I had always assumed that when I manually opened one of these valves that the 'boiler ON' microswitch was activated.
I seem to remember manually driving my old heating system that way once.
Looking at ones I have fitted now seems that the manual lever DOESNT move the cam far enough to close the switch.
I guess when the motor controls it, it will.
Yes?
TIA
Yes, in most models. When you pull the motors manual lever across it hits the microswitch and switches on the pump/boiler, then moves back to wedge itself in the recess in the lever slot.
Yeah. Annoying isn't it! The instructions claim it is only an aid to refilling/flushing. You can always add a manual switch (i.e. light switch) across the microswitch terminals if you require a manual override to get the boiler going.
Christian.
If you are going to that extent, juts replace the valve motor head. Off the shelf everywhere.
My new ones don't, but some older ones I came across the other day do.
Puzzled the heck out of me.
What make?
The ones I've come across, the manual lever always leaves it in the mid-position (for a mid-position valve).
I can confirm that with a standard 'Honeywell type' zone vale the microswitch DOSN'T operate when the valve is manually operated but does when electrically driven. (Got eight of them in my system )
Andrew Mawson
Same with Myson Power Extra 2 port. No switch operation.
Christian.
I haven't a clue. They were in teh dark dingy recesses of someone elses hot cupboard.
We were trying to work out why teh central heating wasn't working.
Eventually diagnosed to the master thermostat on the hall being behind a picture immediately above a table lamp kicking out a lot of watts.
The Horstmann type zone valves (compatible with Honeywell - available from screwfix) do however close the switch on manual operation.
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