Your Furnace Stopped Working — Now What?
It's January in South Bend. The temperature outside is in the teens, and your furnace just quit. Before you panic and call for furnace repair, there are a few simple things you can check yourself — and some of them take less than two minutes. You might save a service call fee. More importantly, you'll have better information when you do call.
This guide walks you through the basics so you know exactly when to DIY and when to pick up the phone.
Check the Thermostat First
It sounds obvious, but the thermostat is the most overlooked culprit. Make sure it's:
- Set to Heat, not Cool or Fan Only
- Set above the current room temperature
- Powered on (dead batteries kill more thermostats than you'd think)
- Not stuck on a schedule that's fighting your manual override
If your thermostat display is blank, replace the batteries before anything else. If it powers back on and your furnace kicks on within a minute or two, you're done.
Check Your Air Filter
A clogged air filter is one of the most common causes of furnace shutdowns in South Bend homes — and it's 100% preventable. When airflow gets restricted, the furnace overheats and trips a safety switch called the high-limit switch. It shuts down to protect itself.
Pull your filter out and hold it up to a light. If you can't see light through it, it's time for a new one. Replace it, reset your furnace (usually a power switch near the unit), and see if it comes back on.
Filters should be replaced every 1–3 months, depending on your home, pets, and usage. If you can't remember the last time you changed yours, it's probably overdue.
Check Your Circuit Breaker
Furnaces run on electricity even if they use gas for heat. A tripped breaker can cut power to the unit entirely. Go to your electrical panel and look for any breaker that's in the middle position (tripped) rather than fully ON or OFF.
Flip it fully off, then back on. If it trips again immediately, do not keep resetting it — that's a sign of an electrical issue that needs a professional.
Check the Furnace Power Switch and Drain Line
Most furnaces have a power switch on or near the unit — it looks like a light switch and is sometimes accidentally flipped off. Make sure it's in the ON position.
Also, if you have a high-efficiency furnace (90%+ AFUE), it has a condensate drain line. If that line gets clogged, the furnace will shut itself off as a safety measure. Look for a small PVC pipe near the base of your unit and check if there's standing water or visible blockage.
Check the Pilot Light (Older Units)
If your furnace is older and uses a standing pilot light, check to see if it's lit. If it's out, follow the relight instructions on the furnace label carefully. If it won't stay lit or you smell gas, stop and call immediately — that's not a DIY situation.
Most furnaces installed after 2000 use electronic ignition, so this step won't apply to you.
When to Stop Troubleshooting and Call a Pro
If you've worked through everything above and your furnace still isn't running, it's time to call for professional furnace repair in South Bend, IN. Some issues — cracked heat exchangers, failed ignitors, gas valve problems, or motor failures — require licensed HVAC technicians with the right tools and training.
Call immediately if you notice:
- A yellow or orange pilot flame (should always be blue)
- The smell of gas anywhere near the unit
- Carbon monoxide detector alarms
- Loud banging, screeching, or grinding sounds
- The furnace cycling on and off repeatedly without heating
These aren't inconveniences — they're safety issues.
Goff Heating & Plumbing Has You Covered in South Bend
When the checks above don't solve it, Goff Heating & Plumbing is ready to help. We provide honest, reliable furnace repair for homeowners across South Bend, IN and the surrounding area. No upsells, no guesswork — just qualified technicians who diagnose the problem and fix it right.
Don't wait out the cold. Contact Goff Heating & Plumbing today to schedule your furnace repair and get your home back up to temperature.