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Convert a TrolATemp 2 Zone System to 1 Zone

shiprecshiprec Member Posts: 3
Is it possible to convert a two zone TrolATemp to one zone?

I have a house that was built in the late 90's, and the furnace was upgraded 3 years ago. However, when they upgraded the furnace, they didn't swap out the old TrolATemp system. It is in a Master/Slave configuration with two thermostats connected to an MM-2. Since the basement thermostat is rarely changed, I wanted to replace that thermostat with a Nest temperature sensor and just control to that the 5 days of the year I would use it.

So my question is, can I remove a zone, thereby remove the MM-2, or should I just buy another Nest thermostat for the basement and upgrade to an HZ311?

Master Thermostat

Slave Thermostat

MM-2 Wiring



  • HVACNUTHVACNUT Member Posts: 3,274
    I'm lost. You want to make the furnace one zone but you want to install a Nest in the basement to only provide heat to the basement 5 days a year? If you want to have the basement operate independently, then it needs to be zoned.
    Does the furnace have an ECM motor? Is there a barometric relief bypass? I would replace the zone board with an HZ311 and the thermostats (Honeywell T6 WiFi). I wouldn't use Nest but that's just me.
  • shiprecshiprec Member Posts: 3
    Thanks for the response, and sorry if I wasn't clear. I wanted to install a Nest at the master thermostat, and one of the little hockey puck temperature sensors in place of the one in the basement.

    The Ruud system is a variable speed, and I've only been in the house for three weeks and haven't spotted any barometric bypass dampers.
  • shiprecshiprec Member Posts: 3
    I was looking at the wiring for the HZ311 last night and think I am understanding it pretty well. Just wanted to confirm that the orange and black wires from the master thermostat are no longer needed with the new zone control board?
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