Upstairs radiators hot, downstairs not

[DJM]

A couple of upstairs radiators at my aged parents house were very cold and suspect needed bleeding. Having bled them they are now red hot - excellent.
However, the downstairs radiators are now mostly cold. Tried bleeding them and they are fine.

All the flow valves are fully open (and not changed since before bleeding any radiator). The pump is very noisy, but seems to be providing plenty of flow rate.

Any ideas what might be wrong?

 

[mcmoby69]

Blocked pipes or rad valves, what are they piped in plastic or copper? Try winding the rad valves up and down a few times, check any Trv's pins are not stuck.

Could do with more system info tbh. Sealed system, boiler, controls fitted, y plan or s plan etc etc.

 

[gasmanstu72]

turn off the upstairs ones and see if the downstairs get hot, could be airlocked

 

[DH6]

Faulty pump

 

[DJM]

gasmanstu72 - I'll give that a go
DH6 - I think the pump is on its way out (dad wont listen) but the flow does seem to be quite strong.

 

[DJM]

mcmoby69 - system is pretty basic and quite old. single thermostat, no TRVs, copper pipes. Cant remember what boiler
rad valves are old, but it would be a bit odd that all the downstairs valves failed simultaneously