Honeywell M847D1012 Damper Actuator
List Price: $160.23 Sale Price: $112.50
Honeywell M847D1012 Damper Actuator. The M847D is a two position, 24 Vac spring return damper actuator designed to operate directly driven zone dampers, used to control air flow in ducts. The synchronous motor actuator can be driven open (or closed) using any 24 volt rated two position switch - eg. a wall switch or a thermostat
subbase switch. It is designed to operate ARD, EARD and ZD zone dampers.
• Low voltage, spring-return damper actuator.
• Equipped with anti-rotation and drive shaft extensions for direct mounting to 7/16 inch diameter coupling style dampers.
• Adjustable range stops.
• Direct replacement for M847D1004
A great product that is easy to install and will last a long time. by William B. Krantz (Boulder Co US)
Indeed this part is very easy to install. In order to install this part, it is advisable to turn off the power to your heating system. However, this can cause a problem with the system functioning properly when this part is initially installed. Depending on the control system for your forced air heating system, you might find that this activator will not open the louver in plenum right away. The reason for this is that some control systems require the system to go through a complete cycle before they return to normal operation. Just leave the system go through its cycle - it will be functioning properly within a few hours. Note that installing this part saved me over $200 relative to having a furnace service company install the part for me. One recommendation - put a small amount of lubricating oil or light silicone grease on the teeth of the large gear on this part - it will greatly increase how long the part will last!
Furnace damper by Christine Davis (Brighton MI US)
The damper in the heating duct that provides zone heating for the downstairs was not opening properly although trying. Closer inspection indicated a problem with the motor. I ordered the new motor from Honeywell which promptly arrived in a couple of days and installed it. Everything is working as designed and just in time for cold weather. The part being an exact replacement for the old one made the job easy (20 minutes).