Description
The Honeywell 278Y07 circulating control aquastat (part of the L4006 series) is an immersion‑type controller designed to regulate and limit liquid temperatures in closed systems, especially hydronic boilers, circulators, tanks, or storage units. With a built‑in SPST switch, adjustable temperature set points, and rugged construction, this controller helps protect equipment, maintain energy efficiency, and ensure safe and reliable operation.
Features:
- Totally enclosed Micro Switch snap-acting switches operate on temperature rise to setpoint.
- Visible control point scale and external adjustment screw permit easy setting.
- Horizontal or vertical insertion of the sensing element.
- Direct or well immersion of the sensing element.
- Models available for strap-on mounting.
- Remote bulb model may be used to sense air temperature in ducts and in outside air sensing applications.
- Select models include heat-conductive compound.
- Select models have wells.
- UL limit rated device.











