The outdoor unit has been charged with refrigerant.
When connect the pipe to the unit or dismantling the pipe from the unit, please follow the figure shown, use spanner and torque spanner together.
When connect cone nut, the inner side and outside of cone nut should paste with refrigerant oil. Use hand to twist 
Referring to Table I to confirm the fasten torque. (too tight may damage nut leading to leakage)
Check if the connection pipe leaks, then do heat insulation treatment, as below figure shown. 
Only use seal cushion to bind the joint part of air pipe and heat insulation parts.
Spanner
HDU-42HT03/H specifications
The Haier HDU-42HT03/H is a cutting-edge heating, ventilation, and air conditioning (HVAC) solution designed to provide comfort and efficiency for residential and commercial spaces. This model stands out due to its innovative features, advanced technologies, and reliable performance.One of the key features of the Haier HDU-42HT03/H is its impressive cooling and heating capacity. With a nominal cooling capacity of 4.2 kW and a heating capacity of 5.0 kW, this model is suitable for medium-sized rooms, ensuring that spaces remain comfortable regardless of outdoor temperatures. Its Inverter technology allows for precise control of the compressor speed, resulting in faster cooling and heating, less energy consumption, and quieter operation.
The unit’s energy efficiency is highlighted by its high SEER (Seasonal Energy Efficiency Ratio) and SCOP (Seasonal Coefficient of Performance) ratings, which contribute to lower electricity bills and reduced environmental impact. The HDU-42HT03/H also features a programmable thermostat, allowing users to set specific heating and cooling schedules, optimizing energy use while maintaining comfort.
For enhanced air quality, the Haier HDU-42HT03/H comes equipped with a multi-stage filtration system that effectively captures dust, allergens, and other airborne particles. This ensures that the air circulated within the space is clean and healthy, making it an excellent choice for individuals with allergies or respiratory issues.
Additional technological advancements in the HDU-42HT03/H include the use of eco-friendly refrigerant, which minimizes its impact on the environment. The model also integrates smart technology, allowing for remote operation via a smartphone application. This feature enables users to control the unit from anywhere, providing added convenience and flexibility.
In terms of design, the Haier HDU-42HT03/H is sleek and modern, allowing it to blend seamlessly into various interior styles. Its compact structure makes it suitable for a variety of installation environments, whether in homes or businesses.
Overall, the Haier HDU-42HT03/H is a top-tier HVAC solution, boasting powerful performance, energy efficiency, and user-friendly features. It is an excellent choice for anyone looking to enhance their indoor climate control with a reliable and effective system.