Inducer Motor Repair & Replacement
Professional draft inducer motor diagnosis and replacement for all furnace brands. Expert pressure switch testing and combustion safety verification.
What is an Inducer Motor?
The draft inducer motor (also called induced draft blower) creates negative pressure in the heat exchanger to safely exhaust combustion gases. Modern high-efficiency furnaces rely on the inducer motor to establish proper draft before the burners ignite.
Critical Safety Component
A failed inducer motor prevents your furnace from operating. This is a safety feature — if proper draft cannot be established, the furnace will not ignite to prevent carbon monoxide buildup and combustion spillage.
Inducer Motor Function
During the furnace start sequence, the inducer motor runs first to purge the heat exchanger and establish proper draft. Only after the pressure switch confirms adequate airflow will the control board energize the ignition system.
Typical Start Sequence
- Thermostat Calls for Heat: Control board receives signal
- Inducer Motor Starts: Begins drawing air through heat exchanger
- Pressure Switch Closes: Confirms adequate draft established
- Ignition System Energizes: Hot surface igniter or spark ignition activates
- Gas Valve Opens: Burners ignite
- Blower Motor Starts: After heat-up delay, blower delivers warm air
Common Inducer Motor Failures
Worn or Seized Bearings
Inducer motors operate in hot, corrosive exhaust gases. Bearings wear over time, causing squealing, grinding noises, or complete seizure. Worn bearings increase amp draw and create excessive vibration.
Pressure Switch Lockout
If the inducer motor runs but cannot create sufficient negative pressure, the pressure switch will not close and the furnace will not ignite. This can be caused by a weak motor, blocked vent piping, or a failed pressure switch.
Motor Winding Failure
Electrical winding failure prevents the motor from running entirely. The furnace control board may display a fault code, or you may hear the inducer attempt to start but fail to spin.
Cracked or Damaged Housing
Physical damage to the inducer housing creates air leaks that prevent proper draft. The entire inducer assembly must be replaced if the housing is compromised.
Pressure Switch Relationship
The pressure switch is directly connected to the inducer motor operation. It acts as a safety proving device to confirm adequate draft before allowing ignition.
Pressure Switch Diagnostics
Check pressure switch tubing for blockage, kinks, or water accumulation
Verify switch closes when inducer creates proper draft
Use manometer to measure actual negative pressure vs. switch rating
Inspect vent piping for blockage, improper slope, or restrictions
Inducer Motor Replacement Process
Proper inducer motor replacement requires careful disassembly, correct motor selection, and thorough combustion safety testing after installation.
Our Replacement Procedure
- System Shutdown: Turn off furnace and gas supply
- Disassembly: Remove burner assembly and disconnect inducer wiring
- Old Motor Removal: Disconnect pressure switch tubing, remove mounting hardware
- Gasket Inspection: Replace inducer gasket to prevent air leaks
- New Motor Installation: Mount OEM or equivalent inducer assembly
- Pressure Switch Reconnection: Connect tubing, verify no leaks or blockage
- Electrical Connection: Wire motor per diagram, verify polarity
- Reassembly: Reinstall burner assembly with proper sealing
- System Testing: Verify inducer operation, pressure switch closure
- Combustion Analysis: Test for safe, complete combustion
Draft and Combustion Safety
After inducer motor replacement, we perform comprehensive combustion safety testing to ensure proper venting and safe operation.
Draft Testing
- • Measure negative pressure at heat exchanger
- • Verify pressure switch activation point
- • Check vent system for proper slope and termination
- • Confirm adequate draft throughout burn cycle
Combustion Testing
- • Measure CO (carbon monoxide) levels
- • Check O₂ (oxygen) percentage
- • Verify complete combustion
- • Test for spillage at draft hood
Why Choose FurnaceMotor.ca for Inducer Service
Trained in proper venting and combustion analysis
Genuine parts for all furnace brands
Complete draft system diagnostics
All work meets BC building code requirements