Carrier HH18HV140 Limit Switch, 110-140 Degree, Automatic Reset

Description

The Carrier HH18HV140 is an automatic reset limit switch engineered to protect furnaces and heating systems from unsafe high-temperature conditions. Designed as a genuine Carrier OEM replacement part, this limit switch monitors heat exchanger temperatures and automatically interrupts the burner circuit when temperatures exceed the rated threshold — then resets itself once safe operating conditions are restored.

Key Features

• Automatic reset operation — no manual intervention required after the temperature returns to a safe level
• Temperature range: 110–140°F, providing precise high-limit protection for residential and light commercial furnace applications
• Genuine Carrier OEM replacement part for reliable, like-for-like performance
• Interrupts burner operation upon high-temperature detection, preventing heat exchanger damage and potential fire hazards
• Direct drop-in replacement designed to restore original equipment performance

Application

The HH18HV140 limit switch is a critical safety component used in Carrier furnaces and air handlers. It is mounted on or near the heat exchanger and continuously monitors operating temperatures. When temperatures rise above the set point, the switch opens the control circuit to shut down the burner, protecting the system and occupants. The automatic reset function allows the switch to close again once temperatures fall back within the safe operating range, minimizing downtime and service calls.

Specifications

• SKU: HH18HV140
• Brand: Carrier
• Type: High-Limit Switch
• Reset Type: Automatic
• Temperature Range: 110–140°F
• Application: Furnaces and air handlers