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Checks to perform before filling the system with water, including installation verification and pressure checks.
Procedure for flushing the system with water, removing air, and pressurizing it to 1 Bar.
Diagram and explanation for connecting the remote controller to the heat pump PCB terminals.
Details on connecting a master remote controller using shielded cable.
Wiring instructions for connecting a room thermostat to terminals #20, #21 using volt-free contacts.
Connecting a thermostat for heating/cooling mode control via terminals #24, #25.
Steps for accessing and configuring parameters in the installer level for initial setup.
Procedure to access the service level, enter password, and navigate parameters.
Methods to reset all parameters to default settings using specific button presses or power cycles.
Configuration details for System A, where the heat pump is controlled by a room thermostat for heating only.
Configuration for System B, controlling heating and domestic hot water via a room thermostat.
Configuration for System C, managing heating and cooling modes using a room thermostat.
Further parameters and settings for System C, covering humidity and mode control.
Configuration for System D, integrating heating, cooling, and DHW with room thermostat control.
Additional parameters for System D, including humidity and 3-way valve control.
How to record and monitor various sensor temperatures while the heat pump is running.
Using DIP switches for pump speed adjustment and understanding flow rate implications.
Procedures for resetting error codes via Auto, Power Off, or Manual methods.
The Chofu Commissioning Guide provides essential information for the installation, commissioning, and maintenance of Chofu heat pump systems, ensuring optimal performance and adherence to manufacturer's criteria. This document is designed to be read in conjunction with the Chofu Installation Manual and focuses on the setup of heat pump parameters and the integration of third-party controls.
The Chofu heat pump system is designed to provide efficient heating and cooling for residential and commercial applications. Its core function involves transferring thermal energy between the outdoor air and the indoor hydronic system, which can include underfloor heating, radiators, or fan coils. The system is managed by a dedicated heat pump controller, which allows for precise control over various operational parameters.
The heat pump controller acts as the central management unit for the entire system. It monitors and regulates flow temperatures, outdoor air temperatures, and, in systems with domestic hot water (DHW) functionality, DHW temperatures. The controller can be configured for different operational modes, including heating only, heating with DHW, heating and cooling, or heating and cooling with DHW. This flexibility allows the system to adapt to various climate conditions and user preferences.
Remote control capabilities are integrated through a room thermostat connection. This allows users to switch the heat pump on or off and, in more advanced setups, to change between heating and cooling modes. The thermostat interacts with the heat pump controller via volt-free contacts, ensuring safe and reliable operation. For thermostats with switched live outputs, an external relay is required to convert the signal to volt-free contacts, maintaining compatibility with the Chofu system.
The system also incorporates frost protection, which automatically activates when the room air temperature drops below a predefined threshold, preventing damage to the hydronic system in cold conditions. For cooling applications, the system can manage outgoing water temperatures based on either a fixed set point or a climatic curve, optimizing efficiency and comfort. Humidity compensation is also available for radiant cooling systems, preventing condensation by adjusting outgoing water temperatures based on room relative humidity.
Before initial operation, a pre-commissioning phase is crucial. This involves ensuring the heat pump is installed according to the manual, power is isolated, and the side cover is removed to access internal components. A key step is checking the pre-charge of the expansion vessel, which should be set to 1 bar.
Filling the system with water is a critical usage feature. The hydronic system must be thoroughly flushed using a flushing cart or mains pressure to remove air and debris. Once flushed, the system is pressurized to 1 bar. The heat pump includes a pump run switch on the terminal PCB, allowing manual operation of the circulation pump to facilitate complete venting of air from the system. Automatic air vents must be open during this process to ensure efficient air removal.
The heat pump controller is installed indoors in a dry location, such as a garage or service cupboard, as it is not rated for outdoor use. Connection to the heat pump's PCB involves low-voltage wiring for terminals #1 and #2, which are not polarity sensitive. It is explicitly stated that 230V should not be applied to these terminals to prevent damage.
Configuring the heat pump controller involves accessing different parameter levels: installer and service. For installer-level parameters, a specific button combination (Menu, Up, Down) held for 3 seconds grants access. Parameters are identified by 4-digit numbers, and their values can be adjusted using the Up/Down and +/- buttons. The Set button confirms changes, and another button combination returns the controller to the main menu.
The service level provides access to all parameters and requires a password ("738") to enter. This level is typically used by qualified technicians for advanced configurations. The procedure for setting parameters at the service level is similar to the installer level. To exit the service level, the Menu, Up, and Down buttons are held for 3 seconds, or the system automatically reverts to normal operation after 10 minutes of inactivity.
Room thermostat connection is a primary usage feature for controlling the heat pump. Thermostats connect to terminals #20 and #21 using volt-free contacts. Open contacts signify "Off," while closed contacts signify "On." For thermostats with heating and cooling changeover functionality, terminals #24 and #25 are used. Open contacts typically indicate heating mode, and closed contacts indicate cooling mode. Parameter 5120 and 5124 enable these remote contact functionalities.
The system supports various configurations, including heating-only systems with or without DHW, and heating and cooling systems with or without DHW. Each configuration requires specific parameter adjustments, such as flow temperature set points for heating (e.g., 35-45°C for underfloor, 60°C for radiators), DHW set temperatures, and maximum outgoing water temperatures.
Regular operational checks are crucial for maintaining the system's performance. After setup, it is recommended to verify that the heat pump starts and stops as expected in response to the controls and that there is adequate flow rate at manifolds, leading to hot radiators.
Monitoring sensor values is a key maintenance feature. The heat pump controller allows users to view various operational temperatures, including return water temperature (01 00), flow water temperature (01 09), outdoor air temperature (01 06), and DHW sensor temperature (01 31). These values can also be viewed directly from the outdoor unit's terminal PCB by turning on dip switch SW4. The Pump SW button on the PCB allows cycling through different monitor numbers.
The system also provides additional settings for optimizing water pump speed. If an excessive flow rate occurs due to low pressure loss in the circulating loop, the main water pump speed can be adjusted. The PCB (Terminal) features dip switches (SW5 and SW6) that allow selection of three pump speeds: Level 3 (Maximum), Level 2 (Medium), and Level 1 (Minimum). At factory shipment, SW5 and SW6 are off, setting the pump to maximum speed. It is important to note that excessively low flow rates can lead to diminished capacity, poor circulation, or system errors.
Error resetting is an important maintenance feature. The system provides different methods for resetting errors, depending on the error code. These methods include:
The Chofu installation manual contains a comprehensive "List of Errors codes" that details the specific reset procedure for each error. If errors persist after attempting these reset procedures, users are advised to contact the technical aftersales team for assistance. This structured approach to error handling ensures that issues can be diagnosed and resolved efficiently, minimizing downtime and maintaining system reliability.
General| Heating Capacity | Unknown |
|---|---|
| Cooling Capacity | Unknown |
| Power Supply | Unknown |
| Refrigerant | Unknown |
| Operating Temperature (Heating) | Unknown |
| Operating Temperature (Cooling) | Unknown |
| Noise Level | Unknown |
| Dimensions (Outdoor Unit) | Unknown |
| Weight (Outdoor Unit) | Unknown |
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