Why is the zone that is off still receiving heat?

Geist

To make a long story short, I woke up today particularly warm in my bedroom. The zone for my bedroom is on a different zone and is normally off any way because it is up stairs. The first floor zone turns on in the morning to set the temp for the day and thus its done on a timer while the second floor zone only works if you turn it on. This morning the radiator in my bedroom was warm as if the zone was on. I went to see if the feeds and returns were warm in our basement where our boiler is located and only the tube that wasn't warm was the second floor zone feed tube. The return tube was warm though.

Feeling perplexed on why this might be the case.

bmwpowere36m3

Gravity flow...? Are there check valves on the zones?

Tinman

Is there a pump or a zone valve for each zone?

If pumps, are there some sort of flow checks in place? I'm guessing yes since this is a new problem. It may not be seating entirely in the closed position. Also, is the zone pump in question getting voltage?

If zone valves, what brand? There is a way to manually open zone valves. You want to make that it's in the automatic position.

Shorted low voltage wire is a possibility.

JUGHNE

It sounds like you seldom use the 2nd floor heating? You might try to exercise that zone, perhaps a zone valve or flow-check valve is not seating and you are getting gravity flow up-stairs.
Opening and closing devices several times may get things seating correctly.