Can Mysa Smart Thermostat replace a Fujitsu wired controller with R, W, and B terminals?

Some Fujitsu systems use a wired controller with terminals such as R, W, and B, but still communicate using a proprietary Fujitsu control protocol. Mysa Smart Thermostat cannot be wired directly to those proprietary communication terminals.

What is needed

To use a standard 24V smart thermostat with this type of Fujitsu system, the system must first be converted to standard 24V thermostat signals by compatible Fujitsu hardware. In many cases this means:

• A Fujitsu thermostat converter, such as UTY-TTRX or the updated UTY-TTRXZ1, to translate standard thermostat calls into Fujitsu communication.

• A separate 24V isolation transformer, because the converter does not provide thermostat power on its own.

Important installation guidance

• Do not connect Mysa Smart Thermostat directly to proprietary Fujitsu communication terminals.

• Confirm the exact Fujitsu indoor unit and converter compatibility before purchasing or installing parts.

• Have a qualified HVAC professional install the converter, transformer, and thermostat wiring.

• The Mysa Power C-Wire Adapter is not a substitute for a manufacturer thermostat converter.

If the Fujitsu system is controlled by an infrared handheld remote instead of a wired proprietary controller, Mysa for Mini-Splits may be the better product to review.