You might not need your gas furnace for most of the year in the Phoenix area, but it can get chilly in the evenings and at night from November to March, and that’s when you’ll be looking for your heating system to deliver reliable warm air to heat your home.

If your home has a heat pump, cold air momentarily coming out of your vents when your system starts up isn’t a cause for alarm—it’s part of normal heat pump operation. But if your furnace isn’t blowing hot air or heating, you likely have an HVAC problem on your hand. Here’s what could be going on if your furnace isn’t heating, along with three DIY solutions to help you avoid emergency furnace repair for your Phoenix, Chandler, Scottsdale, Tempe, or Mesa home.

1. Your Furnace Thermostat Is Set Incorrectly

Some programmable thermostats can be a little confusing to read—if the fan on your thermostat is set to “ON,” that means everything’s good, right? Actually, the “ON” setting means that only your fan is running, and not the furnace itself. “AUTO” is the correct setting—that means the fan will only run when the furnace is on. If your furnace won’t turn off and is blowing cold air, the first place you should check is your thermostat—it’s an easy fix!

2. Your Pilot Light Has Gone Out

While newer models have electronic ignition systems, older furnace models used a standing pilot light—a small flame that never goes out—to start the gas burner when your furnace turned on. If your vents are blowing cold air when the heat is on, it could be because your pilot light has blown out and your furnace won’t ignite. We generally don’t see many furnaces here in the Phoenix metropolitan area that use pilot lights, but in the rare instance you have this – keep reading!

It isn’t difficult to relight a pilot light—often a furnace will have step-by-step instructions on the side of the unit. But if your pilot light isn’t staying lit, you could be dealing with:

  • A faulty thermocouple
  • A pilot orifice that’s covered with dirt and debris
  • Not enough gas to keep the flame lit

If your pilot light goes out once or twice but you’re able to relight it, it could have just been a draft. But if it repeatedly goes out, and your furnace is blowing cold air constantly, it’s probably time to call for professional HVAC assistance.

3. Your Air Filters Are Dirty

Your furnace filters help trap dust, dirt, pet dander, mold spores, and other unwanted particles from circulating in your indoor air and from gumming up your furnace. But they need to be changed regularly—if they’re left for too long, they’ll collect enough particulate matter that it will eventually start to restrict airflow in your forced air system.

When that happens, your furnace’s heat exchanger is in danger of overheating, and as a safety precaution, a limit switch will be triggered and the furnace burners will automatically turn off to avoid a cracked heat exchanger (which is a costly problem to fix). Air filters can be inspected and replaced in seconds—so if you have cold air coming through the vents when your furnace is on, make sure you don’t need new air filters.

When Should You Call an HVAC Company for Furnace Help?

So you’ve gone through each of the steps above—checking the thermostat, your pilot light, and air filters—and your furnace is blowing cool air still. Now’s the time to reach out to a local heating company near you for heating repair that will fix the problem. At Ideal Energy, our trained and certified HVAC technicians service all makes and models, and our top priority is identifying the issue quickly and finding a long-lasting solution, not band-aid fixes that will have you on the phone looking for help again in a few weeks.

We know how frustrating it can be to reach out to an HVAC company only to have them spend the entire service call trying to upsell you on an expensive new unit that you don’t think you need. That’s why the Ideal Energy team treats your HVAC system as if it were our own—and whether it’s a simple furnace repair or we actually believe your best solution is furnace replacement, we’ll explain our reasoning and work within your budget to find the best heating solution for your Arizona home.

Cold air coming from your vents when the heat is on? Call 480-839-0082 or contact us today for expert furnace advice and repair from Ideal Energy.