Description
Lennox 38M64 Pressure Switch Overview
The Lennox 38M64 is an OEM replacement pressure switch designed to protect your furnace by monitoring and verifying proper draft pressure during operation. With a calibrated set point of 1.95″ WC (water column), this switch confirms that the inducer motor is creating adequate negative pressure before allowing the ignition sequence to proceed — a critical safety function in modern gas furnaces.
Key Features
- OEM Lennox replacement pressure switch — SKU 38M64
- Calibrated set point: 1.95″ WC (water column)
- Monitors inducer/draft pressure to ensure safe furnace operation
- Prevents ignition if proper draft pressure is not established
- Direct OEM replacement for compatible Lennox furnace models
- Reliable performance engineered to Lennox quality standards
How It Works
The pressure switch is a normally open (NO) safety device that closes when the inducer blower generates the correct negative pressure within the flue system. If the required pressure threshold of 1.95″ WC is not reached — due to a blocked flue, failed inducer motor, or other issue — the switch remains open, preventing the furnace from firing and protecting against unsafe operating conditions.
Application
- Designed for use in compatible Lennox gas furnaces
- Ideal for HVAC technicians performing service, maintenance, or repair
- Direct drop-in replacement to restore proper furnace safety controls
Why Choose OEM?
Using a genuine Lennox OEM pressure switch ensures the correct set point, electrical ratings, and fitment for your specific equipment — minimizing callbacks and ensuring long-term reliability.
Reviews
There are no reviews yet.