Resideo - Honeywell Home L4081B1096 Aquastat Controller

The L4081B1096 Aquastat Controller is a versatile Aquastat Controller designed for gas/oil fired hydronic heating systems. This horizontal immersion unit combines multiple controls, high-limit protection, and a circulator interface for dependable boiler operation.

With a broad temperature range, the high limit covers 130 to 240 °F while the low limit ranges 110 to 220 °F. The 150 °F switch rating and 265 °F sensing element rating ensure robust performance, while SPST contact configuration supports straightforward wiring across diverse loads (8 A at 120 V AC / 5.1 A at 240 V AC full load; 48 A at 120 V AC / 30.6 A at 240 V AC locked rotor; plus 0.25 A at 0.25–12 V DC (millivolt), 360 VA transformer load).

Designed for horizontal immersion, the controller features 1/2 inch conduit connections, UL and CSA approvals, and a compact footprint (4-1/8 in W x 2-3/4 in D x 3-7/8 in H). A fixed 10 °F differential provides stable differential control, while pressure ratings of 200 PSI (well-mounted) and 100 PSI (direct immersion) support demanding systems. Insulation depth is 3 inches with a 7/8 inch knockout and humidity tolerance up to 95% RH non-condensing.

• Application: Gas/oil fired hydronic heating system
• Temperature control: High limit 130–240 °F; Low limit 110–220 °F; differential 10 °F (fixed)
• Electrical & wiring: SPST contact; 8 A/120 V, 5.1 A/240 V full load; 48 A/120 V, 30.6 A/240 V locked rotor; 0.25 A at 0.25–12 V DC (millivolt)
• Certifications: UL and CSA approved
• Physical specs: 4-1/8" W x 2-3/4" D x 3-7/8" H; 1/2" conduit; 3" insulation; 7/8" knockout; 0–95% RH