Safety note: This is general information only, not professional advice. Only do what you can do safely: turn off power before touching equipment, follow the manufacturer's instructions, and leave anything involving gas, electrical wiring, or refrigerant to a licensed professional. Any action you take is at your own risk — see the disclaimer.
Stop and call for help instead if you smell gas (leave the building and call your gas utility or 911 from outside), if a carbon monoxide alarm is going off (get everyone outside and call 911), or if you see scorch marks, smell burning, or hear loud banging.
1. Check the thermostat
Make sure it's set to Heat and the set temperature is a few degrees above the room temperature. If the screen is blank, replace the batteries (if it uses them). For smart thermostats, check for an active schedule, "eco" or away mode, or a lost Wi-Fi connection that's holding an old setting.
2. Check the furnace power switch and breaker
Most furnaces have a switch that looks like an ordinary light switch, mounted on or near the unit — often at the top of the basement stairs, where it's easy to flip off by mistake. Make sure it's on. Then check your electrical panel for a tripped breaker. Reset it once; if it trips again, stop and call.
3. Make sure the front panel is seated
The blower compartment door presses a safety switch. If the panel was removed to change a filter and isn't pushed fully back into place, the furnace won't run.
4. Replace a clogged air filter
A badly clogged filter chokes airflow, the furnace overheats, and a high-limit safety switch shuts the burners off — often showing up as the furnace running briefly and then blowing cold air. Put in a fresh filter with the airflow arrow pointing toward the furnace.
5. Confirm the gas supply
Look, but don't touch: the gas shutoff valve on the pipe feeding the furnace is normally open, with its handle running parallel to the pipe. If the handle is crossways to the pipe, or your other gas appliances (stove, water heater) aren't working either, don't turn any valves or relight anything yourself — call us or your gas utility. If you smell gas, leave the building and call from outside.
6. Check the condensate drain (high-efficiency furnaces)
If your furnace vents through white PVC pipes, it makes water. A clogged drain line or a condensate pump that's full or failed will trip a safety switch and shut the furnace down. Look for water around the furnace or a pump reservoir that's full.
7. Read the blinking status light
Most modern furnaces have a small LED on the control board, visible through a little window in the lower panel. Count the blinks and compare them to the code chart on the inside of the door. Even if you can't fix it, telling us the code when you call speeds up the repair.
8. Clear snow from outside vent pipes
After a heavy Northeast PA snowfall or drifting wind, the intake and exhaust pipes on a high-efficiency furnace can get buried or iced over, and the furnace will shut itself off. Gently clear snow and ice from around both pipes outside.
A note on reset buttons
Don't keep resetting a furnace or boiler that keeps shutting down — it's telling you something is wrong. If you have an oil burner with a red reset button, never press it more than once. If the burner doesn't stay running, don't press it again — call for service. Pressing it repeatedly can pump excess oil into the combustion chamber and create a dangerous situation.
Still no heat?
If none of these got the heat back on, call or text 570-983-9747 — we offer 24/7 emergency service across Lackawanna, Wayne, and Luzerne Counties. Have the furnace's make, the blink code (if any), and what you've already checked ready. Learn more about our furnace and boiler repair.
Boiler instead of a furnace? Steps 1, 2, and 5 apply the same way. Also check the pressure gauge: most residential hot-water boilers sit around 12–15 psi when cold.
Disclaimer
The information on this page is provided for general informational purposes only. It is not professional advice for your specific equipment, building, or situation, and reading it does not create a customer or contractor relationship with Affordable AC & Refrigeration Services LLC.
Heating, air conditioning, refrigeration, gas, and electrical equipment can cause serious injury, death, fire, or property damage if handled improperly. Always follow your equipment manufacturer’s instructions and safety warnings, turn off power before touching any equipment, and do not attempt any work involving gas lines, electrical wiring, refrigerant, sealed components, or combustion and venting — that work should be performed only by a qualified, licensed professional. If you smell gas or a carbon monoxide alarm sounds, leave the building immediately and call 911 or your gas utility from outside.
Any action you take based on this information is strictly at your own risk. Information may be incomplete or change over time and is provided “as is,” without warranties of any kind. To the fullest extent permitted by law, Affordable AC & Refrigeration Services LLC and its owners, employees, and contractors are not liable for any injury, loss, or damage to persons or property arising from the use of, or reliance on, this information. Read our full website disclaimer.