Please help!!! Hot rads downstairs; cold upstairs

[RustyDave]

I've had a flick through previous threads but none of them seem to cover precisly my set of circumstances. Grateful for any thoughts or suggestions. Here is what's wrong:

- I have a back boiler (Baxi Bermuda) system and my pump is situated next to my chimney breast in the living room
- All of my radiators work downstairs (pretty hot)
- None of my radiators are even slightly warm upstairs (nor are the pipes leading into the rads)
- I have tried bleeding all of the rads
- I have tried turning all of the downstairs rads off to see if it would balance the system somehow but the upstairs still don't even get partially warm
- Help!! My girlfriend is starting to lose patience with me!

 

[ollski]

is the pump spinning?

 

[RustyDave]

Thanks Ollski. I'll check this out tonight. Presume it's okay to release the central screw so long as I switch the CH off at the controller.

 

[breezer]

if you do that it wont spin.

believe it or not you can undo the centre screw with it still running (so i read on these forums)

 

[kevplumb]

is there water in the header tank?

 

[wilhelm]

mmmm..well ive had the case of the spinning pump.......well thats ok ????
wrong , only to have someone else find that the shaft was spinning, but the impellor was not..... what a drag, made to look a buffooon yet..again try playing with the speeds and see if audio is different?

 

[RustyDave]

Morning all,

I checked my pump last night. It is a Myson Compact. I unscrewed the central black screw and I could immediately tell that the pump was working (the screw was rapidly vibrating). The speed is already set to 3.

So then I took a visit to the loft. The feed and expansion cistern is half full (or is that half empty...?). I pushed the floating ball down and new water started to fill the tank, so I don't think anything is blocked.

The added complication now is that we don't have any hot water in the taps. I tried turning off the CH (which is still only working downstairs) and it hasn't had an impact. This is really puzzling me now because a week ago (before I even turned the CH on) the hot water was working just fine.

 

[kevplumb]

are the valves open

 

[RustyDave]

Do you mean the valves either side of the pump? Is so, yes.

 

[kevplumb]

are both valves open on the rads that wont work ?

 

[ChrisR]

I pushed the floating ball down and new water started to fill the tank, so I don't think anything is blocked.

No no no,
no no no,
NO! You missed the point. If the feed pipe from the header tank to the system is blocked - very common - then your system would be short of water, so the downsairs rads would be full of hot water and your upstairs one full of room temperature air. If you bleed the upstairs rads, does water come out?

 

[RustyDave]

Yes, valves on all of the radiators are definitely turned on, both supply and return!

Also, when I bleed the upstairs rads water does come out.

I had someone come and look at it this morning, and they said that it needed a power flush - he quoted me £450+VAT for this - does that sound about right?!??

 

[RustyDave]

Why do two sets of plumbing profesionals give such differing opinions?

I was dubious about the power flush idea (expense, sounded a bit of a gimick and none of my family/friends had ever even heard of one). So I got another plumber to come and have a look. He said power flushes arent even guaranteed to work (!) so he suggested replacing the pump. We were delighted to find that this solved the problem of cold upstairs rads and has continued to work fine for the last week or so

But last night a new problem emerged Rads are still fine but no HW anymore. I can feel the pipes leading from the boiler to the tank in the loft and the feeder pipe doesnt get hot anymore.

Was the first plumber right after all? Or am I right in thinking that a silt build-up should not cause a problem on the gravity-part of the system (ie. the hot water loop) ??