Click here to Find a Contractor in your area.
Welcome! Here are the website rules, as well as some tips for using this forum.
Need to contact us? Visit

Replace TrolAtemp Thermalstat

npham605 Member Posts: 2
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: 935
    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: 2,763
    Read this thread and this one as well.
Sign In or Register to comment.


It looks like you're new here. If you want to get involved, click one of these buttons!