When your furnace rumbles at night, it is most likely because it is working overtime to heat your home during Maryland’s frigid fall and winter nights. This can cause a furnace breakdown or failure. To help you diagnose furnace problems, here are a few of Warner Service’s common problems and solutions:

Problem: Your furnace is not receiving power.


  1. Check the state of your natural gas furnace’s circuits at the entrance of the unit.
  2. Check the thermostat. The majority of furnace failures are caused by a common faulty thermostat, so increase the temperature by 5 degrees.
  3. Check that the second power switch is turned on for back up.

Problem: Your furnace needs to be reset.

Solution: Typically there is a “reset” button on natural gas furnaces near the motor housing. Turn off the furnace entirely, and wait 30 minutes for it to cool down then press the “reset” button. If the furnace does not reset immediately, repeat the procedure two more times.

Problem: The furnace is turned on, but the heat is not flowing throughout the house.

Solution: This could be the result of old age in which case you need to call a professional to install a new furnace. It could also mean that your furnace’s distribution system is having issues. This could be a simple fix by changing dirty and dusty HVAC filters or you may need to contact a professional for a more serious, permanent solution.

Problem: The pilot light is yellow instead of blue.

Solution: This means that there is too much carbon monoxide created by your furnace, which could be highly dangerous. If you or your family experiences nausea, dizziness, burning of the eyes or throat or flu-like symptoms, open all of your windows and call a gas company’s emergency number to get a technician to your home immediately.

Problem: The furnace’s pilot light has gone out.

Solution: This light warms the thermocouple, which allows for the gas flow to ignite the pilot light. Once the pilot light ignites, the furnace heats up. To reignite the pilot light, carefully follow these steps:

  1. Make sure there is no leakage or other spills surrounding the furnace.
  2. Turn the knob on the gas valve to “pilot.”
  3. Press down on the knob, which should light the pilot, and hold it for 1 minute.
  4. Release the knob.
  5. Turn the gas valve into the “on” position to fire up the furnace again.

Problem: There are cracks in your furnace’s heat exchanger.

Solution: This is caused by wear and tear, old age (most heat exchangers are designed for use between 15 to 18 years), dirty air filters/lack of airflow and chemical reactions. There is nothing homeowners can do to stop cracking once it starts, but you can prevent cracking through yearly maintenance check-ups and/or replacement.

Winter will arrive in the next few weeks, and it is vital that you and your family stay warm during the season. To do this, your home needs a properly functioning furnace. To keep your furnace in tip-top shape (and to save money on unnecessary repairs and replacements), you should schedule yearly maintenance check-ups and perform a do-it-yourself inspection every few weeks.

During these inspections, if you find that your furnace or any of its parts have the problems listed above, follow the proper solution guidelines or contact a professional, such as Warner Service, immediately.

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