Furnace Repair Checklist
1. Check the Thermostat
First, ensure your thermostat is instructing your heater to turn on.
- Swap out the batteries if the display is empty. If the digital monitor is scrambled, the thermostat might need to be swapped out.
- Ensure the switch is on “heat” as opposed to “off” or “cool.”
- Make certain the program is displaying the correct day and time and is programmed to “run.” If you’re having a hard time turning off the setting, adjust the temperature by utilizing the up/down arrows and pressing the “hold” button. This will cause the furnace to ignite if thermostat is causing trouble.
- Increase the temperature setting to 5 degrees above the room temperature.
If your heater hasn’t kicked on within a few minutes, make sure it has power by moving the fan switch from “auto” to “on.” If the fan doesn’t operate, your furnace might not have power.
If you use a smart thermostat—such as one designed 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, call us at 203-772-8319 for heating and cooling service.
2. Inspect Breakers and Switches
Next, check if your breaker and furnace switch are on.
- Locate your main electrical panel. If you have no idea where it is, look for a silver metal box in your basement, garage or closet.
- Ensure your hands and feet are dry prior to using the panel or breakers.
- Find the breaker marked “furnace” or “heat,” and double-check it’s reading “on.” If you find that the breaker tripped, it will be in the middle or “off” spot.
- With one hand, quickly switch the breaker to the “on” position. If the breaker immediately trips and pops back to “off,” don't try to reset it and call a professional from Giordanos Heating and Air Conditioning at 203-772-8319 immediately.
It doesn’t matter how old your furnace is or what brand it is, it has at minimum one standard wall switch placed on or close to it.
- Ensure the control is moved up in the “on” spot. If it was turned off, expect your furnace to take up to five minutes to start. (If you’re unaware of where your furnace is located, look in your basement, garage or utility closet. It may also be in a crawl space or attic.)
3. Replace the Air Filter
When we consider heating issues, a grungy, clogged air filter is frequently the top culprit.
If your filter is too dusty:
- Your heat won’t be able to stay on, or it might overheat from restricted airflow.
- Your heating costs could be higher because your furnace is switching on more often.
- Your heating system might fail sooner than it should since a dirty filter triggers it to work overtime.
- Your heater may be disconnected from power if an excessively clogged filter is the cause of a tripped breaker.
Based on what type of heater you own, your air filter can be found in the interior of the blower compartment of your furnace, an attached filter case or wall-mounted return air grille.
To put in a new filter:
- Switch off your heater.
- Remove the filter and tilt it toward the light. If you can’t view light through it, use a new one.
- Insert the new filter with the arrow pointing toward the heating system to prevent damage.
Flat filters should be replaced every month, while pleated filters should last about three months. If you have children or pets, you may have to put in a new filter more frequently.
To make the process go more quickly in the future, write with a permanent writing tool on your furnace outside or ductwork to indicate the airflow direction and filter size.
4. Examine the Condensate Pan
Also known as drain pans, condensate pans catch water your furnace pulls from the air.
If water is seeping from within your furnace or its pan has standing water in it, use these guidelines.
- If your pan contains a drain (look for a PVC pipe), double-check that it isn’t full. If it requires draining, drop in a special pan-cleaning tablet you can buy at home improvement or hardware retailers.
- If your pan contains a pump, check the float switch. If the button is jammed “up” with water in the pan, reach us at 203-772-8319, because you will probably need a new pump.
5. Check for Heating Error Codes
If failures keep on happening, peek inside your heater’s plastic window to confirm the blower motor’s status. Depending on the model, the light may also be mounted on the exterior of your furnace.
If you see anything except a steady, colored light or twinkling green light, contact us at 203-772-8319 for HVAC service. Your heater might be emitting an error code that is calling for expert assistance.
6. Brush off the Flame Sensor
If your furnace attempts to operate but switches off without putting out warm air, a dirty flame sensor could be to blame. When this happens, your heating system will try to start three times before a safety feature powers it down for about an hour.
If you feel confident with opening up your heater, brushing off your flame sensor is a job you are able to do yourself. Or, one of our heating service specialists can finish it for you.
If you are fine with cleaning the sensor yourself, you should have:
- A 1/4” hex screwdriver or wrench
- Piece of light grit sandpaper, steel wool or emery cloth
- An unused paper towel
- Disable the heater’s power through its wall switch or breaker. If you don’t have an electric gas valve, you have to shut off the gas as well.
- Remove the heating system’s front panel and follow the wire to the flame sensor.
- Take off 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.
- Put the sensor back in.
- Put the furnace doors back on.
- Turn the furnace’s power back on. It may run through a series of tests before resuming usual operation. If your heater doesn’t turn on, the sensor might need to be replaced or something else may be causing a problem. If this occurs, call us at 203-772-8319 for heating and cooling repair help.
7. Light the Pilot Light
If you own an aging heater, the pilot light could be turned off. To reignite it, look for the directions on a sticker on your furnace, or try these guidelines.
- Locate the switch beneath your furnace labeled “pilot,” “on” and “off.”
- Move the switch to the “off” position.
- Don’t do anything for at least five minutes to prevent creating a fire.
- Push the dial to “pilot.”
- Press the “reset” lever as you push the flame of a long lighter to the pilot light opening.
- Depress the “reset” switch once the pilot light is ignited.
If you have used the list twice and the pilot light still won’t burn or keep ignited, get in touch with us at 203-772-8319 for furnace service.
Check Your Fuel Supply
Try turning on a second gas appliance. If it doesn’t work, your natural gas service may be shut off, or you might have run out of propane.