"Frontier" wrote in message
...
I am having trouble with keeping the heat on in our home. The heat will
come on, as normal, but the blower and heat will shut down before reaching
the temperature at which the thermostat is set and the thermostat
continues
to flash "heat" as if it thinks the unit is still on. This normally
happens
when the outside temperature gets below about 20 F.

Thinks? No..its telling the unit to keep running. The stat only knows on,
and off..thats ALL it knows.



We called in the heating people and they determined that the valve was
shot
from doing a test that showed that little gas was getting to the furnace.
This was right after Thanksgiving. We had a warm spell and it seemed to
be
working OK, but the last few days have been colder and it is happening
again.

Wait...you mean you were told you had a problem, left it, told what was
wrong and now you want answers from people that HAVENT seen it?


The odd thing is that sometimes it will run for hours and work fine, as
happened last night. I got up during the night to find the temperature in
the house at 64. I turned the heat off (to reset the thoermostat) and
back
on and it ran for a number of hours.

Again....you were told what was wrong and now you want answers?

Ok..
Is it a SV series valve?
If so, its shot, and thats a simple reply...if not...its screaming high
limit...but....you have not anywhere CLOSE to enough information to even
guess at the problem.
You want to guess how many different gas valves there have been used over
the last 40 years? How about overlimit designs?




Just a few minutes ago I turned it on after replacing the filter, and it
ran
for about 10 minutes before shutting off, with "heat" still flashing on
the
thermostat.

Any ideas?

Call someone that can check it out, SEE what you have, verify and dupicate
the problem, and isolate the problem.
We cant do that over the net.