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CBhvac
 
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Default Heat Keeps Shutting Off


"Stormin Mormonn" wrote in message
...
Sure would be nice for me to be there, and watch it doing its job.


You might learn something.



First thing I was thinking was heat anticpator. Thermostats turn off the
heat at the furnace a little early, to give the furnace a chance to blow

the
heat out of the furnace. Otherwise it would get to 71, and there would be

a
lot of heat left in the furnace. But not 4 degrees worth.


Umm.....wanna bet?



The question about "cycling on fan limit" asks if the furnace is hot when
the blower turns off. It should run the blower till the furnace cools

down.

So..it it the upper limit? The blower door limit? The burner limit? What
limit?
Speak Chris....we are all waiting..


Sounds like it's time to call a heating guy. From your answers, we're not
speaking the same language here.


I AM a heating and air guy, and trust me....no one understands you.



--

Christopher A. Young
Jesus: The Reason for the Season
www.lds.org
www.mormons.com


"Frontier" wrote in message
...
I'll answer these to the best of my ability.

When it's cold in the house adn calling for heat, is the T-stat sending

the
call for heat to the furnace? Yes, I believe it is. The "Heat"

indicator
will come on on the thermostat, the furnace will fire up and the fan will
start.

Is the furnace / heat exchanger hot? If you mean are we getting heat from
the vents, yes. We get heat from the vents for five to ten minutes.

Is it cycling on high limit switch? Again, I'm not sure if I'm replying
correctly. The furnace shuts off before it gets anywhere near the
temperature we have set on the thermostat (i.e., shuts off at 67 when it

is
set at 71). Plus, the thermostat continues to indicate that the heat is

on
even though it is not.

Are the burners turning off? I believe they are.

Does the air
coming out of the registers feel like it's blowing the usual ammount?
Interestingly, when we are actually getting heat, it seems like it might

be
slightly less powerful than in the past. Once the heat stops the blower
also stops.

Thanks for the help.

Roger


"Stormin Mormonn" wrote in message
...
The question here is whether the furnace is hot when it shuts off

(blower
problem) or if it blows till it's cool (so the limit switch is OK, but

the
burners are not staying on). Or maybe nothing stays on (thermostat or

low
voltage problem).

We really don't have enough information to be sure, at this point.

When it's cold in the house adn calling for heat, is the T-stat sending

the
call for heat to the furnace? Is the furnace / heat exchanger hot? Is it
cycling on high limit switch? Are the burners turning off? Does the air
coming out of the registers feel like it's blowing the usual ammount?

--

Christopher A. Young
Jesus: The Reason for the Season
www.lds.org
www.mormons.com


"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.

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.

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.

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?