System: gravity hot water cylinder (About seven years old) with 1 rad. Pumped central heating. 2 rads upstairs. 4 rads downstairs. Baxi Burmuda back boiler. (about six years old)
Fault: The rads downstairs one by one stopped working over about six weeks.
Remedial actions so far: Raised header tank. Flushed out all rads. De-sludged pipe-work. Pushed mains water through pipe-work to prove conductivity and push out any residual sludge.
Vented system with boiler off. (Also replaced 1 rad downstairs)
Results:4 downstairs rads not working.

Alan Miah, November 2006

sounds like the pump!

me, December 2006

check pump

simon, November 2006

have you checked your pump, just cause you can hear it don't mean it pumping, it may have no fins left on the pump. also raising your tank is a waste of time thats just a header tank. don't need gravity pressure like your cold storage for your hot taps.it can be just above your copper tank still work the same

hi-spec plumbing, November 2006