A failed furnace ignition can leave you in the cold. There are a few common signs that indicate if the furnace ignition is the problem.
1. Operation Failure
The most obvious side effect of a malfunctioning ignition system is that your furnace simply won't power on. If you have turned the thermostat up and the heat still isn't coming on, it may be time to check the ignition. Most ignition systems have a starter button you can press, which will reset the ignition or light the pilot light if it has failed. If this doesn't get the furnace back up and running, then you may need to call a repair tech in to get to the bottom of the problem.
2. Cold Air
In some cases, your furnace may continue to blow air even though the ignition system is no longer igniting the fuel to warm the air. Instead of warm air, though, cold unheated air will blow out of the vents. First, verify that the thermostat is set to heat and not cool. If everything is set properly and only cool air is coming from the furnace, it is time to have the ignition inspected and repaired.
3. Failed Pilot Light
The root of many ignition issues is the pilot light, particularly on older furnaces that don't have electric ignitions. You can check the pilot light quite easily, as it should be visible as a blue flame. Flames can sometimes go out and only require relighting, but you may need to call a repair service if the pilot keeps going out. Pilot lights that burn any color other than blue, or those that are flickering, also need to be assessed by a repair technician, as this indicates an issue with the pilot light or fuel valve.
4. Short Cycling
Short cycling occurs when the furnace pops on and off more frequently than it should. It often occurs hand in hand with poor heating or the blowing of cold air. Although there are a few issues that can cause short cycling, often the issue is with a failed ignition that prevents the air from heating as it should. The furnace comes on but the house doesn't get warm. Then, the furnace shuts down to avoid running too long and stressing the fan motor, but it is forced to come right back on because the thermostat is still tracking cold temperatures. Repair is needed to fix the ignition.
Contact a furnace repair service, such as Powder River Heating & Air Conditioning Inc, if you suspect ignition issues.