Danfoss Zone Valve Actuator HPA2 2 Port 230V 087N6579

The Danfoss HPA2 is a two-port, normally closed motorised zone valve actuator with a spring return and an SPST auxiliary switch. It is part of the Danfoss H-Series actuator range and is designed to sit on a motorised zone valve body in heating and district energy systems. The head drives the valve open on a 230 V AC signal from a thermostat or programmer, and the spring return closes the valve when the signal is removed.

• The zone stays cold when the thermostat calls for heat, with no movement at the valve spindle.
• The actuator motor runs but the valve does not open or close, often a stripped drive or seized spindle.
• The zone stays hot when it should be off, indicating the normally closed valve is not seating.
• The auxiliary switch no longer makes or breaks the boiler or pump circuit.
• Buzzing, humming or a hot actuator head, which points to a failing motor or gear train.

• Confirm the valve body is a two-port normally closed type that accepts an HPA2 head.
• Check the supply is 230 V AC before fitting, as the actuator is voltage specific.
• Note the auxiliary switch type is SPST if the control circuit relies on it.
• Isolate the heating circuit electrically before removing the old actuator head.