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
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.
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
I haven't a clue. They were in teh dark dingy recesses of someone elses
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.
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 <g>)
HomeOwnersHub.com is a website for homeowners and building and maintenance pros. It is not affiliated with any of the manufacturers or service providers discussed here.
All logos and trade names are the property of their respective owners.