Furnace Not Working? A Minnesota No-Heat Checklist
When the furnace quits in a Minnesota winter, the clock is running: an average house drops a degree every hour or two below zero, and pipes begin to freeze around 32°F inside the walls. Here is how to check a furnace that is not working, and what to do while you wait for heating repair.
Quick checks that fix half of no-heat calls
- Thermostat: set to HEAT, set point above room temperature, fresh batteries.
- Furnace switch: the light switch on or near the furnace is often turned off by mistake.
- Breaker: even a gas furnace needs electricity for the blower and control board.
- Filter: a plugged filter overheats the furnace and trips the high-limit switch, which shuts the burners off. This is the number one cause of furnace short cycling.
- Furnace door: the blower-door safety switch will not let the furnace run if the panel is loose.
- Intake and exhaust pipes: on high-efficiency furnaces the white PVC pipes outside can be blocked by snow drifts or frost. Clear them.
- Condensate drain: a frozen or clogged drain line trips a float switch and locks the furnace out.
Read the error code
Most furnaces have a small LED behind the lower panel that flashes a code. Count the flashes and check the chart on the inside of the door. Common ones: flame sensor (clean it), pressure switch (blocked vent or bad inducer), ignitor (replace), limit switch (airflow).
What the technician will fix
Dirty flame sensors, failed hot-surface ignitors, bad pressure switches, inducer motors, blower motors, capacitors, control boards and gas valves cover most no-heat repairs. Our trucks stock all of them.
Protect the house while you wait
Open cabinet doors under sinks on exterior walls, let faucets drip, close off unused rooms, and run space heaters in the rooms you are in — never unattended. If you smell gas, leave and call from outside.
24 hour heating repair is available statewide, including Minneapolis, Saint Paul, Duluth, Rochester and Bloomington.