Five zone house - problem with one zone

[TCass]

Hi,

We have a five zone home - two upstairs and three down. When we call for heat for upstairs all works fine - heat comes on for upstairs area only. When we call for heat downstairs on one of the thermostats there is heat both downstairs and in that same upstairs area. Looking at the valves downstairs in the latter case we can move the lever on the valve for the downstairs area easily so it is open but the upstairs valve cannot move (so closed despite the fact there is heat)

Anyone have any thoughts on troubleshooting?

Thanks,
Tracy

 

[Jadnashua]

It sounds like that valve for upstairs is stuck open.

 

[Sponsor]

 

[Dana]

What is meant by "When we call for heat for upstairs all works fine..."???

What happens when justt the other upstairs zone is calling for heat? Does the misbehaving zone get heat too, or just the other upstairs zone?

Or is it only receiving un-called heat when a downstairs zone is calling for heat?

If it's getting illegitimate heat whenever ANY zone calls for heat (the other upstairs zone, or any of the downstairs zones), the valve is stuck open, as jadnashua suggests. If it's only getting it when downstairs zones are being called it may take more information about the system to diagnose.

You use the singular "valve" , rather than "valves" in the description " ...the lever on the valve for the downstairs area.. " and "...the upstairs valve cannot move...", yet claim there are five zones. Most zoned systems controlled by zone valves are configured with a separate zone valve and thermostat for each zone. Are there really only two zone valves?