furnace repair

Pacheco 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 couple of time-saving, 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 an expert and live in Pacheco, Clean Air HVAC can assist you. We work on most makes of heating systems.

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

While you’re talking with us, think about a routine furnace maintenance plan from Clean Air HVAC that could help you avoid problems in the future. We can tell you how regularly your furnace should be examined by one of our NATE-certified specialists.

Go through our easy guide below to start troubleshooting your furnace. Most of these steps don’t require mechanical know-how.

Steps for Furnace Troubleshooting

Check the Thermostat

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

If you have a 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 set to the right 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 make the furnace to turn on if thermostat programming is causing an issue.
  • Increase the temperature setting to 5 degrees warmer than the room temperature.
Digital Thermostat

If your furnace hasn’t turned on within few minutes, make sure it has power by toggling the fan switch from “auto” to “on.” If the fan doesn’t run, 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. Refer to 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.

  • Locate 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.
  • Locate 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 get in touch with a professional from Clean Air HVAC at 925-233-6238 right away.

No matter 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, it could take your furnace 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 problems, a filthy, clogged air filter is frequently the top offender.

If your filter is too dirty:

  • Your furnace won’t keep heating your home, or it could overheat from restricted airflow.
  • Your energy bills could increase because your furnace is turning on more often.
  • Your furnace could fail prematurely because a dirty filter causes it to work harder.
  • Your furnace can lose power if an overly dirty filter causes the breaker to trip.

Depending on what make 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.

Replacing a furnace filter

To replace your filter:

  • Turn off your furnace.
  • Remove the filter and tilt it toward the light. If you can’t see light through it, use a new one.
  • Put in the new filter with the arrow pointing toward the furnace to avoid damage.

Flat filters should be replaced monthly, 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 replace your filter more frequently.

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

Examine the Condensate Pan

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

If water is seeping 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 isn’t full. If it needs to be drained, use a special pan-cleaning tablet you can purchase at home improvement or hardware stores.
  • If your pan uses a pump, check the float switch. If the switch is stuck “up” with standing water in the pan, contact Clean Air HVAC at 925-233-6238, because you will possibly need a new pump.

Peek Inside Your Furnace

If malfunctions continue, 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 Clean Air HVAC at 925-233-6238. Your furnace may be giving an error code that is calling for professional service.

Clean the Flame Sensor

If your furnace tries to start but turns off without distributing heat, a dirty flame sensor could be to blame. When this occurs, your furnace will make an attempt to start three times before a safety feature turns it off 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 experts at Clean Air HVAC 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:

  • Disable 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.
  • Lift off 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 carefully 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 proceed through a sequence of checks before proceeding with usual operation. If your furnace doesn’t turn on, the sensor may need to be replaced or something else might be wrong. If this happens, call Clean Air HVAC at 925-233-6238 for assistance.

Relight the Pilot Light

If you own 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.

  • 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 sparking 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, get in touch with Clean Air HVAC at 925-233-6238.

Check Your Fuel Source

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

Clean Air HVAC Can Help with Furnace Problems

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

Call us today at 925-233-6238 or use our online scheduler. We’ll come out and pinpoint the problem.

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