Interface Module GENERAL AIRSTAGE UTY-TWBXF1 | Montreal, Laval, Longueuil, South Shore & North Shore

With their refined look, the ASU RLS2 and RLS3 (GENERAL or Fujitsu) designer wall-mounted heat pumps are popular. As they leave the factory, an infrared remote runs them. As soon as you want to add a wired wall controller, a dry contact kit or a wired Wi-Fi module, an interface board becomes necessary: the GENERAL AIRSTAGE UTY-TWBXF1 kit. Only its GENERAL name sets it apart from the Fujitsu AIRSTAGE UTY-TWBXF1 (the same part under the Fujitsu AIRSTAGE brand). The reason is that Fujitsu General Limited, now owned by Paloma Rheem Holdings, changed its corporate name on January 1, 2026 to become GENERAL Inc., without touching its factories, its AIRSTAGE products or its model numbers. While the Fujitsu brand gradually makes room for GENERAL, AirGreen, an authorized GENERAL and Fujitsu AIRSTAGE dealer, sells the kit under both names.

The board that opens the way to wired controls

In practical terms, it is an interface board, housed in the unit, that bridges the unit and the wired controls. Six models are covered: ASU9RLS2, ASU12RLS2, ASU15RLS2, ASU9RLS3, ASU12RLS3 and ASU15RLS3. It makes the following connections possible:

1. two wired wall controllers, the UTY-RSNUM and the UTY-RNNUM;
2. the UTY-XWZXZ5 dry contact wire kit: a building management system, a timer, a presence detector or a card switch can then communicate with the unit;
3. and, on some units, the FJ-RC-WIFI wired Wi-Fi modules, which absolutely need this board.

Watch out for one detail: connected through this kit, the UTY-RNNUM controller no longer uses its internal temperature sensor, which is disabled; the reading falls to the indoor unit. This point weighs in our choice of controller and of its location.

Technical specifications

• Type: interface kit (board) for wired controls
• Compatible systems: GENERAL or Fujitsu designer wall-mounted units ASU9RLS2, ASU12RLS2, ASU15RLS2, ASU9RLS3, ASU12RLS3, ASU15RLS3
• Permitted controllers: UTY-RNNUM, UTY-RSNUM
• Other permitted accessories: UTY-XWZXZ5 dry contact kit; FJ-RC-WIFI wired Wi-Fi modules (required on some units)
• Special feature: UTY-RNNUM internal sensor disabled with this kit
• Display: none
• Connectivity: interface board between the indoor unit and wired controls

The advantages of a wired control

The infrared remote has its flaws: it goes missing, its batteries eventually give out and it has to be aimed at the unit. The wired controller keeps its place on the wall and can be read at a glance, which makes a real difference in a child's bedroom, a rental unit or an office. On the dry contact side, we are talking integration: a management system, a presence detector or a timer that starts and stops the unit, the card switch of a hotel room. The wired Wi-Fi module, finally, puts the unit at your phone's fingertips, handy for getting the heat going at the cottage before you arrive in the middle of winter.

All of these options go through the UTY-TWBXF1 first when the unit is a designer wall model. The board itself controls nothing on its own; everything depends on the accessory paired with it. Other unit families use other kits from the manufacturer, for example the UTY-XCBXZ2 or the UTY-TWRXZ2; the exact model of your equipment tells you which one to take.

Which controller to pair with it

For a discreet wall control without programming, the UTY-RSNUM does the job very well: slim housing, backlit screen, error codes, filter reminder and five operating modes. The UTY-RNNUM, the second option accepted, loses the use of its internal sensor in this setup, and the unit reads the temperature. You mainly want to run the unit from your phone: then it is an FJ-RC-WIFI wired Wi-Fi module that gets paired with the kit. Tell us what the room is used for, and our advisors will steer you toward the right combination.

Installing the kit

This work is done inside the equipment itself: the indoor unit has to be opened to connect the board. With the power off, our technicians put the UTY-TWBXF1 in place, connect the chosen controller or accessory to it and route the wiring to the planned spot. The unit is then powered back up, and every function is tested. Rather than selling the board alone, we prefer to supply the kit with its accessory, so that compatibility is settled in advance.

Maintenance

Housed inside the unit, the board is safe from dust as well as handling, and it needs no maintenance. Changing controllers later does not require removing it. That does not exempt the wall unit from its usual care: clean filters and, every year, an inspection of the coil and the drain.

Why AirGreen

AirGreen Inc. grew up as a family business, over more than 15 years of air conditioning and heating; it holds an RBQ licence and has a storefront in Boucherville, with its showroom. That track record has taught it the connection specifics of the manufacturer's units, whether they carry the GENERAL or the Fujitsu brand. The GENERAL AIRSTAGE UTY-TWBXF1 interface kit, paired with the controller or accessory of your choice, is sold and installed by AirGreen, in Montreal, Laval, Longueuil, the North Shore as well as the South Shore.