When your furnace won’t start, doing your own furnace repair in Port Orchard, Washington, can feel pretty overwhelming.

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

There are a few speedy, inexpensive fixes you can do on your own 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 contacting an HVAC professional.

If you find you need help from a heating and cooling pro and live in Port Orchard, Air Masters Heating & Cooling can assist you. We can repair most makes of heating systems and also provide emergency furnace repair.

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

While you’re talking with us, consider an annual furnace maintenance plan that could help you avoid problems in the future. We can tell you how frequently your furnace should be inspected by one of our NATE-certified Pros.

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

Furnace Repair Checklist

1. Check the Thermostat

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

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” rather than “off” or “cool.”

Ensure the program is showing the appropriate 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 make the furnace to ignite if thermostat programming is causing a problem.

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 run, your furnace might not have power.

Smart Thermostat

If you have a smart thermostat—like one made by Nest, Ecobee, Lux, Honeywell or Bosch—troubleshooting is very model-specific. Refer to the manufacturer’s website for help. If you still can’t get your Wi-Fi thermostat to work, call us at 360-205-7115 for heating and cooling service.

2. 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 have no idea 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.

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,” leave it alone and contact a professional from Air Masters Heating & Cooling at 360-205-7115 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, it could take your furnace 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 problems, a filthy, clogged air filter is often to blame.

If your filter is too dirty:

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

Depending on what make of furnace you have, your air filter can be found 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 angle it toward the light. If you can’t see light through it, get a new one.
  3. Install 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 get a washable filter that will last about 10 years. If you have children or pets, you may have to change your filter sooner.

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

4. Inspect the Condensate Pan

Commonly known as drain pans, condensate pans hold 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 get at home improvement or hardware stores.
  • If your pan has a pump, check the float switch. If the switch is stuck “up” with standing water in the pan, contact us at 360-205-7115, because you will possibly need a new pump.

5. Check for Furnace Error Codes

If malfunctions persist, take a look inside your furnace’s plastic window to verify 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 else besides a steady, colored light or blinking green light, call us at 360-205-7115 for HVAC service. Your furnace may be giving an error code that is calling for professional service.

6. Clean the Flame Sensor

If your furnace tries to start but switches off without blowing heat, a dirty flame sensor could be to blame. When this occurs, your furnace will make an attempt to turn on three times before a safety feature shuts 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
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