Resideo - Honeywell Home L8100B1128 Aquastat Controller

The L8100B1128 Aquastat Controller from Resideo - Honeywell Home delivers dependable temperature control for water heaters and hydronic systems. This high-limit aquastat features a 3/8 inch diameter bulb and a 39 inch capillary, with well immersion for accurate sensing and reliable performance in mixed heating environments.

With UL, CSA, and AGA approvals, it provides safe operation and easy integration. The SPST contact configuration is rated 2 A at 24 VAC (millivolt), and it breaks on temperature rise to prevent overheating. The unit supports a fixed differential: 5°F for the controller and 20°F for the energy cut-off switch.

Designed for water heaters and hydronic systems, it includes 3/4 inch conduit connection, an internal adjustment screw, insulation depth of 1-1/2 inches, and an overall footprint of 2" W x 2-1/8" D x 5-5/8" H.

• Temperature range: 100–180°F operating, with high limit up to 210°F
• Sensor and durability: 3/8" diameter bulb, 39" capillary, well immersion
• Electrical: SPST contact, 2 A at 24 VAC; breaks on temperature rise
• Energy cutoff: 200°F rating; fixed differential 5°F (controller) and 20°F (energy cut-off switch)
• Connections: 3/4" conduit; internal adjustment screw
• Applications: suitable for water heaters and hydronic systems
• Approvals: UL, CSA, AGA
• Dimensions & insulation: 2" W x 2-1/8" D x 5-5/8" H; insulation depth 1-1/2"