What should I do if my furnace stops working?

Start by checking for simple causes like a dirty filter, tripped breaker, or an extinguished pilot light. If the furnace still won't run—especially if you see soot or a yellow burner flame—shut the system off and contact a licensed heating technician.

Why is my furnace running but not heating?

Restricted airflow from a clogged filter or blower issue often prevents proper heating. Dirty burners or ignition problems can also reduce performance. If changing the filter doesn’t help, schedule a furnace inspection.

Is it dangerous if my furnace has a yellow flame?

Yes. A yellow flame can indicate incomplete combustion or a cracked heat exchanger, which may leak carbon monoxide. Turn off the furnace and call a professional immediately.

Why does my furnace keep tripping the breaker?

Repeated breaker trips usually signal an electrical issue inside the furnace, such as a failing blower motor or shorted wiring. Avoid resetting it repeatedly and call a technician.

When should I repair versus replace my furnace?

If your furnace is older, needs frequent repairs, or your utility bills are rising, replacement may be more cost-effective. A professional can assess long-term repair vs. replacement costs.

How to care for your furnace

March 19, 2013

If your furnace stops working, start by checking simple issues like a tripped breaker, dirty filter, or an extinguished pilot light. If none of these solve the problem—or if you see warning signs like soot or a yellow burner flame—turn the system off and call a licensed heating technician immediately.

TL;DR

Many furnace failures have simple causes such as dirty filters or tripped breakers.
Yellow flames or soot can signal dangerous carbon monoxide risks—shut it down and call a pro.
Pilot issues and blown fuses require a trained technician to fix safely.
Regular heating system tune-ups prevent breakdowns and catch problems before they become emergencies.

Regular Tune-Ups

Your furnace should be tuned up and inspected at least once a year. A tune-up includes filter replacement and system cleaning to improve efficiency and reduce wear and tear. Inspections also catch developing problems—especially safety issues.

Warning Signs to Pay Attention To

If your burner flame is yellow instead of blue, you notice soot around the furnace, or you see moisture building up on windows or walls, there may be a crack in the heat exchanger. This can cause carbon monoxide leaks. Turn off the system and call a licensed heating professional immediately.

If your carbon monoxide alarm sounds, evacuate your home right away and call 911. Do not re-enter until emergency responders say it is safe.

If Your Furnace Stops Working

Here are the most common reasons a furnace shuts down:

Tripped Circuit Breaker or Blown Fuse

A single tripped breaker isn’t unusual, but repeated tripping suggests an internal electrical issue. Call a heating technician for repair.

Blown Internal Fuse

Furnaces contain internal fuses that protect components from electrical surges. A technician can safely replace the fuse and diagnose the cause.

Pilot Light Is Out

Older gas furnaces rely on pilot lights. If the pilot goes out, the furnace won’t ignite. Contact a licensed contractor to relight and inspect the ignition system.

Dirty Filter

A clogged filter reduces airflow and strains your furnace. If your home isn’t warming up properly, start by replacing the filter.

When Should You Replace Your Furnace?

A malfunctioning furnace can be unsafe and inefficient. If your system needs frequent repairs or your utility bills are rising unexpectedly, talk with a heating contractor about whether a replacement may be the better long-term choice.

Categories: Heating