Furnace Repair Checklist
1. Check the Thermostat
First, ensure your thermostat is telling your heat to start.
- Swap out the batteries if the screen is not displaying anything. If the digital display is messed up, the thermostat could need to be replaced.
- Ensure the switch is switched to “heat” instead of “off” or “cool.”
- Ensure the program is displaying the correct day and time and is programmed to “run.” If you’re having trouble overriding the schedule, adjust the temperature by utilizing the up/down arrows and using the “hold” button. This will cause the furnace to turn on if thermostat is causing trouble.
- Set the temperature setting to 5 degrees warmer than the room temperature.
If your furnace hasn’t turned on within a couple minutes, make certain that it has electricity by toggling the fan switch from “auto” to “on.” If the fan doesn’t operate, your heating system could be without power.
If you have a smart thermostat—for example one made by Nest, Ecobee, Lux, Honeywell or Bosch—troubleshooting is very model-specific. Check the manufacturer’s website for help. If you aren’t able to get your Wi-Fi thermostat to function, reach us at 804-302-6657 for heating and cooling service.
2. Examine Breakers and Switches
Next, verify your breaker and furnace switch are on.
- Find your main electrical panel. If you have no idea where it is, keep an eye out for a metallic metal box in your basement, garage or closet.
- Ensure your hands and feet aren’t wet in advance of touching the panel or breakers.
- Look for the breaker titled “furnace” or “heat,” and ensure it’s turned “on.” If you find that the breaker tripped, it will be in the middle or “off” spot.
- Moving one hand, firmly turn the breaker to the “on” position. If the breaker instantly trips and pops back to “off,” don't try to reset it and contact a team member from Herman Allen Plumbing, Heating & Cooling at 804-302-6657 right away.
Regardless of your furnace’s age or brand, it has at minimum one regular wall switch installed on or close to it.
- Ensure the switch is facing up in the “on” spot. If it was turned off, it could take your furnace up to five minutes to ignite. (If you don’t know where your furnace is located, look in your basement, garage or utility closet. It could also be in a crawl space or attic.)
3. Get a New Air Filter
When we think about heater issues, a filthy, blocked air filter is frequently the top culprit.
If your filter is too dusty:
- Your heater won’t be able to stay on, or it may overheat from limited airflow.
- Your heating bills might be higher because your furnace is turning on more often.
- Your heat might break down too soon since a dirty filter causes it to work overtime.
- Your furnace can be cut off from power if an overly filthy filter is the cause of a tripped breaker.
Depending on what make of heating system you have, your air filter can be found in the interior of the blower compartment of your heater, an attached filter case or wall-mounted return air grille.
To swap out your filter:
- Switch off your furnace.
- Take out the filter and angle it toward the light. If you can’t view light through it, replace it.
- Install the new filter with the arrow pointing toward the heating system to keep damage from happening.
Flat filters ought to be replaced monthly, 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 easier down the line, draw with a permanent marker on your heating system outside or ductwork to indicate the airflow direction and filter size.
4. Look at the Condensate Pan
Commonly known as drain pans, condensate pans capture water your heater removes from the air.
If water is seeping from within your furnace or its pan has too much water in it, follow these guidelines.
- If your pan contains a drain (look for a PVC pipe), double-check that it isn’t full. If it requires draining, use a special pan-cleaning tablet you can buy at home improvement or hardware retailers.
- If your pan has a pump, inspect the float switch. If the button can’t be moved from the “up” position with standing water in the pan, contact us at 804-302-6657, because you will probably need a new pump.
5. Look for Heating Error Codes
If malfunctions continue, take a look at your heating system’s plastic window to confirm the blower motor’s status. Subject to the type, the light could also be attached on the surface of your furnace.
If you see anything except an uninterrupted, colored light or flickering green light, call us at 804-302-6657 for HVAC service. Your heating system could be emitting an error code that needs specialized service.
6. Clean the Flame Sensor
If your furnace makes an effort to run but turns off without distributing heat, a grimy flame sensor can be to blame. When this occurs, your furnace will try to turn on three times before a safety device turns it off for about an hour.
If you feel confident with removing the panels from your furnace, gently scrubbing your flame sensor is work you are able to do yourself. Or, one of our heating service professionals can finish it for you.
If you are confident cleaning the sensor yourself, you require:
- A 1/4” hex screwdriver or wrench
- Section of light grit sandpaper, steel wool or emery cloth
- A fresh paper towel
As the next step:
- Disable the heating system’s power with its wall switch or breaker. If your gas valve isn’t electric, you will need to switch off the gas along with it.
- Lift off the furnace’s front panel and follow the wire to the flame sensor.
- Remove the rod and use your sandpaper, steel wool or emery cloth to gently clean the metal rod.
- Clear the rod with a paper towel.
- Put the sensor back in.
- Secure the furnace doors.
- Restore power to the furnace. It could go through a sequence of inspections before continuing usual operation. If your furnace doesn’t ignite, the sensor might require replacement or something else may be wrong. If this happens, call us at 804-302-6657 for heating and cooling repair help.
7. Relight the Pilot Light
If you are using an outdated furnace, the pilot light could be turned off. To reignite it, locate the instructions on a label on your furnace, or use these guidelines.
- Locate the lever beneath your heater that says “pilot,” “on” and “off.”
- Push the switch to the “off” position.
- Don’t do anything for at least five minutes to prevent sparking a fire.
- Turn the switch to “pilot.”
- Press the “reset” button as you bring the flame of a long lighter to the pilot light opening.
- Release the “reset” switch once the pilot light is ignited.
If you have gone through the guide twice and the pilot light still won’t ignite or stay lit, call us at 804-302-6657 for furnace service.
Double-Check Your Energy Delivery System
Try switching on a second gas appliance. If it doesn’t work, your natural gas source might be shut off, or you could be out of propane.