Overview
The Honeywell L4029E1029 is a manual reset duct limit control firestat engineered for safety-critical HVAC applications. This manual reset device opens a line or low voltage circuit if the air temperature reaches a critical level and can be used as a fire stat in the ductwork of air conditioning and ventilating systems. If the circulated air reaches a temperature indicative of fire, the limit control shuts off the fan, preventing the fan from contributing to the spread of fire. These controls are also suitable for use with any warm air furnace to provide positive lockout of the burner in the event of fan failure.
Key Features
- Fixed temperature limit of 200 degrees F with normally closed SPST switch type
- 200 F high limit stop with manual reset and 3-inch element insertion length
- Internal snap-acting switch actuated by a bimetal strip inserted directly into the air stream responds rapidly to temperature changes
- May be used as a fire stat in ductwork with positive lockout of burner in case of fan failure
- When temperature falls approximately 25 degrees below the cutout point, the switch may be reset by pushing the button and releasing
Technical Specifications
- Dimensions: 7.4″ x 4.5″ x 2.7″
- Weight: 0.76 lb
- Contact rating: 5 F.L. Amp 240 Vac
- Application: Fire safety and general purpose with duct mounting
- Fixed cutout point setting: 200°F
- Element insertion length: 3 inches
Typical Applications
In ventilating or air-conditioning installations, the safety control is normally installed with element just upstream of fan, or in downflow furnace installations located between filter(s) and blower where air circulation is not restricted. This duct-mounted firestat is essential for preventing fan operation during fire conditions and provides burner lockout protection in warm-air furnace systems.
Compatibility & Replacements
Compatible With
- Warm-air furnace systems with line or low-voltage control circuits
- Standard 240 VAC HVAC control networks
- Ductwork-mounted fire safety systems in air handling units
- Fan and burner control circuits in heating systems
Replaces / Drop-In Replacement For
- Reznor RPBL 42782 firestat (functionally equivalent manual reset 200°F firestat)
- Other manual reset 200°F duct limit controls with 3-inch insertion element
Works With
- Standard HVAC control systems requiring fire safety shutdown
- Line-voltage and low-voltage control circuits (SPST switch compatible)
- Warm-air furnace fan and burner safety circuits
- Ventilation and air-conditioning ductwork installations




