When your furnace won’t start, doing your own furnace repair in York, Pennsylvania, can feel overwhelming.

Figuring out a furnace-related problem might feel like a challenging task when your heat won’t turn on. But it doesn’t have to be like that.

There are a couple of fast, reasonable fixes you can do by yourself to skip 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 getting in touch with an HVAC professional.

If you find you need help from a heating and cooling expert and live in York, Strine's can provide assistance to you. We can repair most types of heating systems and also provide emergency furnace repair.

If it’s time for a new heating system, we also do furnace installation.

While you’re chatting with us, think over a routine furnace maintenance plan that might help you avoid repairs in the future. We can tell you how frequently your furnace should be inspected by one of our NATE-certified professionals.

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

Furnace Repair Checklist

1. Check the Thermostat

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

Digital Thermostat

Replace 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” as opposed to “off” or “cool.”

Ensure the program is displaying the correct day and time and is set to “run.” If you’re having a hard time 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 an issue.

Increase the temperature setting to 5 degrees warmer than the room temperature.

If your furnace hasn’t kicked on within a couple minutes, make sure it has power by toggling the fan switch from “auto” to “on.” If the fan doesn’t begin to run, your furnace could be without power.

Smart Thermostat

If you have a smart thermostat—like one made by Nest, Ecobee, Lux, Honeywell or Bosch—troubleshooting is very model-specific. Check the manufacturer’s website for help. If you still can’t get your Wi-Fi thermostat to work, call us at 717-383-4479 for heating and cooling service.

2. Examine Breakers and Switches

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

Find your house’s main electrical panel. If you don’t know where it is, search 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.

Find 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,” leave it alone and contact a professional from Strine's at 717-383-4479 right away.

It doesn’t matter how old your furnace is or what brand it is, it has at least one standard wall switch located on or near it.

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

3. Replace the Air Filter

When it comes to furnace breakdown, a filthy, clogged air filter is regularly the top offender.

If your filter is too dirty:

  • Your furnace won’t be able to stay on, or it could overheat from limited airflow.
  • Your energy bills could go up because your furnace is turning on more often.
  • Your furnace could stop working too soon because a dirty filter causes it to work harder.
  • Your furnace can be disconnected from power if an extremely dirty filter causes the breaker to trip.

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

To replace your filter:

  1. Turn off your furnace.
  2. Take out the filter and tilt it toward the light. If you can’t see light through it, get a new one.
  3. Insert the new filter with the arrow pointing toward the furnace to avoid damage.

Flat filters should be replaced once a 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 change your filter more frequently.

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

4. Inspect the Condensate Pan

Commonly known as drain pans, condensate pans catch water your furnace draws 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 purchase at home improvement or hardware stores.
  • If your pan contains a pump, take a look at the float switch. If the switch is stuck “up” with standing water in the pan, contact us at 717-383-4479, because you will likely need a new pump.

5. Check for Furnace Error Codes

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

If you see anything else besides a steady, colored light or blinking green light, call us at 717-383-4479 for HVAC service. Your furnace may be giving an error code that needs professional service.

6. 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 try to turn on 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 on your own. Or, one of our heating service experts 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:

  • Turn 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 track 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 could run through a sequence of checks before proceeding with normal operation. If your furnace doesn’t turn on, the sensor may need to be replaced or something else might be wrong. If this happens, contact us at 717-383-4479 for heating and cooling repair assistance.

7. Relight the Pilot Light

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

  • Find 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.”
  • Hold down 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 us at 717-383-4479 for furnace service.

Check Your Fuel Source

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

We Can Help with HVAC Repair

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

Call us today at 717-383-4479 or contact us online. We’ll come out and figure out the problem.

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