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Furnace Ignition Problems? Consider These Possibilities

A furnace ignition problem is probably the most common call a heating contractor gets once the weather turns cold. While performance and efficiency issues have many origins, when the heater just doesn’t work, it’s usually a furnace ignition problem. Sometimes it’s something simple, sometimes it takes professional expertise and equipment to pinpoint why a furnace won’t ignite.

Today’s furnaces are complex units that utilize an open flame, generate high temperatures and can produce dangerous by-products like carbon monoxide (CO). It’s not the place for do-it-yourself repairs. However, homeowners can make a few basic checks to rule out some of the more simple causes of a furnace ignition problem.

  • First, the obvious: Make sure the switch on your thermostat is set to “heat.”
  • Check the dial on the furnace gas valve where the gas supply pipe enters the ignition unit. Make sure it is in the “open” position. That position is clearly marked on the dial.
  • If the digital thermostat screen is displaying an error code, write down the code and provide that information when you call the service department at your HVAC contractor. If the screen is completely blank, let them know about that, too.
  • Check the circuit breaker cabinet for a tripped breaker switch that may have shut off power to the furnace. This will appear as a switch that’s moved to the middle position between “on” and “off.” Reset the switch by flipping the switch into the “off” position,  leaving it there for two minutes, and moving it back to “on.” Even if furnace power is restored by resetting the breaker, it’s still a good idea to notify your heating contractor of the situation for further advice.
  • Check the pilot light. Do you see a flame? If not, carefully follow manufacturer’s instructions for how to light a gas heater and attempt to relight the pilot. If it won’t light, a defect or a safety interlock may be preventing proper operation. Contact your heating contractor.

For professional diagnosis and repair of a furnace ignition problem in the Fairfax area, contact us at HVAC & Plumbing Unlimited Heating & Air Conditioning.

HVAC Unlimited Inc.
Andre, arrived on time, very professional in diagnosing the issue, applied critical thinking in deterring the root cause, and executed precise precision in resolving my air conditioning issue. I have utilized HVAC twice before and the service, expertise, and overall experience are fantastic. I will continue to use HVAC and will inform all my colleagues of what an awesome technician Andre is.
Gregory - Fort Belvoir, VA
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