The Danfoss HSA3 3-Port Mid-Position Actuator (087N658700) is a genuine replacement motorised actuator designed to work with Danfoss 3-port mid-position valve bodies. It provides the motorised movement needed to shift the valve between heating, hot water, or mid-position settings based on control system signals.

Function & Purpose

This actuator receives electrical signals from room thermostats, cylinder thermostats, programmers, or heating control systems and uses them to move the linked 3-port valve to the correct position. In a mid-position valve setup, the actuator enables the valve to route hot water to the heating circuit, the hot water circuit, or both simultaneously when required. Replacing a worn or faulty actuator with the HSA3 restores smooth, reliable motorised control of the valve and precise water distribution in the heating system.

Compatibility

The HSA3 actuator is designed specifically for Danfoss 3-port mid-position valve bodies that accept the 087N658700 actuator. It interfaces with standard heating control signals and fits directly onto the matching valve body, making it suitable for use in central heating and hot water systems that use this type of motorised control valve.

Build Quality

Manufactured to Danfoss quality standards, the HSA3 actuator is built for durability and long service life. Its internal motor and gearing provide reliable, quiet operation over repeated cycles, and the casing is designed to withstand the typical environmental conditions found in boiler rooms and heating systems.

Ideal Applications

This actuator is ideal for heating engineers, service technicians, and installers performing maintenance, diagnosis, or replacements on Danfoss 3-port mid-position valves. It is particularly useful where valve movement is sluggish, unresponsive, noisy, or fails to reach the correct position due to actuator wear or failure, helping to restore dependable control of heating and hot water distribution.