Letter:
ST-002-2017
Date:
April 6, 2017
To:
All Unitary Products Branch Service, Sales, and Training Managers
All Unitary Products Distribution Service, Sales, and Training Managers
S1-THXU280 (B, W) Thermostat software update for
Subject:
Variable Capacity air conditioner or heat pump
Product:
S1-THXU280,
Thermostat
This is an update to service tips letter ST-012-16 released on October 31, 2016.
The S1-THXU280 Hx
required a software update to work with communicating equipment. The software update
had to be manually pushed to the thermostat by the technical services group.
With the introduction of the Variable Capacity air conditioner and heat pump models the
thermostats must have a software update to control these new models. The update will
be done automatically if the thermostat has a WiFi internet connection.
To use this thermostat in communicating mode install it at the customers location and
wire the thermostat using A+, R, C, B- connections from the thermostat to communicating
equipment. If using this thermostat with communicating equipment other than the new
Variable Capacity air conditioner or heat pump, you must set all indoor and outdoor
equipment jumpers. If using the thermostat with Variable Capacity outdoor equipment,
the outdoor equipment will control airflow during heat pump heating or cooling. You must
set the HEAT jumper on the indoor equipment regardless if you are using a TM*V gas
furnace or an air handler with field installed electric heat. Once all equipment jumpers
are properly set, apply power to the system and perform thermostat setup. The S1-
THXU280 thermostat does not contain communicating software therefore it will not
recognize the indoor equipment automatically. Set the thermostat up for conventional
equipment operation even though it is not wired for conventional control. The next step
will require connecting the thermostat to the WiFi internet connection at the installed
location.
Instructions on connecting the thermostat to WiFi are located in the
homeowner's quick reference guide shipped with each thermostat. If the thermostat is
connected to the internet the WiFi status indicator will be green in color. See the image
below for an example.
S1-THXU280B,
TM
Touch-screen Thermostat released in May of 2016 previously
Unitary Products
Technical Services
Service Tips Letter
S1-THXU280W
Hx
TM
Touch-screen