motorised valves

[Hugh]

Can a CH motorised valve become faulty, but still be operated by the lever? - and it's the valve - not the motor which has been replaced.

Hugh

[Mike]

Did you fit the valve correctly ?

[Paul King]

So, if I read this correctly, you've gone to all the trouble of (hopefully partially) draining down the system in order to replace the valve, re-fitted the (unknown quality) motor, refilled and bled the system, and now find that it still doesn't work...

All in all, its usually (IME) the motor which burns out. This can be replaced without draining the sysyem at all.

If it *IS* the valve which is faulty, I'd have replaced the whole goddam shooting match, and have done with it!

YMMV

[Paul Heslop]

Can I ask a largely unrelated question about the same subject? In a previous email to uk.d-i-y it was suggested that to test if your motor was broke you should test to see if it had gone "open circuit" otherwise it should have a resistance of 2,500 Ohms. Well my motor seems to measure approx 200 Ohms (maybe I misread it) but doesn't seem to work. I took the motor out (but kept it wired) and turned on the system, measured 240 Volts across the motor, but nothing happens. I would assume therefore that the motor had gone. Is this correct? Why is it then measuring a finite resistance?

Many thanks for the help

Paul

[Paul King]

I *THINK* 2,500 ohms is about right for a working motor - you might have shorted turns, resulting in the 200 ohm reading you're getting, and a non-functioning motor because of the shorts. But, generally, they go open. What you *REALLY* need to do is measure how much current its pulling. No current = knackered, *LOTS* of current(Amps worth) = knackered too :( somewhere in the happy middle (and a ticking/whirring noise) = happy joy :)