The Lennox 27P95 (Mars 33243) electric heat sequencer relay is a dependable single-pole, single-throw (SPST) relay designed for sequencing electric heaters in Lennox residential and light commercial HVAC systems. It features adjustable ON and OFF delay timing to ensure smooth and safe heat sequencing.

Key Features:
• SPST (single pole, single throw) relay configuration for straightforward operation
• ON delay range 1–60 seconds to stage heat elements sequentially
• OFF delay range 1–45 seconds for controlled element shutoff
• 24-volt coil compatible with standard control circuits
• Designed as a direct replacement for Lennox 27P95 and Mars 33243 applications
• Helps maintain even heat distribution and protects heating elements from electrical stress

 

Technical Specifications:

• Part Number: Lennox 27P95 / Mars 33243
• Relay Type: Electric heat sequencer relay
• Poles/Throws: SPST
• ON Delay: 1–60 seconds
• OFF Delay: 1–45 seconds
• Coil Voltage: 24 Volts (low voltage control)
• Typical Applications: Electric furnaces, staged heating systems

 

Application and Compatibility:

This sequencer relay is used in electric heating systems to sequence the energizing and de-energizing of heating elements, reducing electrical load stress and improving system longevity. It is compatible with a variety of Lennox electric furnace models and other HVAC systems that specify Mars 33243 or equivalent sequencer relays.

Installation Tips:
• Match the replacement relay’s coil voltage (24V) and timing ranges to your system specifications.
• Turn off all power before servicing electric heat components.
• Verify terminal connections and orientation match the original part to avoid wiring errors.
• Consult the furnace’s wiring diagram or service manual during installation.

 

Benefits of Upgrading with Lennox 27P95:

• Enhances staging control of electric heat elements
• Improves reliability and reduces stress on heating components
• Extends the service life of the electric heating system