Resideo - Honeywell Home L4008B1013 Remote Bulb Aquastat Controller

Remote Bulb Aquastat Controller, part of the Resideo Honeywell Home line with model L4008B1013, delivers reliable boiler control for residential heating and storage-tank systems. This precision controller features a 3/8 inch diameter x 2-7/8 inch long copper sensing bulb with a 66 inch capillary for flexible installation in either horizontal or vertical immersion. It supports a temperature range from 100 to 240°F with a sensor rated for a maximum of 150°F for safety and longevity.

Designed for robust boiler control and storage tank applications, it offers a SPST contact configuration with break on temperature rise and a 3/4 inch conduit connection with screw terminals for easy wiring. The unit is UL and CSA approved, ensuring compliance and reliability. The adjustable differential (5–30°F) lets you dial in precise cut-in and cut-out temperatures. Sensing options include the capillary bulb filled with toluene or silicone oil, and it supports varied pressure ratings (200 psi capillary, 255 psi immersion well).

• Precise sensing: 3/8 in diameter x 2-7/8 in copper bulb with 66 in capillary for flexible installation (horizontal or vertical).
• Wide temperature range: 100–240°F operating range; sensor rated to 150°F maximum.
• Reliable contacts: SPST configuration; Break on temperature rise.
• Rugged wiring: 3/4 in conduit connection with screw terminals; suitable for boiler and storage tank setups.
• Certified safety: UL and CSA approved.
• Adjustable differential: 5–30°F to tune cut-in/cut-out.
• Pressure and sensing: 200 psi capillary and 255 psi immersion well; sensing liquid: toluene or silicone oil.