Zone valve: jumps out of override position

[mike004]

Can a motorised zone valve, locked into override position, "jump" out and return to the default position?
When I set the valve into override, it works as expected. I get HW + CH from the boiler.
But when I turn off the boiler, the valve lever seems to return to the default position.
Surely the lever is physically locked into position when you move it into the override position?

 

[denso13]

Some automatically release, return to default, when power is applied/disconnected.

 

[Exedon]

As above honeywell valves un latch when powered up.
Danfoss and eph stay open and also make the micro switch in manual position.

 

[Kenny Andases]

Judging by the description, this is very similar to the normal behavior of a zone valve with a spring return, when you put it in the manual or working position, it holds only as long as there is power or a control signal, and when the boiler turns off or the power goes out, the actuator simply releases the mechanism and the spring returns it to the default position, so it is not necessarily a breakdown but rather the design of the system, but if it turns sharply or unstable, then it is worth checking whether the valve stem itself is not stuck and whether the actuator is properly seated in the seat, because sometimes the problem is not in the electricity but in the fact that the mechanics are wedging due to scale or wear, my advice is simple: check whether the valve itself without a drive moves smoothly and does not get stuck under the load of the system and if there is any doubt, it is better to remove the actuator and test it separately to separate the mechanics from the electricity, here is a useful channel where such things with HVAC and valves are normally disassembled [https://www.youtube.com/@WordOfAdviceTV](https://www.youtube.com/@WordOfAdviceTV)

 

[mike004]

My zone valve has been in the override state for over 10 years.
But near the valve, in an old cardboard box, is what looks like a motor!
Could the zone valve have been installed without a motor in "override mode only". And with the passing of time, the override position will not hold?

 

[gas112]

if its a metal lever put a little bend in it that way it will usually catch again on the way back