Furnace Repair in Mount Pleasant, SC

HVAC man working on a furnace

When your heater won’t start, doing your own furnace repair in Mount Pleasant, SC, can feel overwhelming.

There are several quick, low-cost fixes you can take on yourself to avoid a heating repair call.

If your furnace refuses to turn on, won’t run consistently or won’t light, try the troubleshooting list below before calling an HVAC professional.

If you discover you need assistance from a heating and cooling expert and live in Mount Pleasant, Olde Towne Heating & Air can help you. We can repair most makes of furnaces.

CALL NOW 843-485-0967

If you’re ready for a new furnace, we also provide furnace installation.

While you’re talking with our team, consider a routine furnace maintenance plan from Olde Towne Heating & Air that could help you avoid breakdowns down the road. We can let you know how regularly your furnace should be inspected by one of our NATE-Certified professionals.

Use our simple list below to get to work on troubleshooting your HVAC system. Most of these processes don’t have the requirement of mechanical abilities to complete your furnace repair.

Furnace Repair Checklist

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1. Check the Thermostat

To begin, make certain that your thermostat is telling your heat to turn on.

Digital Thermostat

  • Replace the batteries if the screen is not displaying anything. If the digital monitor is mixed up, the thermostat may need to be changed.
  • Make certain that the button is switched to “heat” rather than “off” or “cool.”
  • Ensure the program is showing the right day and time and is scheduled to “run.” If you’re having problems turning off the setting, regulate the temperature with the up/down arrows and holding the “hold” button. This will cause the furnace to turn on if thermostat is causing an issue.
  • Turn the temperature setting to 5 degrees hotter than the room temperature.

If your heat hasn’t turned on within several minutes, make certain that it has power by changing the fan switch from “auto” to “on.” If the fan doesn’t start, your furnace might not have power.

Smart Thermostat

If you use a smart thermostat—for example one made by Nest, Ecobee, Lux, Honeywell or Bosch—troubleshooting will depend on your model. Take a look at the manufacturer’s website for support. If you still can’t get your Wi-Fi thermostat to function, call us at 843-485-0967 for heating and cooling service.

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2. Inspect Breakers and Switches

Next, check if your breaker and furnace switch are on.

  • Look for your main electrical panel. If you aren’t sure where it is, keep an eye out for a gray metal box in your basement, garage or closet.
  • Make certain that your hands and feet aren’t wet in advance of touching the panel or breakers.
  • Look for the breaker marked “furnace” or “heat,” and double-check it’s turned “on.” If you discover a tripped breaker, it will be in the middle or “off” spot.
  • Using one hand, firmly flip the breaker to the “on” position. If the breaker trips right away and pops back to “off,” don't try to reset it and call a professional from Olde Towne Heating & Air at 843-485-0967 immediately.

No matter your furnace’s age or brand, it has at least one ordinary wall switch installed on or close to it.

  • Ensure the control is moved up in the “on” spot. If it was shut off, anticipate your furnace could take up to five minutes to turn on. (If you’re unsure where to locate your furnace, look in your basement, garage or utility closet. It could also be in a crawl space or attic.)
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3. Replace the Air Filter

When it comes to furnace issues, a dirty, blocked air filter is often the top offender.

If your filter is too dirty:

  • Your heater won’t keep heating your home, or it could overheat from restricted airflow.
  • Your gas expenses could increase because your heater is switching on more than it should.
  • Your heat could fail sooner than it should due to the fact a dusty filter forces it to work overtime.
  • Your furnace can be cut off from power if an overly filthy filter causes the breaker to trip.

Depending on what make of furnace you own, your air filter will be within the blower compartment of your furnace, an attached filter case or wall-mounted return air grille.

To replace your filter:

  • Cut the power to your heater.
  • Pull out the filter and tilt it toward the light. If you can’t see light through it, use a new one.
  • Insert the new filter with the arrow facing toward the heating system to keep damage from happening.

Flat filters should be replaced once a month, while pleated filters should last about three months. If you have children or pets, you may have to replace your filter more frequently.

To make the process smoother down the line, use a permanent writing tool on your furnace outside or ductwork to list the airflow direction and filter size.

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4. Inspect the Condensate Pan

Also known as drain pans, condensate pans hold liquid your heating system pulls from the air.

If moisture is seeping from within your heating system or its pan has standing water in it, try these guidelines.

  • If your pan has 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 shops.
  • If your pan uses a pump, take a look at the float switch. If the switch is jammed “up” with water in the pan, reach us at 843-485-0967, because you will probably have to install a new pump.
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5. Watch for Heating Error Codes

If failures keep on happening, take a look within your heating system’s plastic window to confirm the blower motor’s status. Depending on the brand, the light may also be mounted on the outside of your furnace.

If you see anything other than a steady, colored light or blinking green light, reach us at 843-485-0967 for HVAC service. Your heater could be communicating an error code that requires specialized assistance.

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6. Clean the Flame Sensor

If your heating system makes an effort to start but shuts off without distributing warm air, a filthy flame sensor might be at fault. When this takes place, your heating system will attempt to ignite three times before a safety device turns it off for approximately an hour.

If you feel confident with removing the panels from your heater, brushing off your flame sensor is work you can do personally. Or, one of our heating service experts has the ability to do it for you.

If you want to clean the sensor yourself, you need:

  • A 1/4” hex screwdriver or wrench
  • Portion of light grit sandpaper, steel wool or emery cloth
  • A dry, clean paper towel


  • Turn off the furnace’s power by using its wall switch or breaker. If your gas valve isn’t electric, you have to shut off the gas along with it.
  • Remove the heating system’s front panel and trace the wire to the flame sensor.
  • Unscrew the rod and use your sandpaper, steel wool or emery cloth to gently scrub the metal rod.
  • Clear the rod with a paper towel.
  • Put the sensor back in.
  • Secure the furnace doors.
  • Switch the furnace’s power back on. It might go through a series of inspections before proceeding with regular running. If your heating system doesn’t start, the sensor might need to be replaced or something else could be creating an issue. If this occurs, get in touch with us at 843-485-0967 for heating and cooling repair assistance.
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7. Relight the Pilot Light

If you own an aging heating system, the pilot light could be extinguished. To light it, find the guide on a sheet on your furnace, or use these steps.

  • Find the switch beneath your heating system that says “pilot,” “on” and “off.”
  • Push the switch to the “off” position.
  • Don’t do anything for at least five minutes to limit the possibility for sparking a fire.
  • Push 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” button once the pilot light is lit.
  • If you have tried the instructions twice and the pilot light still won’t light or keep burning, call us at 843-485-0967 for furnace service.

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Examine Your Energy Delivery System

Try using an additional gas appliance. If it doesn’t function, your natural gas service could be shut off, or you may have run out of propane.

We Can Provide Furnace Servicing

Went through our troubleshooting list but your heater still refuses to heat?

Reach us right away at 843-485-0967 or contact us online. We’ll come to your house and pinpoint the problem.


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