jtpr wrote:
On Thursday, March 7, 2013 3:05:58 AM UTC-5, harry wrote:
On Mar 7, 12:44 am, jtpr wrote:

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.

.... Snip ...

What would cause this?

Jim

There will be a zone control valve for each area.

... Snip ...

Thank you all for the info. I took a look and could not find zone valves
in my system, just a type of one way valve at the beginning of each run.
So I called the oil company and they sent somebody out that confirmed
this. One was bad and he replaced it, so all works now.

Thanks again.

-Jim

Umm...wouldn't a valve at the beginning of each run be a "zone valve"?