Furnace Troubleshooting – Top 5 Problems & Solutions


When winter hits the Baltimore area, the last thing you want to deal with is a furnace that’s on the fritz. Before you call for repairs, here are some furnace troubleshooting tips from the team at Supreme Service Today that may solve your furnace problem without requiring a service call.

My Furnace Won’t Turn On

Check the Thermostat Settings

First, make sure the thermostat is set to “Heat” not “Cool”. Sounds funny, but it’s easy to overlook this time of year. Next, try setting the temperature at least 5 degrees warmer than the current room temperature. If you still don’t hear the fan turn on, bump your thermostat up to 90 degrees and listen for the fan to turn on again.

Check the Electrical Panel

Is power getting to your furnace? Check the breaker box (usually located in the basement or garage) and make sure that the switch hasn’t tripped. Also, check that the furnace power switch is flipped to “on.” The power switch looks like a regular light switch. One other switch to check is the blower motor switch. Look for a switch near the motor’s housing and try resetting it.

Check the Filter

A common troublemaker for furnaces is a dirty filter. Some of today’s high-efficiency furnaces will shut down if the filter gets too dirty. Most filters should be changed monthly, so double check that your filter is clean and replace it if not.

Check for Airflow

Check all of the registers in your home to ensure that they are open and not blocked. Check your ductwork for any disconnections or leaks, which will also hinder your furnace’s performance.

Furnace Is Blowing Air, but It’s Cool Air

Check the Condensate Drain

The condensate drain is a clear hose that extends from your unit that allows excess moisture to drain away from it. It can become clogged or restricted by algae. Clean out or flush the drain blockage to troubleshoot this issue.

Trouble – Furnace Is Making Strange Noises

Call a Heating and Cooling Technician

Strange noises can mean many different things. It could be a loose or broken belt, a broken fan motor, a broken or loose part. Whether it’s clanking, squealing, or thumping, your furnace should not make unusual noises. In this case, call Supreme Service Today so one of our technicians can properly diagnose the problem and fix it.

If you try all of these tips and still have trouble, contact us online or call us at (410) 846-6751 today and one of our technicians will have that furnace up and running in no time!