The best way to keep your furnace running at peak performance and safety is by scheduling annual furnace maintenance every fall. This will improve your furnace’s life expectancy, reduce the need for repairs, and make your home a lot safer and more efficient. And we haven’t even mentioned the fact that most (if not all) HVAC warranties will be voided if you neglect annual professional tune-ups.

Unfortunately, sometimes heating emergencies do arise, and often at the worst time, like when you’re preparing for guests. Luckily, if you run into a problem with your furnace, you can try these furnace troubleshooting tips before calling the pros.

How to Restore Heat: 7 Things to Check Before Calling the Pros

Check Power

In addition to checking your electrical panel to make sure your system is receiving power, you’ll also want to double-check that all the electrical switches are on for your heating system:

Emergency Off Switch – the emergency on/off switch is normally located outside of the basement or heating system area so that someone can turn off power to the heating system without having to enter a potentially dangerous area. Make sure this switch is turned on.

Second Off Switch – the second on/off switch is located near the indoor heating equipment itself. Make sure the power switch near your heating equipment is in the “on” position. 

Breaker Panel/Fuse Box – as mentioned before, you want to make sure the heating system is receiving power at the building electrical panel, which could be either a breaker or fuse box. Learn how to safely reset a breaker or replace a blown fuse.

If your electrical panel continues to blow, do not restore power to the circuit. Instead, contact a professional right away. It’s important to know the underlying cause of your tripping breaker or blown fuse situation.

Check Thermostat

It may sound obvious, but make sure your thermostat is set to “heat” and fan is set to “auto.”
Set the thermostat to at least 5 degrees higher than the room temperature.
Replace the batteries.
If you have an electromechanical, non-programmable thermostat, you may need to remove the cover and lightly dust the inside. To get in between the metal coils and contact plates, try using a soft piece of paper (a dollar bill can work as well). Be very delicate when dusting the inside of the thermostat.

If you are having any problems with your thermostat in the Birmingham, AL area, contact OnTime Service.

Check Furnace Filter

Anyone who knows anything about HVAC systems knows how important it is to maintain clean air filters. Some HVAC systems will even shut down if they detect a dirty and cogged air filter. This is because clogged air filters can inhibit airflow to the point of causing damage to your heating and cooling system.

So, if your furnace isn’t turning on or you are having airflow problems, the air filter is probably the first thing you should check.

  • Turn the furnace off using the on/off switch near your furnace. Make sure the thermostat is set to off.
  • When replacing your air filter, make sure the arrows are pointing in the direction of the airflow.
  • We recommend writing the date of replacement on the air filter tself so you know exactly how long it has been since the last filter replacement.
  • Set phone and calendar reminders to check the air filter every 30 days. Depending on your home and air filter, you will want to replace the filter every 30-90 days.
  • Hold up your air filter to the light to see if light can pass through the filter. If it looks dirty and clogged, it is. Replace it.
  • Keep several filters on hand for quick and easy replacements.
  • We recommend getting air filters with a minimum efficiency reporting value (MERV) rating of 7.
  • Check Access Panels/Doors

If you have any loose access panel doors, your furnace may not turn on as a safety precaution. Make sure your blower panel, air filter door, and any other access points are closed properly.

  • Make sure the thermostat is “off” and flip the furnace switch to “off.”
  • Then, securely close all access panels.
  • Keep in mind that you may need to screw them in.
  • Finally, try turning your furnace back on.

Check Vents and Registers

It’s important to keep all your vents and registers open for proper operation and airflow.

Look for your home’s events and registers.
Make sure they are unobstructed by furniture, drapes, boxes, and other stuff.
While most vents and registers come with a little lever to open/close them, always keep them fully open.

It’s a myth that you can save money and energy by closing off vents in unused rooms. Your HVAC system will use the same amount of power as always and all you will do is create excess pressure in your ductwork and HVAC system leading to more duct leaks and other problems.

If you have indoor air quality problems and ductwork inefficiencies, contact OnTime Service for professional duct cleaning and sealing solutions.

Check Furnace Flame

We wrote an extensive post on the importance of proper furnace flame pilot light color (spoiler: it’s blue).

While you should never attempt to fix the furnace flame color on your own, you can relight a pilot light on your own. Just make sure to clearly follow the direction in your owner’s manual and make sure that there is no built up gas around the system before you attempt to relight the pilot.

Learn more about the dangers of DIY furnace repair. When in doubt, contact the professionals at OnTime Service, located in Hoover, AL.

Check Gas Valve

If your pilot light is out and you are not able to relight it, someone may have accidentally closed off the gas valve or forgot to turn it back on.

  • To turn on your furnace’s gas valve, make sure the handle is parallel with the gas pipe.
  • To turn your gas valve off, turn the handle so it is perpendicular to the pipe.

Furnace Troubleshooting Recap:

  • Check all power switches and any tripped breakers or blown fuses.
  • Make sure you have a clean air filter (make sure arrow is pointing in direction of airflow).
  • Properly mount and close all access panels/doors.
  • Thermostat should be set to “heat” and fan should be set to “auto.”
  • Turn the thermostat up to at least 5 degrees higher than the room temperature.
  • Unblock and fully open all vents and registers.
  • Check gas valve and make sure it is on (parallel to pipe).
  • Relight pilot light (call a professional if furnace flame is flickering or any other color than blue).
  • When all else fails or you encounter a dangerous situation, contact a professional.

Don’t forget to test smoke and carbon monoxide detectors every 30 days. Make sure there is one of each protection device on each level of the home and outside of every sleeping area.

When to Call a Professional HVAC Technician

Your furnace involves many complicated and potentially dangerous components, such as the heat exchanger, gas lines and burners, and ventilation systems. Learn about the dangers of DIY furnace repair. And always contact a professional if you cannot get your furnace working properly by using the troubleshooting tips above.

When it comes to HVAC, proactive care is much cheaper and more effective than reactive care. Contact a trained HVAC technician from OnTime Service to correct the problem quickly on your schedule, with no mess.

If your furnace is working fine but seems to be on all the time, learn how to save money and reduce the demand on your furnace with these winter energy-saving tips.

As the winter season takes its toll on your furnace, it may be time to consider furnace replacement options. If it’s not quite time yet, learn how to extend the lifespan of your furnace.

Whether you need electrical, plumbing, or HVAC work done on your home, OnTime Service is committed to efficient and effective service with a 100% Satisfaction Guarantee.


Give OnTime Service a call to schedule your next electrical, plumbing, and HVAC appointment: (205) 872-1944

Our experience team of technicians is fully trained to handle any system. We will troubleshoot your home and give you straightforward pricing options.

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