Why Won’t My Furnace Turn On?

furnace not turning on

Jake Smith, Online Marketing Strategist
Technically Reviewed by Jake Smith, Online Marketing Strategist on Sep 15, 2023 | Written by Alpha Mechanical Editorial Contributors

Before the seasons change and the chilly air settles into the Sacramento air, it is vital to ensure that your heating system is working properly. What happens when you discover that the furnace won’t ignite or the thermostat won’t kick on furnace? Assuming you have had an annual HVAC tune-up in Sacramento, when a furnace is not turning on it is usually a simple fix in which no professional needs to step in. If you are unsure why your furnace is not kicking on, then it may be time to attempt to troubleshoot it. In this article we will delve into the possible causes for a faulty furnace as well as provide ways to troubleshoot the problem to avoid emergency heating repairs and a cold home.

Reason #1 Tripped Circuit Breaker

circuit breaker inspect

Without electricity, your furnace won’t kick on. The first thing you are going to want to check if your furnace won’t turn on is your circuit breaker. It is possible that your breaker tripped and now the furnace switch is off.

Troubleshooting Tip: Check your Circuit Breaker

Locate your circuit breaker panel and be sure that all the switches for your HVAC system are set to “ON”. If you find that they are not in the “ON” position, carefully snap the breakers back into place to restore power to your furnace. Be sure to close the furnace door in order that the safety switch can activate the furnace correctly. Once you have completed this step and your furnace won’t start despite the breaker being in the proper position, it’s time to move onto other furnace repair issues.

Reason #2 Restricted Airflow

air filter

It can be frustrating to come home to or wake up in a cold house on a winter day. You may be wondering why won’t my heater turn on? A clogged or dirty air filter can be another one of those common furnace problems that is oftentimes forgotten. This job doesn’t need to be left to the HVAC experts because it is as simple as swapping it out for a new one. When airflow circulation is cut off, it prevents the HVAC system from turning on and working appropriately at any setting. Furnace’s come with a safety feature that prevents it from turning on in such circumstances. You may also want to check that your ducts and vents are not being blocked or clogged with debris as well. If you suspect that the issue is something more serious there are other options for heating repair in Sacramento.

Troubleshooting Tip: Replace Air Filter

If your heating system is not turning on, turn it off entirely for this step. Turn your heating system off entirely before tampering with your HVAC air filter. Remove the filter and hold it up to the light: if light does not pass through the fibers, you may want to consider replacing it. Double check the correct size of the filter located on the side of the filter when ordering or purchasing a new one. When installing a new filter, align it with the direction of the airflow coming from the furnace. If you are still unsure how to accurately change out the air filter, your HVAC experts in Sacramento are one phone call away for guidance. Furthermore, if your air ducts need to be cleaned, it is critical to schedule a heating system tune-up

Reason #3 Thermostat is Faulty


Sometimes when your furnace doesn’t fire up, it might not have to do with your furnace at all. Your thermostat is the mainline of communication for your HVAC system and when it is not operating properly, your furnace won’t turn on when you set it to do so. When any thermostat wires are loose, broken or dusty, your thermostat cannot properly regulate the furnace’s heat. If you recently experienced a power outage, your thermostat may have reset itself, or maybe your home has an energy efficient programmable thermostat that is operating on a set schedule that you placed for it when it was first installed. If your furnace is not turning on automatically, it might be because of a schedule you have it set on. There are a few things you can do to troubleshoot when the furnace is not turning on with thermostat settings.

Troubleshooting Tip: Reset/Double Check Thermostat

First step is to check that it is set to “HEAT” as well as “AUTO” rather than “FAN”. If your thermostat cannot detect whether the room has reached the desired temperature, it will not turn on. Next step would be to make sure that none of the wires are blocked or damaged. You can check this by unscrewing your thermostat to see if the wires are securely attached and there is no visible dust surrounding the wires. Similar to other household appliances, the thermostat might need a battery change as well. If your furnace is not heating your house consistently and you have not placed special settings on your programmable thermostat, switching to AA lithium batteries instead of alkaline batteries can extend the life of your system. Check the display for any error codes. If after you have completed these steps your thermostat won’t kick on furnace, your furnace is not working for another reason and we should check a few more things.

Reason #4 Indoor Fan Motor

blower motor

When your gas furnace is not turning on, there may be a dirty blower motor that needs cleaning before it can run correctly. Without a functioning blower motor, your furnace will be unusable. The purpose of the blower motor is to pull the air from inside your home, move it through your furnace, over the heat exchanger and back into your duct system as the warm and comforting air you need to heat your home once more. Your furnace won’t light or operate if there is no airflow. The heat exchanger can begin to overheat if it is not being exposed to enough moving air and the heating process will discontinue, powering off your system.

Troubleshooting Tip: Clean out your Blower Motor

Using a shop-vac and its attachments to really ensure that you clean out the area of any dust and debris is an efficient way to improve the fan performance.

Reason #5 Burner Ignition Faulty

pilot/ ignition

If your furnace won’t turn on but fan works, it could be that the pilot light (or ignition switch) is out. A nifty safety feature that your furnace has that you may be unaware of is your pilot light which prevents pumping natural gas or propane into your home. When the heat exchanger does not sense an ignition, it will not power on the furnace. This means that if there is dirt or grime inhibiting the sensor’s abilities, that could be the difference between a chilly or toasty night in your home. Pilot light fixes and cleans should be left to the professionals; this is not on the list of DIY heating repairs. A trusted HVAC company in Fair Oaks or your surrounding area will offer heating solutions with a furnace flame sensor replacement and the cleaning it needs to get up and running again.

Troubleshooting Tip: Check the Pilot Light

If the furnace pilot light won’t stay lit, sometimes the furnace just needs a reset. Start by turning the furnace off and inspect for any damage. Call your local Sacramento area HVAC company for affordable furnace maintenance if you believe that your pilot light has gone out altogether. When the furnace won’t ignite but you hear a clicking noise, it is highly likely that your ignition sensor is the culprit. First thing to do is turn off the gas in the furnace. If the electric furnace is not turning on, power down the electricity to the furnace for a rest. Remove the front panel to find the ignitor located usually near the burners. If the sensor is dirty, remove it with a screwdriver and clean it without breaking it. Once it is cleaned, restore it to the exact location that you found it. Put the front panel back on, turn the gas back on and attempt to start the furnace up again.

Reason #6 Natural Gas Supply Issues

low energy supply

In the California region, it is becoming less and less popular for homes today to still carry natural gas furnaces especially with the SMUD HVAC rebates available today for switching to heat pump systems. Regardless if your HVAC heater is not turning on and you do have an oil supply or any kind, it is important to check it off your list of reasons you could be experiencing furnace issues.

Troubleshooting Tip: Contact gas/propane company

Lack of fuel could impede upon your furnace’s ability to turn on. The best way to check your fuel supply is by trying another gas appliance in your home, such as your stove. If your stove is also not being given a gas supply, contact your propane company because you just identified your issue. If your furnace gas valve is not opening, there are troubleshooting steps to take for that issue as well otherwise contact a local HVAC company for guidance.

Alpha Mechanical can help you with  Heat Pump Repair in Sacramento?

Signs That You Need To Repair Your Furnace

There are a few common reasons why a furnace is not turning on which we have covered above, however, there may be some other signs before, during or after the fact that act as warnings to you that something is off:

  • Your furnace is expelling unpleasant smells
  • Your furnace has a water or gas leak
  • Furnace pressure switch failure
  • You can’t turn on your furnace system
  • Feeling light headed or dizzy (possible carbon monoxide poisoning)
  • There has been a spike in your utility bills and energy consumption
  • Your thermostat is being unresponsive

More Learning Resources!

Put Comfort First: Contact Furnace Repair Professionals in Sacramento

Now that you have completed the 6 troubleshooting steps to determine why furnace won’t turn on, it is time to put it in the hands of a professional HVAC technician. A professional can offer you heating system diagnostics and address the root cause of the malfunction. Scheduling routine maintenance with an HVAC company before the next winter season will provide your heating system lifespan to exceed your expectations. Alpha Mechanical and our company’s technicians are here when your furnace won’t turn on in Sacramento. Whether you are within our service area or not, our website offers a variety of furnace tips and tricks to troubleshoot your HVAC heating system.

Frequently Asked Questions

Is it advisable to attempt DIY repairs for heating problems, or should I immediately seek professional help?

There are several troubleshooting steps you can take in order to attempt to resolve the issue before contacting a professional including changing your air filter, checking your circuit breaker and cleaning your systems blower motor.

What are the key indicators that my heating system requires urgent repair assistance?

When there is a visible leak or a strange odor coming from your unit, it is critical to call in for help right away. Furthermore, if you reach a point in your troubleshooting where something breaks or you witness any damage that has happened behind your control panel, you should call a technician out for a proper inspection/possible furnace replacement in Sacramento.

What should I do if my thermostat isn't responding to adjustments?

Check that the batteries don’t need to be replaced and that there are no wiring or dirt issues hindering it from responding correctly. Secondly, your thermostat may give you an indication that your unit is not working as a whole and may need a reset. Programmable thermostats provide a code that can lead you to the cause of the issue.

Common Cooling
and Heating Issues!
See If We Service
Your Neighborhood!
We Protect Your Investment.
100% Piece of Mind Coverage.
Use Our Exclusive Online Discounts!

Learning Resources

Take the Next Step

Contact Us Today

    we strive to put all our energy so that you save yours!

    we strive to put all our energy so that you save yours!

    Mon to Fri: 8am to 5pm
    Sat & Sun: Closed
    Call or Text
    (916) 848-5980
    10418 Fair Oaks Blvd
    Fair Oaks, CA 95628
    Mon to Fri: 8am to 5pm
    Sat & Sun: Closed
    Call or Text
    (916) 848-5980
    10418 Fair Oaks Blvd
    Fair Oaks, CA 95628
    Email Us
    Email Us
    Google Review Link
    Copyright © 2024 Alpha Mechanical Systems, Inc. All Rights Reserved.  |  Privacy Policy  |  Terms & Conditions  |  Contact Us
    Call Now Button