Furnace Repair Checklist
1. Examine the Thermostat
To begin, make sure your thermostat is instructing your furnace to ignite.
Digital Thermostat
- Swap out the batteries if the monitor is blank. If the digital screen is scrambled, the thermostat may need to be swapped out.
- Make certain that the switch is on “heat” rather than “off” or “cool.”
- Make sure the program is displaying the right day and time and is set to “run.” If you’re having trouble overriding the schedule, adjust the temperature by using the up/down arrows and pressing the “hold” button. This will cause the furnace to turn on if thermostat is causing a problem.
- Increase the temperature setting to 5 degrees above the room temperature.
If your heat hasn’t started within a few minutes, make sure it has electricity by toggling the fan switch from “auto” to “on.” If the fan doesn’t operate, your furnace might not have power.
Smart Thermostat
If you use a smart thermostat—like one manufactured 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, contact us at 951-299-9853 for heating and cooling service.
2. Check Breakers and Switches
Next, verify your breaker and furnace switch are on.
- Find your main electrical panel. If you don’t know where it is, search for a silver metal box in your basement, garage or closet.
- Ensure your hands and feet aren’t moist in advance of using the panel or breakers.
- Look for the breaker marked “furnace” or “heat,” and make sure it’s switched “on.” If you find that the breaker tripped, it will be in the middle or “off” area.
- With one hand, firmly flip the breaker to the “on” position. If the breaker instantly trips and pops back to “off,” don't try to reset it and call a team member from Cool Air Solutions at 951-299-9853 immediately.
It doesn’t matter how old your furnace is or what brand it is, it has at minimum one ordinary wall switch placed on or by it.
- Ensure the switch is moved up in the “on” position. If it was switched off, expect your furnace to take up to five minutes to start. (If you’re unsure where to locate your furnace, check your basement, garage or utility closet. It may also be in a crawl space or attic.)
3. Get a New Air Filter
When we consider heating problems, a dirty, blocked air filter is regularly the top culprit.
If your filter is too dirty:
- Your heater won’t stay on, or it might overheat from limited airflow.
- Your energy costs might go up because your heat is working more often.
- Your heating system might stop working prematurely since a dusty filter forces it to work harder.
- Your heating system might lose power if an overly filthy filter causes the breaker to trip.
While it depends on what type of heating system you use, your air filter is located inside the blower compartment of your heating system, an attached filter case or wall-mounted return air grille.
To replace your filter:
- Cut the power to your heating system.
- Take out the filter and tilt it toward the light. If you can’t notice light through it, get a new one.
- Install the new filter with the arrow motioning toward the heater to keep damage from happening.
Flat filters ought to be replaced once a month, while pleated filters should last about three months. If you have children or pets, you could have to replace your filter sooner.
To make the procedure go more quickly down the road, use a permanent pen on your heating system housing or ductwork to list the airflow direction and filter size.
4. Inspect the Condensate Pan
Otherwise known as drain pans, condensate pans catch liquid your heating system draws from the air.
If water is leaking from within your heating system or its pan has too much water in it, use these recommendations.
- If your pan contains a drain (look for a PVC pipe), check that it’s clear. If it needs to be drained, get a special pan-cleaning tablet you can purchase at home improvement or hardware shops.
- If your pan uses a pump, take a look at the float switch. If the button can’t be moved from the “up” position with liquid in the pan, reach us at 951-299-9853, because you will likely have to install a new pump.
5. Watch for Heater Error Codes
If failures keep on happening, take a look inside your heater’s plastic window to check the blower motor’s status. Depending on the type, the light might also be fixed on the outside of your furnace.
If you notice anything other than a solid, colored light or blinking green light, reach us at 951-299-9853 for HVAC service. Your heating system could be communicating an error code that requires professional help.
6. Scrub the Flame Sensor
If your furnace makes an effort to start but switches off without distributing warm air, a grimy flame sensor could be to blame. When this takes place, your heater will try to ignite three times before a safety device powers it down for around an hour.
If you feel confident with removing the panels from your heater, brushing off your flame sensor is a task you can do yourself. Or, one of our heating service specialists can finish it for you.
If you are confident cleaning the sensor on your own, you should have:
- A 1/4” hex screwdriver or wrench
- Piece of light grit sandpaper, steel wool or emery cloth
- A dry, clean paper towel
As the next step:
- Shut off the heater’s power with its wall switch or breaker. If your gas valve isn’t electric, you have to switch off the gas as well.
- Take off the heater’s front panel and track the wire to the flame sensor.
- Take off the rod and use your sandpaper, steel wool or emery cloth to gently scrub the metal rod.
- Wipe off the rod with a paper towel.
- Remount the sensor.
- Secure the furnace doors.
- Restore power to the furnace. It may proceed through a series of tests before continuing normal operation. If your heating system doesn’t ignite, the sensor could require replacement or something else might be wrong. If this takes place, contact us at 951-299-9853 for heating and cooling repair help.
7. Reignite the Pilot Light
If you are using an older furnace, the pilot light could be extinguished. To relight it, look for the instructions on a sheet on your furnace, or use these steps.
- Look for the switch on the bottom of your heating system labeled “pilot,” “on” and “off.”
- Push the switch to the “off” position.
- Take a break for at least five minutes to avoid creating a fire.
- Push the knob to “pilot.”
- Press the “reset” button as you push the flame of a long lighter to the pilot light opening.
- Depress the “reset” lever once the pilot light is ignited.
If you have used the list twice and the pilot light still won’t ignite or remain ignited, get in touch with us at 951-299-9853 for furnace service.
Examine Your Energy Delivery System
Try switching on an additional gas appliance. If it doesn’t function, your natural gas source might be turned off, or you might have run out of propane.