Honeywell Home MSTN/U Motor Switch Terminal - 24 V AC, 6 VA

The MSTN is a motor switch terminal from Honeywell Home, 24 V AC, 6 VA.

It is the end switch half of a zone valve: the contact that tells the panel the valve has finished opening. A panel that starts the circulator on the call rather than on the end switch runs the pump against a valve that has not moved yet.

This is a service part. The valve body and the motor stay where they are, so the repair is a terminal change rather than cutting a valve out of the pipe.

A zone that heats but never lets the boiler fire, or one where the circulator runs before the valve has opened, is usually this contact rather than the valve.

• Brand: Honeywell Home
• Manufacturer Part #: MSTN/U
• Type: Motor switch terminal
• Rating: 24 V AC, 6 VA
• UPC: 085267260138
• Category: Replacement Actuators