how does this happen as from what I understand the water isn't circulating round the cold feed pipe but just topping the system up as and when it's needed. I would have expected any sludge to collect in another part.

Thanks to everyone who answered my post, I wouldn't be sitting here nice and warm without your help!