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Replace TrolAtemp Thermalstat

Dear: HVAC experts.
I have a two zones Pause 2 By Lenox Model G21Q4/5-100-5 furnace connected to a TrolATemp Mastertrol MINI - Zone Model MM -2 controller with three TrolATemp Damper model number 93-057h-001/00/c4-90 (2 for the main floor, 1 for basement), and two TrolATemp - Chronotherm III by Honeywell configured as a master and slave.

I would like to replace the old Chronotherm III thermalstats with Nest 3rd generation thermostats. I understand that I need to replace TrolAtemp Master Controller and re-wire the cables. Is there any HVAC emperts out there can help tell me what master controller I need to buy and how to re-wire my current wires to have the furnace to work with Nest 3rd gen thermastat and Do I need to replace the TrolATemp Dammper? Current wires configuration provided with attached jpeg file.

Thank you,
N. Pham


  • John Mills_5
    John Mills_5 Member Posts: 952
    Personally I'd go with a Honeywell 432 board. It handles 2 stage of heat so when you get rid of that Pulse, you can get a 2 stage furnace for better control of the heat.

    Make sure you hook up a common from the zone panel to the thermostats. Works a lot better that way.
  • ratio
    ratio Member Posts: 3,649
    Read this thread and this one as well.