furnace repair

York is Getting Cold, but My Furnace Wont Turn On

Troubleshooting your furnace might feel like an overwhelming chore when your heat won’t work. But it doesn’t have to be like that.

There are a few fast, reasonable fixes you can do by yourself to prevent a furnace repair call.

If your furnace won’t turn on, won’t stay on or won’t ignite, try the troubleshooting list below before calling an HVAC professional.

If you find you need help from a professional and live in York, Strine's Heating & Air Conditioning can assist you. We repair most brands of heating systems.

If you need a new heating system, we also provide furnace replacement in York.

While you’re chatting with us, consider a routine furnace maintenance plan from Strine's Heating & Air Conditioning that might help you avoid repairs in the future. We can tell you how often your furnace should be inspected by one of our NATE-certified experts.

Use our easy guide below to get to work on troubleshooting your furnace. Most of these steps don’t require mechanical skills.

Steps for Furnace Troubleshooting

Check the Thermostat

To begin, make sure your thermostat is signaling your furnace to start.

If you have a digital thermostat:

  • Change the batteries if the screen is blank. If the digital screen is jumbled, the thermostat may need to be replaced.
  • Make sure the switch is set to “heat” instead of “off” or “cool.”
  • Ensure the program is set to the correct day and time and is set to “run.” If you’re having trouble overriding the program, set the temperature by using the up/down arrows and press the “hold” button. This will cause the furnace to ignite if thermostat programming is causing a problem.
  • Increase the temperature setting to 5 degrees warmer than the room temperature.
Digital Thermostat

If your furnace hasn’t turned on within several minutes, make sure it has power by toggling the fan switch from “auto” to “on.” If the fan doesn’t start, your furnace could be without power.

If you have a smart thermostat—like one made by Nest, Ecobee, Lux, Honeywell or Bosch—troubleshooting is very model-specific. Take a look at the manufacturer’s website for help. If you still can’t get your Wi-Fi thermostat to work, contact us for assistance.

Lennox Smart Thermostat

Examine Breakers and Switches

Next, you will need to check if your breaker and furnace switch are on.

  • Look for your house’s main electrical panel. If you don’t know where it is, keep an eye out for a gray metal box in your basement, garage or closet.
  • Make sure your hands and feet are dry before touching the panel or breakers.
  • Look for the breaker labeled “furnace” or “heat,” and make sure it’s switched “on.” If the breaker has tripped, it will be in the middle or “off” position.
  • Using one hand, firmly switch the breaker to the “on” position. If the breaker immediately trips and pops back to “off,” don’t try to reset it and contact a professional from Strine's Heating & Air Conditioning at 717-383-4479 right away.

Regardless of your furnace’s age or brand, it has at least one standard wall switch located on or by it.

  • Make sure the switch is flipped up in the “on” position. If it was turned off, expect your furnace to take up to five minutes to start. (If you don’t know where to find your furnace, look in your basement, garage or utility closet. It could also be in a crawl space or attic.)

Replace Your Furnace’s Air Filter

When it comes to furnace issues, a dirty, clogged air filter is regularly to blame.

If your filter is too dirty:

  • Your furnace won’t keep heating your home, or it could overheat from reduced airflow.
  • Your energy bills could be higher because your furnace is turning on too often.
  • Your furnace could stop working too soon because a dirty filter causes it to overwork.
  • Your furnace can lose power if an extremely dirty filter causes the breaker to trip.

Depending on what make of furnace you own, your air filter will be inside the blower compartment of your furnace, an attached filter case or wall-mounted return air grille.

Replacing a furnace filter

To replace your filter:

  • Turn off your furnace.
  • Pull out the filter and hold it up to the light. If you can’t see light through it, get a new one.
  • Insert the new filter with the arrow pointing toward the furnace to avoid damage.

Flat filters should be replaced every month, while pleated filters should last about three months. You can also buy a washable filter that will last about 10 years. If you have children or pets, you may have to put in a new filter more often.

To make the process easier in the future, use a permanent marker on your furnace housing or ductwork to show the airflow direction and filter size.

Examine the Condensate Pan

Otherwise known as drain pans, condensate pans capture water your furnace removes from the air.

If water is leaking out of your furnace or its pan has standing water in it, follow these steps.

  • If your pan has a drain (look for a PVC pipe), check that it’s clear. If it needs to be drained, use a special pan-cleaning tablet you can buy at home improvement or hardware stores.
  • If your pan has a pump, inspect the float switch. If the switch is stuck “up” with liquid in the pan, contact Strine's Heating & Air Conditioning at 717-383-4479, because you will probably need a new pump.

Peek Inside Your Furnace

If malfunctions persist, peek inside your furnace’s plastic window to check the status of the blower motor. Depending on the model, the light could also be mounted on the outside of your furnace.

If you see anything except a steady, colored light or blinking green light, call Strine's Heating & Air Conditioning at 717-383-4479. Your furnace may be communicating an error code that needs professional assistance.

Clean the Flame Sensor

If your furnace tries to start but turns off without blowing heat, a dirty flame sensor could be responsible. When this happens, your furnace will attempt to start three times before a safety feature powers it down for about an hour.

If you feel comfortable with opening up your furnace, cleaning your flame sensor is something you can do yourself. Or, one of our HVAC professionals at Strine's Heating & Air Conditioning can do it for you.

If you want to clean the sensor yourself, you’ll need:

  • A 1/4” hex screwdriver or wrench
  • Piece of light grit sandpaper, steel wool or emery cloth
  • A dry, clean paper towel

Next:

  • Shut off the furnace’s power by using its wall switch or breaker. If your gas valve is not electric, you will need to shut off the gas as well.
  • Remove the furnace’s front panel and follow the wire to the flame sensor.
  • Unscrew the rod and use your sandpaper, steel wool or emery cloth to gently rub the metal rod.
  • Wipe off the rod with a paper towel.
  • Remount the sensor.
  • Replace the furnace doors.
  • Turn the furnace’s power back on. It may run through a sequence of checks before continuing normal operation. If your furnace doesn’t turn on, the sensor may need to be replaced or something else may be wrong. If this happens, contact Strine's Heating & Air Conditioning at 717-383-4479 for assistance.

Relight the Pilot Light

If you have an older furnace, the pilot light could be out. To relight it, find the instructions on a label on your furnace, or follow these steps.

  • Look for the switch on the bottom of your furnace labeled “pilot,” “on” and “off.”
  • Turn the switch to the “off” position.
  • Wait at least five minutes to avoid possibly creating a fire.
  • Turn the knob to “pilot.”
  • Press the “reset” button as you bring the flame of a long lighter to the pilot light opening.
  • Release the “reset” button once the pilot light is lit.

If you have followed the instructions twice and the pilot light still won’t light or stay lit, call Strine's Heating & Air Conditioning at 717-383-4479.

Check Your Fuel Source

Try turning on another gas appliance. If it doesn’t work, your natural gas service could be turned off, or you could be out of propane.

Strine's Heating & Air Conditioning Can Help with Furnace Problems

Followed our troubleshooting guide but your furnace still won’t work?

Call us today at 717-383-4479 or use our online scheduler. We’ll come out and diagnose the problem.

*Required fields