Furnace Smells Like Gas or Burning? What to Do Right Now
TLDR Quick Answers What should I do if I smell gas near my furnace? Leave the house now with everyone and the pets, touch no light switches, and call 911 or your gas utility from outside. Is a burning smell normal when the furnace first turns on? Yes. Dust burns off the heat exchanger at […]
Furnace Making Noise? What Banging, Squealing and Rattling Actually Mean
TLDR Quick Answers What does a furnace banging noise mean? A loud bang at startup usually means delayed ignition. Gas builds up for a second, then burns all at once. Why does a furnace screech or squeal? A worn blower belt on older furnaces, or failing blower motor bearings on newer ones. Both worsen with […]
Furnace Short Cycling: Why Your Furnace Keeps Turning Off
TLDR Quick Answers What is furnace short cycling? The furnace turns on, runs a few minutes, shuts off before the house reaches the set temperature, and repeats all day. What causes a furnace to keep shutting off? Overheating from a clogged filter or blocked vents is the most common cause. A dirty flame sensor, thermostat […]
Furnace Leaking Water: What Is Normal, What Is an Emergency
TLDR Quick Answers Why is water pooling under my furnace? On a high efficiency furnace, a clogged condensate drain line or trap is the most common cause. The furnace makes water by design, and the drain path is blocked. Is it normal for a furnace to drain water? Yes, for a condensing furnace rated 90 […]
Why Is My Furnace Blowing Cold Air? 7 Causes Ranked
TLDR Quick Answers Why is my furnace blowing cold air? The blower is running but the burners are not making heat, most often because of a failed ignitor, a dirty flame sensor, or an overheating limit switch. What should I check first? The thermostat fan setting and the air filter. Fan set to AUTO and […]
Furnace Not Turning On? 9 Checks Before You Call a Technician
TLDR Quick Answers What should I check first if my furnace will not turn on? The thermostat, the breaker, the furnace power switch, and the air filter. Those four checks revive a large share of dead furnaces. What is the most common cause of a furnace that will not start? A cracked hot surface ignitor. […]
Furnace Flame Sensor Cleaning: How to Clean It (and When to Call Instead)
TLDR Quick Answers What is a furnace flame sensor? A thin metal rod that confirms the burner actually lit. If it cannot detect a flame, the furnace shuts the gas off within seconds. Why does a furnace start then shut off after a few seconds? A dirty flame sensor is the most common cause. Oxidation […]