The ABB Caldion® CAR/U4.2.1.1 is a flush-mounted fan-coil room temperature controller with 0–10 V valve outputs. It supports 2-pipe, 2-pipe + electric heater, and 4-pipe systems — standalone or as a KNX device with integrated bus coupler.

Built-in temperature sensor, 2 binary inputs, 3 fan speeds, capacitive touch, and a large frameless display. Choose white or black glass finish below.

Key Features

• 0–10 V valve control: Analogue actuator outputs for modulating FCU valves (this U4.2 series).
• 2 / 2+EH / 4-pipe: One device covers common fan-coil hydraulic layouts.
• Standalone or KNX: Integrated bus coupling for retrofit or networked installs.
• 3 fan speeds + RTC UI: Capacitive touch and large frameless display.
• 2 binary inputs: Window contact, dewpoint, or condensate alarm.
• On/Off sister: For relay valves see CAR/U4.1.1.1.

At a Glance

Specification	Detail
Product type	KNX / standalone fan-coil RTC, 0–10 V valves
Order family	CAR/U4.2.1.1-xx
Valve output	0–10 V
Pipe systems	2-pipe · 2-pipe + EH · 4-pipe
Fan control	3 speeds
Binary inputs	2
Mounting	Flush-mounted, BS standard · 86 × 86 × 16 mm
Finishes	White (−84) · Black (−71)
Protection	IP20

Technical datasheet, product manual, installation instructions, ETS .knxprod (0–10 V), CAD, and CE declaration are under Downloads.

Color / Order Codes

Finish	Order code	Product ID
White	CAR/U4.2.1.1-84	2TAZ741010R0001
Black	CAR/U4.2.1.1-71	2TAZ741010R2001

Applications

• Modulating FCU valves: 0–10 V control for finer comfort and energy use.
• 2- and 4-pipe rooms: Heating/cooling with local fan stages.
• KNX room automation: Network via integrated BCU or start standalone.
• On/Off valves: Prefer CAR/U4.1.1.1.

Installation Notes

Flush-mount in a BS standard box (86 × 86 mm face). Wire 0–10 V valves, fan stages, binary inputs, and optional KNX. Commission standalone via local UI or import the CAR/U4.2.1.1 0–10 V .knxprod from Downloads into ETS.