Grundfos Alpha 2 - Rads cold downstairs

[Staceylc]

I'm hoping someone can help. British Gas replaced our old pump with a Grundfos Alpha 2 a few months ago. It's been fine until now. We've been running it in auto adapt but in the past couple of days it's not warming the downstairs radiators at all. It was showing that it was running at 5w, which isn't enough. I've changed it to constant II but it's still freezing, I did put it up to III but it went up to 45w and made a loud noise so put it back down to II. I don't know what setting it should be on as I know nothing about heating systems and everything I've read makes no sense.

Thanks

 

[muggles]

Did the downstairs radiators get hot when you put it on III?

 

[terryplumb]

Stacey try this please , if you have thermostatic radiator valves turn them to off on all upstairs rads and see if downstairs rads heat up. If you know how to bleed air from a radiator ,bleed all downstairs rads .

 

[Staceylc]

Our downstairs radiators are now hot on setting III. I'm just paranoid it will overwork and something else will go wrong. We're going to bleed the radiators tomorrow and see if it makes a difference when I change it back to II

 

[terryplumb]

Have you achieved this Just by changing pump speed alone ?

 

[Staceylc]

Have you achieved this Just by changing pump speed alone ?

Yes. Not sure why it suddenly stopped working in auto adapt

 

[terryplumb]

Were you having similiar issue before the new pump was fitted , is that why it was fitted ?

 

[Staceylc]

Were you having similiar issue before the new pump was fitted , is that why it was fitted ?

Apparently so. He said the old pump had black water in it so changed it but didn't explain how the settings work on it.

 

[mcmoby69]

Get them back, probably now advise a powerflush costing 9k next.

New pump didn't cure original fault, misdiagnosed.