Honeywell l4006e1117/u High Limit Aquastat 100-240F Npt

Product Description

The HONEYWELL l4006e1117/u is a high limit aquastat controller designed for immersion-style liquid temperature sensing in hydronic heating systems. It monitors water temperature and opens the circuit when the setpoint is exceeded, protecting boilers and storage tanks from overtemperature conditions. The control operates across a range of 100 to 240 degrees F and connects via a 3/4 inch NPT fitting. A manual reset mechanism requires a deliberate operator action before the system can restart after a high limit event, adding a layer of fault accountability. Licensed HVAC and plumbing technicians are the primary installers of this control.

This aquastat is suited for residential and light commercial hydronic heating applications, including hot water boilers and storage tanks where liquid temperature limiting is required. It is an immersion-type device, meaning the sensing element is inserted directly into the fluid through an existing well or tapped port in the boiler or tank. The manual reset feature makes it appropriate for high limit duty where automatic restart after a fault is not acceptable by design or by code.

Key Features

• Temperature range of 100 to 240 degrees F covers typical hot water heating system operating limits
• 3/4 inch NPT connection suits standard boiler tappings and immersion wells
• Manual reset operation prevents automatic restart after a high limit trip
• Immersion-type sensing element for direct liquid temperature measurement
• Suitable for boilers, storage tanks, and other liquid temperature control applications

Compatibility

Designed as an OEM-style replacement or new-installation high limit aquastat for residential and light commercial hot water boilers and storage tanks equipped with a 3/4 inch NPT immersion well or tapping.

Installation Notes

Installation should be performed by a licensed HVAC technician or plumber in accordance with local mechanical codes and the boiler manufacturer's instructions. Shut down and de-energize the boiler and allow system water to cool before removing or installing the aquastat. The sensing element must be fully seated in the immersion well to ensure accurate temperature response. Verify control wiring connections comply with applicable NEC low-voltage control circuit requirements before restoring power.