Water cut off, now downstairs radiators don't work

[terryplumb]

Could be pump ,or the motorised valve on c/heating isnt fully opening ,and always assuming the system is full of water and no air.

 

[ianmcd]

Ok it's starting to make sense. The pipes to the hot water tank weren't hot when the heating was on with no call for water. So I'm trying to take off the 4 Allen bolts on the pump but they are very stuck at the moment

never usually hard to slacken off with the correct tools, pros use a T bar but lots of other tools suitable for the job

 

[HateMyHeating]

So I've replaced the pump, the old one didnt look like it was in a terribld state but it's a bit rusted up. The new pump seemed like it was doing the trick but ... It hasn't fully. More rads get hot but not all, and now the boiler has started kettling at times. I'm going to drain the system, add some x800 and see if that changes things... Hopefully it'll help!

 

[breadnbutter]

did you check the pump gate valves are clear, I usually stick a bucket over them ,open one up at a time, makes sure there clear.
that pump impeller is crusted, but hard to see impellers, they look clear but to dark pic to see.
is pump set to 3.
x800,leave it for a week, then fully flush out.

 

[HateMyHeating]

Thanks for your help everyone. Just to hopefully close this off, a plumber came out as the x800 hadn't helped much. He took the connector for the expansion/cold/hot pipes off as he thought it might be blocked. And he was very right! (see pics)

Hopefully this thread helps some other DIYers; check how quickly the pipe from the boiler going to this connection and the pipe coming from it to the pump get hot. If you can tell there's a difference it could indicate that's blocked. And it could be significantly blocked!

That seems to have solved the problems of kettling and rads are getting hot now, all except one which should be easy enough to deal with given everything I've learned over the last few weeks.

Thanks everyone!

 

[breadnbutter]

a choked up air separator.

 

[dilalio]

Thanks for your help everyone. Just to hopefully close this off, a plumber came out as the x800 hadn't helped much. He took the connector for the expansion/cold/hot pipes off as he thought it might be blocked. And he was very right! (see pics)

Hopefully this thread helps some other DIYers; check how quickly the pipe from the boiler going to this connection and the pipe coming from it to the pump get hot. If you can tell there's a difference it could indicate that's blocked. And it could be significantly blocked!

That seems to have solved the problems of kettling and rads are getting hot now, all except one which should be easy enough to deal with given everything I've learned over the last few weeks.

Thanks everyone!

This is why you can't beat eyes on site.
If I'd been there and seen you had an AS, I would have been wrinkling my nose at it