Furnace Not Working? 11 Things to Check Before You Call for Furnace Repair in Sherwood Park

Furnace Not Working? 11 Things to Check Before You Call for Furnace Repair in Sherwood Park The first real cold snap in Sherwood Park is when most furnaces show their problems. You turn up the thermostat and get nothing, or cold air, or a furnace that starts and stops every few minutes. The good news is that a lot of “broken” furnaces aren’t broken at all. A tripped switch, a clogged filter, or a vent blocked by frost can stop a perfectly healthy furnace. This guide walks you through the safe checks you can do yourself, explains what each symptom usually means, and tells you exactly when it’s time to call a professional. Quick answer: why is my furnace not working? The most common reasons a furnace stops working are: a thermostat setting or dead batteries, a tripped breaker or furnace power switch, a clogged air filter, a loose furnace door panel, a closed gas valve, or a blocked exhaust or intake vent. Check these first. If the furnace still won’t heat, or shows a flashing error light, a failed part like the flame sensor, igniter, or control board is likely, and a licensed technician should diagnose it. Safety first: stop and call right away if… You smell gas (rotten eggs). Don’t touch light switches or the thermostat. Leave the house, then call ATCO Gas’s 24-hour emergency line at 1-800-511-3447 or 911 from outside. Your carbon monoxide alarm goes off. Get everyone outside and call 911. Never ignore a CO alarm, even if nobody feels sick. You hear a loud bang or boom when the furnace starts. This can mean delayed ignition. Shut the furnace off and call a technician. You smell burning plastic or electrical odours, or see scorch marks. Turn the furnace off at the switch. If none of these apply, you can safely work through the checklist below. Furnace troubleshooting chart Symptom Most likely cause Try this first Call a pro if… Won’t turn on at all Thermostat, power, door switch Check settings, batteries, breaker, panel Still dead after checks Blowing cold air Fan set to “ON”, dirty filter, ignition or flame sensor issue Set fan to “AUTO”, change filter Cold air continues Turns on, then shuts off Dirty filter, flame sensor, blocked vents Change filter, clear vents Keeps short-cycling Flashing light on furnace Error code Count the flashes, check the chart on the door Code points to a part failure Burning dust smell First start of the season Let it run for an hour Smell stays or smells electrical Some rooms cold Closed vents, blocked returns, dirty filter Open vents, clear furniture Rooms stay cold Loud banging or squealing Ignition or blower problem Turn it off Right away 11 things to check when your furnace isn’t working 1. Check the thermostat settings Make sure the thermostat is set to HEAT, not COOL or OFF, and set at least 2–3 degrees above the current room temperature. On a programmable or smart thermostat, check that a schedule or “away” mode isn’t holding the temperature down. 2. Replace the thermostat batteries A blank or dim screen often means dead batteries. Many thermostats won’t send a heat call on low batteries, even if the screen still shows something. 3. Check the breaker and furnace power switch Your furnace has a switch that looks like a regular light switch, usually on or near the furnace. It gets flipped off by accident more often than you’d think. Also check your electrical panel for a tripped furnace breaker. If the breaker trips again right after you reset it, stop and call a technician. 4. Make sure the furnace door is closed tightly Furnaces have a safety switch behind the front panel. If the panel isn’t fully seated after a filter change, the furnace won’t run. Push it firmly into place. 5. Change the air filter A clogged filter is one of the top reasons furnaces overheat, shut off early, or blow weak air. As a general guide: Standard 1-inch filters: check monthly and replace every 1–3 months. Thicker 4–5 inch media filters: replace every 6–12 months. Homes with pets, renovations, or a lot of dust need more frequent changes. 6. Confirm the gas valve is open Find the gas line going into the furnace. The handle on the shut-off valve should line up with the pipe (open), not sit across it (closed). If other gas appliances like your stove or water heater aren’t working either, contact your gas provider. 7. Read the blinking status light Most modern furnaces have a small window with an LED light. The number and pattern of flashes is an error code. Count them, then match the code to the chart on the inside of the furnace door. Write the code down, because it helps a technician arrive with the right part. 8. Clear snow and frost from the exterior vents (a big one in Alberta) High-efficiency furnaces vent through two white PVC pipes on the outside wall. After a heavy snowfall, drifting snow, or a deep freeze, these pipes can get blocked with snow or frost. The furnace then shuts itself off for safety. Gently clear snow and ice from around both pipes, keep about a foot of clear space around them, and never cover them. If they ice up every winter, the venting may need to be corrected by a professional. 9. Check for a frozen or clogged condensate line High-efficiency furnaces produce water that drains through a small plastic tube or pump. If the line is clogged, or freezes where it runs through a cold space, a safety switch can shut the furnace down. Look for water around the furnace, or a condensate pump that’s full or not running. 10. Listen for the ignition sequence When the furnace starts, you should normally hear the inducer fan, then see the igniter glow or click, and then see the burners light. If it tries to light and stops after a few seconds, a dirty or failing flame