"Wards Signature - Gas Heating System" 30+ yrs.

What would cause a gas fired forced hot air system to fire up without the blower, then shut down. After the burner shuts down then the blower comes on. Is this normal? Any ideas what would cause this behavior? Can't replace the unit right now(No $$$). So I will have to repair or have repaired. I just want to be an informed consumer if/when I have to call for service. Many thanks in advance.
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It is typical for the furnace's burner to start first, then the blower. From what you describe, on that age of furnace, my guess would be that the fan control is either out of adjustment or shot. not really a big deal to repair. Then do yourself a favor and replace that old hulk as soon as you can. The money you save on your gas bill will probably pay for it in a couple years! Greg
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Thanks for the reply. Sounds right on. I was just playing with the Tstat. There is an adjustable arm behind the main control (this is the round heat only style stat). After a few adjustments I think it will do the trick. My father has a habit of playing with things like that, not really knowing what he has done. I do plan to replace the unit with an oil burning unit for both heat and hot water, using WVO or biodiesel for fuel. Again, thanks for the reply.
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"Thanks for the reply. Sounds right on. I was just playing with the Tstat. There is an adjustable arm behind the main control (this is the round heat only style stat). After a few adjustments I think it will do
the trick. "
The fan control Greg was referring to is the limit switch on the furnace, not the thermostat. The fan limit switch controls the temps that the plenum must reach for the blower to turn on or off.
I guess it's also possible as you suggested that someone could have moved the heat anticipator in the thermostat to an extreme setting. That apparently is what you are fiddling with. It's function is to introduce some small amount of heat to the thermostat so that it shuts off a little before reaching the desired temp. That way the remaining heat in the system brings the house to the set temp, not overshooting. At an extreme setting, you might be able to set it so that it shuts off the furnace before the blower can turn on, but I haven't seen that actually happen.
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