Downstairs radiators cold

[Last Triumph]

Having removed the bathroom radiator today and re-filled the CH system, the downstairs rads don't get hot, they stay stone cold.

I've bled every rad in the house 3 times and there is no air in any of them.

Also, to add insult to injury, the pump has now stopped working. It is scalding hot het the pipework 6" either side of it is fairly cool.... Could it have an air lock and overheated / switched off?

It is still very hot 2 hours later and won't switch back on leaving me with no heating.

So, why would the downstairs rads be cold when the upstairs ones got nice and hot even after bleeeding and what can I do about it, and any clues on the pump?

Ta

 

[twgas]

if the pump's not working the upstairs can get hot through gavity circulation, but downstairs wont. new pump time i think

 

[Last Triumph]

Okay, further investigation....

After a while, the pump works again and the boiler fires up..... for about a minute then the boiler shuts off again.

It is as if there isn't enough flow through the boiler and as soon as the water in the boiler reaches a certain temp, it shuts down, were if the water was flowing through it, it would stay lit and give me nice hot waer.

Rad issue can wait. Main problem is that I now don't have any hot water!

What would stop the flow? An air lock? If so, how do I correct this?

 

[twgas]

have you bled the pump?
is the pump making much noise?

 

[Last Triumph]

Pump is fine and makes it's usual hum.

However, I ve just switched the heating on again and stayed by the boiler this time to see what happens.

Shortly after firing up, you can hear a sound like a kettle bloiling which tells me there is an air lock in the boiler?

If this is the case, how do I get rid of it?

 

[twgas]

most boilers have pipes coming off top of boiler so air-locks are not usually a problem in boiler itself, if however the pipework runs down, away from boiler then an airlock is quite likely, should be air bleeds if the latter.

any chance of some pics

 

[Last Triumph]

I think the problem is with the pump.

It was set on position 2 yet nothing was happening. I switched to position 3 and it very slowly started to gather speed.

After about 2 mins it is going quite fast, but if I turn it down to pos 2 or 1 it just stops.

I think the pump is finished.

Now it is grinding away on pos 3, the downstairs rads are back on line and the boiuler has stayed lit.

Flow was too slow after all.

Thanks everyone. New pump tommorrow!

 

[redvanman]

have you cleared the air locks from the bleed points, these are sometimes at the top of vertical pipe runs open them with a screwdriver or bleed key. another thing you can try is turning all the upstairs rads off then all the pumps force is pushing to the rads that are air locked