3 times in the past month I have noticed my house seems a little cool. I
check the thermostat and it is set for 73 but the temp is 70. The
thermostat says "Heat on" but the furnace is not on. If I just switch
the thermostat off then back on the heat comes on and the house warms
up. I have a Honeywell electronic thermostat. Is this a termostat
problem or a furnace problem? Once I just took the thermostat off the
wall (it sort of unplugs so you can change the batteries in the back.)
and plugged it back in and the heat came on. I have seen igniters fail
before but from what I can remember once it fails the furnace won't come
on at all. Any ideas on this?
There might be an anticipator circuit that you can play with. There is in my
Your going to need a manual for your tstat and a real good understanding of
your furnace. Might be worth a call to the local HVAC tech.
I doubt that the batteries have anything to do with it, but they are cheap
to do if you do not remember when you last changed them.
It seems that when you interupt the circuit temporarily by pulling the
thermostat or turning it off, the furnace goes on. My first thought is that
the mechanical jolt you're giving the thermostat is temporarily tightening a
loose wire somewhere in the general area. Have you checked all your
connections, upstairs and down, to make sure they're tight and uncorroded?
Or maybe the contact points in the thermostat which complete the circuit are
dirty or impeded by dust and need a slight jolt to make full contact.
The second thought is that restarting the current flow causes an electrical
spike which is enough to trip a faulty relay.
My Honeywell electronic thermostat always reads the same or
at most 1 degree lower than the setting, which means that
the thremostat regulates the temperature at the thermostat
within one degree. The only time it ever reads more than
one degree difference is if I manually turn it up and the
time it takes for the furnace to come on depends on the
amount you turn it up. It may wait 2-3 minutes for a 1
degree change but a 4 degree change is immediate, so if I
want it on and it doesn't come on immediately with 1 degree
increase I boost it up 5 degrees, it comes on, and then I
lower it to where I want it.
I think it's your thermostat, if it normally is within one
Andy Arhelger wrote:
Sometimes when it is really cold my thermostat reads 18 or 19c when it is
set at 21. Perhaps you have been experiencing cold weather and your system
isn't keeping up? 19 is okay with me considering it is -25 to -30c outside.
Or maybe your thermostat is on a cold wall?
I seem to recall a thread like this in the past where the OP had the
same problem and ended up changing the batteries even though the
indicator to do so was not lit, try that to see if it works, other
than that, I'm just a spectator so keep up with the thread.
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