"jtpr" wrote in message
...
We have lived here for about 5 years and the heat has always behaved the
way it should other then an occasional frozen pipe on the second floor and
a
broken circulator.

The house has FHW by Oil, 3 zones: First Floor, Second Floor, Workshop.
For some reason we have had this odd thing going on for the past week.
The second floor is constantly hot, like 73 degrees. The first floor is
steady as it should at 68 degrees. This is with temps outside around
30-35. I have the thermostats set up to turn the heat down to 58 at night
and for all the time we have lived here the second floor would be hitting
that by the morning, just before it goes back up to 68. Now, I get up in
the middle of the night and it is still in the 70's. I even turned it off
at the thermostat, the radiators are still hot. I took the thermostat
controller right off the wall, no diff. The funny thing is if I check the
zone control on the boiler, the zone is not calling for heat, but the
radiators are always hot.

What would cause this?

Sounds as if a valve for that zone is leaking through.

I don't know much about hot water heat, but worked with lots of heating
schemes in a factory. I am guessing that there is some kind of valve for
each area of the house.

If a radiator is hot without a call for heat, then I would assume a valve is
open that is not suspose to. Check them to see if any power is getting to
it when it is not suspose to. If no power and the outlet side of the valve
is hot, then it is probably leaking.