Lennox 10U66 (103735-04) is an OEM high pressure switch designed to protect HVAC and refrigeration systems from excessive discharge pressure. This safety control actuates at 640 PSI and features a manual reset, ensuring the system cannot restart until the underlying high pressure condition is corrected. It is commonly used in commercial and residential HVAC applications where reliable pressure monitoring is critical to compressor protection and overall system safety.

Manufactured to original equipment specifications by Lennox, this high pressure switch provides dependable performance, accurate actuation, and long service life when installed as a direct replacement for the original part.

 

Key features and benefits:

• OEM Lennox replacement part
• Actuates at 640 PSI for high pressure protection
• Manual reset design prevents automatic restart after a fault
• Helps protect compressors and refrigeration components from damage
• Built for long-term reliability in demanding HVAC environments

 

Typical applications:

• Air conditioning and heat pump systems
• Commercial and residential refrigeration equipment
• Systems requiring manual reset high pressure safety controls

 

Part details:

• Lennox part number: 10U66
• Manufacturer number: 103735-04
• Switch type: High pressure
• Reset type: Manual
• Actuation pressure: 640 PSI

This Lennox 10U66 high pressure switch is ideal for technicians and contractors who require an exact OEM replacement to maintain system safety, code compliance, and reliable operation.