1. Introduction
The Fantini Cosmi CH121 is an electronic microprocessor programmable thermostat designed for precise control of heating and air conditioning systems. This device features weekly programming capabilities and operates efficiently using two AAA 1.5V alkaline batteries, eliminating the need for direct electrical line connections. This manual provides essential information for the proper installation, operation, and maintenance of your CH121 thermostat.
Image 1.1: Fantini Cosmi CH121 thermostat in its retail packaging. The packaging displays the model numbers CH121 and CH123, along with images of the thermostat in different finishes.
2. Product Features
- Microprocessor Control: Electronic microprocessor for accurate temperature management in heating and air conditioning systems.
- Battery Powered: Operates on 2 AAA 1.5V alkaline batteries, ensuring independence from the main electrical line.
- Backlit LCD Display: Features a graphic LCD screen with mixed blue LED backlight, offering adjustable backlight duration for clear visibility.
- User Interface: Equipped with 4 function keys: On/Off, Comfort (for temperature adjustment), and Economy.
- Temperature Display Options: Allows selection of temperature display in Celsius (°C) or Fahrenheit (°F).
- Adjustable Differential: Provides an adjustable temperature differential for customized comfort.
- Contact Rating: 5 (3) A 250 VCA, with a voltage-free switching contact.
- Protection Index: IP20.
- Compliance: Conforms to EN 60730 – 2-9 standards.
- Compatibility: Designed to be compatible with most common civil series plates, including Bticino, Vimar, Gewiss, and Legrand.
Image 2.1: Front view of the Fantini Cosmi CH121 thermostat, showcasing its backlit LCD display and four control buttons. The display shows a temperature reading of 21.0 degrees.
3. Package Contents
The Fantini Cosmi CH121 package includes the following components:
- 1x CH121 Thermostat Unit
- 3x Colored Covers (White, Silver, Anthracite)
- 3x Special Cases for Bticino Axolute and Ave System 44 (White, Silver, Anthracite)
- 3x Pairs of Colored Adapters (White, Silver, Anthracite)
- 1x Pair of Adapters for Bticino Matix (White)
- 2x Frames for compatibility with various common plates
Image 3.1: A collection of interchangeable frames and covers included with the Fantini Cosmi CH121 thermostat, available in black, silver, and white to match different interior designs.
Image 3.2: Various mounting frames provided with the Fantini Cosmi CH121 thermostat, designed to ensure compatibility with a wide range of electrical plate systems.
4. Setup and Installation
The CH121 thermostat is designed for built-in installation. Follow these general guidelines for proper setup:
- Power Off: Before beginning any installation, ensure that the main power supply to the heating/cooling system is turned off at the circuit breaker to prevent electrical shock.
- Mounting Location: Select an appropriate location on a wall, away from direct sunlight, drafts, or heat sources that could affect temperature readings.
- Wiring: Connect the thermostat to your heating/cooling system according to the wiring diagram provided in the full product manual. The CH121 uses voltage-free switching contacts. Refer to the terminals labeled 1, 2, and 4 on the back of the unit.
- Battery Installation: Insert 2 AAA 1.5V alkaline batteries into the designated battery compartment. Ensure correct polarity.
- Plate Compatibility: Utilize the provided frames and adapters to ensure seamless integration with your existing electrical plates. The CH121 is compatible with popular plate series such as Bticino Living Code, Light, Axolute, Matix; Vimar IDEA, Rondò, Plana, Eikon; Gewiss Chorus One, Lux, Art; Ave System 45, Banquise, Black, White, Yes, System 44 Zama, Personal; and Legrand Cross, Voile, Quadra, Vela Tonda.
- Secure Mounting: Once wired and batteries are installed, securely mount the thermostat into the wall box using the appropriate frame and cover.
- Power On: Restore power to the system at the circuit breaker.
Image 4.1: Rear view of the Fantini Cosmi CH121 thermostat, showing the wiring terminals (labeled 1, 2, 4) and specifications such as 5(3)A 250V~ T45, indicating its electrical rating and temperature class.
5. Operating Instructions
The CH121 thermostat features a user-friendly interface with four main function keys:
- On/Off Button: Toggles the thermostat power on or off.
- Comfort Button: Used to adjust the desired temperature up or down. Pressing this button typically activates the backlight first, then subsequent presses adjust the setting.
- Economy Buttons: These buttons are used to set or activate economy modes, which typically maintain a lower temperature to save energy.
General Operation:
- Activating the Display: When the display is off (but the thermostat is active), the first press of any button will typically only activate the backlight. Subsequent presses will then perform the button's function.
- Setting Temperature: Use the Comfort buttons to increase or decrease the target temperature. The display will show the set temperature temporarily.
- Weekly Programming: Refer to the detailed programming section in the complete manual for instructions on setting weekly schedules for heating and cooling. This allows for automated temperature adjustments throughout the week.
- Temperature Unit Selection: The thermostat allows you to switch between Celsius (°C) and Fahrenheit (°F) display modes. Consult the full manual for the specific key combination or menu option to change this setting.
- Backlight Duration: The duration for which the backlight remains active can be adjusted. Refer to the full manual for instructions on customizing this setting.
6. Maintenance
To ensure optimal performance and longevity of your Fantini Cosmi CH121 thermostat, follow these maintenance guidelines:
- Battery Replacement: The thermostat is powered by 2 AAA 1.5V alkaline batteries. Replace them when the low battery indicator appears on the display. Always use new, high-quality alkaline batteries.
- Cleaning: Clean the thermostat's exterior with a soft, dry cloth. Do not use abrasive cleaners, solvents, or chemical sprays, as these can damage the display or casing.
- Avoid Obstructions: Ensure that the thermostat is not obstructed by furniture, curtains, or other objects that could interfere with accurate temperature sensing.
- Environmental Conditions: The maximum ambient temperature for operation is 45 °C. Avoid exposing the thermostat to extreme temperatures or humidity.
7. Troubleshooting
If you encounter issues with your CH121 thermostat, consider the following common solutions:
- No Display/Thermostat Not Responding: Check if the batteries are correctly installed and have sufficient charge. Replace batteries if necessary.
- Inaccurate Temperature Reading: Ensure the thermostat is not exposed to direct sunlight, drafts, or heat sources. Verify that the air vents on the unit are not blocked.
- Heating/Cooling System Not Activating: Check the thermostat's mode (heating/cooling) and set temperature. Ensure the system's circuit breaker is on. Verify wiring connections.
- Display Illegibility: While the display is backlit, some users have reported challenges with readability under certain conditions. Ensure adequate ambient lighting.
- Battery Indicator Always On (with rechargeable batteries): Rechargeable batteries often have a slightly lower voltage (e.g., 1.2V) compared to alkaline batteries (1.5V). This lower voltage may cause the low battery indicator to remain active even when the batteries are fully charged. This is a characteristic behavior and does not necessarily indicate a fault.
For more detailed troubleshooting or complex issues, please refer to the comprehensive manual available on the manufacturer's website or contact Fantini Cosmi customer support.
8. Specifications
| Specification | Detail |
|---|---|
| Brand | Fantini Cosmi |
| Model Number | CH121 |
| Power Supply | 2 x AAA 1.5V Alkaline Batteries |
| Contact Rating | 5 (3) A 250 VCA |
| Voltage | 15 Volts (internal circuit) |
| Protection Index | IP20 |
| Max Ambient Temperature | 45 °C |
| Product Dimensions (L x W x H) | 5.2 x 5.8 x 6.8 cm |
| Item Weight | 180 grams |
| Color | Multicolor (with interchangeable covers) |
| Compliance | EN 60730 – 2-9 |
Image 8.1: The Fantini Cosmi CH121 thermostat held in a hand, illustrating its compact size with approximate dimensions of 2.7 inches (6 cm) in height.
9. Warranty and Support
For information regarding warranty coverage, technical support, or to download the complete product manual, please visit the official Fantini Cosmi website. The manufacturer's website often provides comprehensive documentation and contact details for customer assistance.
You can find more information on the official product page: Fantini Cosmi IntelliComfort Thermostat
