Rattling Central Heating Pump

[matspring]

I recently decided to do something about the increasingly noisy rattling sound coming somewhere from my Open vented central heating system.

So my system rattling and moaned, as a first point of call I cleaned, drained and refilled the system, adding new Inhibulator - firing water back up through the system to clear an air blockage. This initially appeared to have solved the problem, however the rattling returned (moaning fixed!).

I've bled all radiators (little air left) and also the pump (grundfus UPS 15-50).

I'd assumed that the rattling was coming from the pipes however following my ears have pinpointed the noise to be coming from the pump in the airing cupboard and/or the Honeywell silver box (auto / man open settings with a slide switch??) located about 10 inches above.

The pump is currently set at setting 3. I've just changed it to setting 2 and the noise is reduced and when at setting 1 the noise appears to disappear all together.

Although this may have fixed the noise, I've concerned that the water will not be pumped around the system sufficiently.

Does this sound like the pump is ready for the bin? Will my pump be OK at setting 1?

Any help is appreciated, thanks

 

[Burnerman]

Its more than likely that the pump is about to draw its pension....
If the rads are cooler than before, or some rads aren't warm the pump speed needs increasing.
Pumps are easy enough to replace....so long as the valves either side are working and can be turned off. If they can't, then its a drain down, I'm afraid.
John

 

[matspring]

Thanks for the info

I guess the valves can seize up over time can they and can't be shut off?