It's That Time: Time To Schedule Your Winter Furnace Tune-Up. Contact Us

513-984-HEAT

(4328)

Common Furnace Problems Found When You Try to Turn It On

A surprising number of people discover problems when they try to turn on their furnace for the winter, whether it fails to start or dies shortly after heating up.

Let’s look at some of the most common furnace issues people find when they turn on the heating system for the first time in ages. We’ll share a few tips on how and when you can fix them yourself and tell you when you need to call a reputable Cincinnati HVAC company.

The Furnace Isn’t Heating Your Home

Before you panic about the furnace not heating your home, check the thermostat. No, really. It is amazing how often someone freaks out about a furnace not heating up when the truth is they set it to “fan” instead of “heat”. Or the furnace isn’t heating your home because someone set the temperature so low the furnace hasn’t engaged yet. In a few cases, the thermostat is throwing out an error and needs to be fixed. Replacing a thermostat is generally cheaper than fixing a furnace.

Suppose the thermostat is fine. The next matter is the furnace itself. If the furnace isn’t getting enough air, it can’t produce much hot air to heat up the rest of the home. That may be solved by replacing the air filters, though it may be due to leaky ducts, as well. Another possibility is that the furnace isn’t on at all. If a safety sensor shut it down, your fans are going but the furnace isn’t. If you’ve had a gas appliance serviced or replaced recently, the gas supply to the home may have been turned off. We’re going to assume you know whether or not you’ve paid your gas bill.

Once in a while, the furnace needs to be reset to clear error messages and/or the power restored through the breaker box. This may occur because someone turned off the furnace to service it at the end of last season and never restored power. Or a circuit breaker may have tripped when you tried to start it up. In other cases, the solution is replacing burned out fuses at the fuse box. However, if there are repeated electrical issues, turn the furnace off and call for service.

It Dies Shortly After Startup

There are several potential causes for a furnace starting up and then dying. A common cause is a lack of airflow. You can determine this rather quickly yourself by checking the air filters. If they’re gray or black, they need to be replaced. Take the opportunity to check the air intake ducts. You may find out the furnace is dying because dead leaves or other debris is blocking the air intake duct; cleaning away debris can fix this. In some cases, gaps in the air intake duct allow leaves to get sucked in. That trips safety systems that shut down the furnace. This may be solved by replacing the grate and cleaning out the debris. Another potential reason why furnaces may startup and die is faulty sensors. If the unit thinks it is overheating because of a bad temperature sensor, it will shut down. Bad pressure sensors can shut down the furnace though nothing is wrong. If flipping the sensors and resetting the furnace doesn’t solve the problem, you should call for service. After all, the sensors may be right. For example, the motor may be shorting out and overheating, or there’s a mechanical problem you don’t know how to diagnose.

Occasionally, gas furnaces die because moisture buildup is killing the flame. This is more likely if you hear gurgling and water noises after you start up the furnace. Try cleaning the drain or trap, so that any moisture in the system can escape. If this isn’t good enough or the problem reoccurs, call for service. Too much moisture could mean there is a problem in the ducts, the pipes or the furnace itself.

The Noise Is Horrible

If your furnace is making a whistling noise, the first thing to check is the air filter. If you pull out the filter and the whistling stops, that’s the cause. If your furnace makes a loud boom after you start it, the noise may be due to delayed ignition. That’s potentially dangerous; turn off the furnace and call for a professional evaluation. General rattling and vibration aren’t bad per se. You could put rubber or cork pads under the furnace to reduce it, and duct tape can hold loose equipment together. If motors are grinding or vibrating badly, call an HVAC repair service. Banging in the furnace due to pressure changes also requires a professional. Rumbling may mean there is a problem with your burner; if it persists, call for service. A general hum is normal, but if there’s an extra high whine or the noise is different than you remember, go ahead and have it checked out. You’d rather get capacitors and transformers replaced now than have the furnace go out when it is even colder outside.

If you are having issues with your furnace and you would like a reputable and professional HVAC company in Cincinnati to take a look at it, please contact Pinnacle Air Solutions today.

© 2025 Pinnacle Air Solutions

Custom Website by WeGo Unlimited
Affordable Cincinnati Website Design

513-984-HEAT

(4328)
MENU