I have a new Trane t900cont thermostat (3 wire). How do I wire it to an exsiting 5 wire that comes out of the current socket? My ac usint is a Trane XR15 with Trane AHU 4TEE MODEL

If the thermostat has only 3 connections, it requires the matching equipment interface module.

What is the name and model of the interface equipment? Thanks

All sorted out here

Trane T-stat: 900 will not work with XL15i??? - Heating & Air Conditioning Forum - GardenWeb (http://ths.gardenweb.com/forums/load/hvac/msg081951396095.html)

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