In Phoenix, Arizona, heating systems aren’t nearly as important or coveted as much as high performing air conditioners. Even when a furnace goes out, it doesn’t exactly devastate a homeowner’s quality of life. At the same time, it can be quite the inconvenience for those unprepared. While repair or replacement costs can be a bummer, safety should also be a concern when a furnace isn’t turning on or getting gas.
At the end of the day, a heater with electrical or gas issues should never be taken lightly – even if you think the furnace is “only being stubborn” and not turning back on. Truth be told, you could be one split second away from life changing consequences. Although devastation isn’t common, it does occur – and usually comes as a surprise.
Seriously, Why Isn’t My Furnace Working?
Despite the ease of labeling your heating system obstinate, it’s important you understand the potential possibilities. The reality is, when a furnace isn’t turning on or getting gas, there’s a mechanical problem somewhere. Even though it may never reach freezing temperatures outside, this is not something you’ll want to ignore.
Nonetheless, if you’re switching on your heat for the very first time this season, it might take some time for ignition to occur. This depends on the time it takes for gas to reach the pilot. Those of you that barely use your furnace will probably experience this at some point. Try not to overthink the problem and never let your gas run too long. With that being said, here are 11 potential reasons why your furnace isn’t working properly.

1. Emergency Shut Off Switch Is Off.
In many situations, a malfunctioning furnace is a simple fix. When the emergency shut off switch is not in the “on” position, the heating system will not receive any gas. In turn, it may appear that it is not working properly. Whether the switch was accidentally bumped into or a curious child wanted to see what it did, a simple flip will solve the problem.
Most homeowners can find emergency switches outside of the basement (to protect them with access in case of a fire). In Arizona, they’re normally positioned on the furnace itself, near the electrical panel or in the garage.
2. The Pilot Light Is Out.
Despite newer models moving away from pilot lights, most home heating systems have them. So, if your furnace isn’t turning on or getting gas, then the flow of gas to this component may be interrupted. This could be due to a faulty gas line or a strong gust of wind. Either way, once the pilot light has gone out, it will need to be re-lit in order to restore heat into the premises.
While the side panel of the unit (or user manual) often includes instructions for this process, it’s always best to have a specialist handle gas issues. There are a number of concerns worth considering when the pilot is out and the gas is still on. Even if you think you’ve aired out the property, looming effects can present hazards.
3. Electrical Problems Are the Culprit.
Similar to the emergency shut off switch, a tripped breaker is another reason why a furnace won’t turn on. Those of you that rarely use your heating system have more than likely experienced this type of electrical issue before. Most of our customers don’t even think to check their breaker because their furnace is powered by gas. But nearly every heater we’re aware of needs an electric current to turn on!
One of the best ways to prevent this occurrence is to invest in a whole home surge protector.

4. A Gas Leak to Heater Lines.
Like we mentioned before, gas leaks can be extremely problematic. If your furnace isn’t turning on, but the pilot is on and gas is flowing, then turn it off. Natural gas is an inflammable mixture of hydrocarbon gases that’s colorless, odorless, and tasteless when it comes out of the ground. This is difficult to sense if you rarely use your heater. If at any point you think you smell a sulfuric odor (and you don’t have a salt water pool), then you ought to evacuate the residence immediately.
5. Additional Gas Line Concerns.
If your furnace isn’t turning on at this point, then you may have a problem with your gas line. You can easily eliminate this hypothesis by testing your other gas-burning appliances. If the stove or your water heater won’t turn on then the gas line itself is the real culprit. Taking the time to inspect the entirety of your system before calling a professional may save you a lot of time and money due to misdiagnosis. Just don’t forget the risks that come with DIY management.
6. Programmable Thermostat Error Message.
The only way a furnace can communicate with you is by reporting thermostat errors. These notify a homeowner when something is wrong with the system and helps them remedy the situation. Obviously if you’ve received one of these then you should know a problem exists. The main benefit of this feature is to help you find the source.

Sometimes, a simple error or altered temperature setting could be the reason why your furnace isn’t turning on or getting gas. A minor adjustment will get you back up and running in no time. Keep in mind, an analog furnace does not come equipped with thermostat error messages, but most electric models do.
7. Faulty or Failing Flame Sensors.
Your ignition sensor, also known as a flame sensor, is a safety feature that tells your heating system if it’s burning gas or not. Are you trying to turn the furnace on but it’s only making a clicking noise? If so, this means the pilot is not igniting. In most cases, this is because of a faulty sensor – similar to an ignition switch on a motor vehicle.
8. A Blocked or Dirty Furnace Filter.
Internal damage to your heating system is another possible reason why your furnace isn’t turning on or getting gas. In some cases, dirty air filters within the unit create havoc. Dust and debri can easily impact heating fans, exchangers, pilot lights, pressure switches, gas valves and other components of the system. So make sure you’re changing them regularly or expect a problem.
9. Blocked Airflow From the Intake.
In order for a furnace to operate and function properly, it’s always going to need sufficient airflow. When a dirty filter isn’t the cause, a blocked intake should be immediately inspected. This definitely keeps the furnace from starting. If you’re going to pay for routine maintenance, make sure the technician is inspecting these areas of your heating system.

10. Condensation Pump Isn’t Working.
Like your favorite slushie in the middle of the summer, heating and cooling systems sweat in the Arizona climate. Because of this, heating systems come with condensation pumps to keep your equipment from pooling up water. If it is not working properly, then you could find it hindering gas flow.
11. Furnace Fan Problems.
The primary responsibility of a furnace blower’s motor is to pull heat from the system and circulate it throughout the residence. When the blower motor is working properly, a green light in the little plastic window should be flashing. This is located on the side of the furnace. If it’s doing anything but blinking green, then the motor is on the fritz. In order to restore it, you’ll need to call a qualified technician.
Get Your Furnace Turned Back On This Winter!
At Canyon State, we’ve been helping homeowners just like you with their HVAC needs for over three decades. We go the extra mile to ensure that every single one of our customers are completely satisfied with service and performance. Our family culture cares if you remain cool and comfortable in the summer and toasty warm in the winter.
We’ve put in a lot of time in building an impeccable reputation that’s based on traditional values. In our eyes, the customer should always be our highest and only mission. That’s why our highly trained team takes pride in quality and safety measures. If your furnace isn’t turning on or getting gas, we’d love to help. Hopefully we’ll see you soon!