Best way to test a motorised valve?

[Dis Manibus]

Being a mean old sod, this is the time of year when I turn the central heating off at the timer; and just leave the hot water switched on. However, the radiators are still getting hot. I'm assuming that the motorised valve is no longer shutting off properly, but I'd like to be 100% sure, before I start buying things. I can think of a few ways I might test it (switching some other components on and off, and seeing how it reacts), but I was wondering if there is a standard way of testing these things?

[Bob Minchin]

Feel the pipe either side to judge if water is flowing through. If it is, remove the motor head and see if the valve can be moved manually. Once the motor is off you can see if turning the heating circuit on and off makes the motor run or not.

I've been looking at honeywell valves recently for a new install and buying them on ebay. Not only are replacement heads available but also replacement motor/gearboxes for less than £10. The motors on the honeywell look trivial to change.

hth

Bob

[Peter Parry]

On more recent ones, certainly. Older ones had a one piece unit where the head cannot be removed in situ without water pouring out everywhere (as I discovered!).

[charles]

must be a lot older. Mine which were 1988 vintage have removeable motors.

[dennis]

They are, and I have replaced the microswitches too. A crimping tool can be handy to connect the wires.

[Man at B&Q]

Turn the heating back on and check that the valves operate as expected in response to the timer setting and thermostat. You can usually hear them moving or watch the manual lever move.

MBQ

[dennis]

I doubt if you will see the manual lever move. They don't on any of the ones I have.

[Man at B&Q]

Then you doubt wrongly.

They have done on all the ones I have ever had.

MBQ

[Andy Champ]

They don't move on mine, and I've never had one where it does. The lever has its own spring. You can however tell what position the valve is in by pushing the lever.

Andy

[Graham.]

It's a good job too, mine are about 35 years old, and don't have removable heads. Wet parts perfect (soft water), each has had new micro switches and motors. Motor flex connections were originally just twisted with a wire-nuts, I replaced them with single choc-blocks.

[Graham.]

I agree the lever does not normally move, but the spring isn't on the lever itself, it's on the actual valve.

If the valve is open the lever is free to move, no return spring. if you were minded to move it to the open position and then de-energised the motor then the lever *would* move back to the closed position by the operating cam.

That's for two port Honeywell's.

[Dave Liquorice]

Not on my two port Honeywell valves in normal use either. If you move the lever into the latched "filling" position it will unlatch and spring back to its rest position when the valve is motored open.

I did have a three port valve that did have a lever that moved but I don't think that was Honeywell and was three port. Mind you I don't think the OP has said if his valves are two or three port...

[Dis Manibus]

Thanks, everyone. I'm going to conclude that it's not well, since it just sits in mid position, whatever inputs are present. Seems odd, because I'd have thought the spring would pull it to one side, but it doesn't.

I'm going to spend a bit of time trying to find out which part is broken. The genuine replacement head costs at least 60 on eBay. Or, there's a third-party one for about 35. Or, there is a replacement motor for about

1. As I said, I'm a mean old sod, so I'm happy to spend some time on it.

[The Natural Philosopher]

same here. They don't move

[dennis]

If you don't engage the stop that's there to keep the lever open. The lever is there to open the valves for flushing and normally has a notch or similar to keep it open against the spring return.

[Man at B&Q]

This one

"Manual lever and valve position indicator".

The lever and indicator are the same piece of plastic. Same on all the zone valves I have had.

MBQ