Gas Furnace won't come on:
This is a very common and usually simple problem. Many times the service technician is dispatched only to find a simple problem that the homeowner could have fixed himself. A list of possible causes:
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Thermostat not set properly
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Emergency or shut-off switch turned off (usually a red button around the burner area near the gas valve if it keeps tripping you need a service tech.)
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Blown fuse in the panel box (replace both fuses)
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Circuit breaker tripped or off- (sometimes a breaker will trip but it won't move, always turn off and back on to reset even if looks on)
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Disconnect turned off next to unit look like a light switch - (this is one of the biggest things we see usually someone turn off by accident.)
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Condensate pump or safety switch opened at blower or furnace unit (check pump, usually located near indoor unit)
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Unit "locked-out"- (reset by turning off then turning back on, sometime you have to turn off power and back on. If problem persist then you need to call us.)
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If your unit is over 10 years old check and see if has a pilot to light if it does the gas valve will have a pilot button on it. If Pilot is out try relighting.
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Be sure gas is on at the meter, gas line at furnace and gas valve.
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On 90% furnace that vent from the house with PVC check to make sure that nothing is obstructing the opening of the pipe
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Faulty thermostat
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Faulty time-delay relay
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Faulty thermostat wire (sometimes damaged by animal or lawn mower)
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Safety device tripped - (low pressure, low temp, high pressure, high temp...)
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Faulty control module
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To many to list on a gas furnace
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