Downstairs Rads luke warm, upstairs fine, single pipe, CB24

[eccoboy]

Hi, I need a spot of direction folks.
I have an Alpha CB24 combi on a single pipe system in a three bed semi with loft conversion. The upstairs rads get lovely and hot but the downstairs rads are barely warm at all.
Is this likely to be sludge in all the rads downstairs or a pump issue?
I'm happy to take the rads off and flush them out or replace the pump, just need a heads up!

Any help, greatly appreciated folks, it's getting a bit cold now!

Cheers Ben

 

[Slugbabydotcom]

It could be sludge or a failing pump or some other restriction such as a partly open isolation valve but the main cause of your problem is likely to be that you have a one pipe system. Look into changing it into a two pipe system or for now a flush and Magnaclean would be a good start to getting to the bottom of the problem.
Usually if the pump is the culprit it tends to become noisy

 

[eccoboy]

Hi thanks for your post, I've just taken off one of the rads and jetted it through but to be honest there was little in terms of sludge at all so I have to take from that the the other rads are the same (same age, same floor)
Conversion to twin pipe isn't really an option for me at the mo....

What should I take a look at next? You mention flushing the system (do you mean drain down and pass water through it to an external spot?)

Cheers Ben

 

[eccoboy]

The pump was slightly noisy but to be honest I think I'd gotten used to it. Replaced the pump with a used one from eBay for £25 and it's amazing. I've never known the rads get so hot so maybe it's been on its way out for years. It really is amazing the difference it's made, tremendous.

Cheers Ben