PoolControls Zenheat ZHS21 Horizontal Airflow Inverter Pool Heater with R32 Refrigerant

For residential pool and spa heating, the Zenheat ZHS 21 uses a full-inverter air-source heat pump system with R32 refrigerant and a titanium heat exchanger. A DC inverter fan motor directs air horizontally through the unit, while automatic defrosting is provided through a 4-way valve. The ZHS 21 operates from a 240V single-phase 50Hz power supply.

Maximum power input is rated at 3.2 kW and maximum current at 14.7 A, with a specified water flow volume of 6.5 m³/h. The heater has a working temperature range of -15°C to 43°C, establishing the operating temperature conditions specified for the model. These electrical and flow ratings distinguish the ZHS 21 within the range.

The unit is housed in an ABS casing with an IPX4 waterproof level. Noise is specified at 45–56 dB(A) at 1 metre and 25–36 dB(A) at 10 metres. Its net weight is 58 kg, while the gross weight is 69 kg, providing the relevant product and packaged weights for handling and installation planning.

The ZHS 21 has net dimensions of 925 × 364 × 642 mm and package dimensions of 990 × 435 × 760 mm. The stated dimensions provide the physical measurements for the heater and its packaged form, with the full-inverter heating and control components contained within the product enclosure.

Features

• A high-end Mitsubishi compressor forms part of the ZHS 21 heating system.
• The full-inverter configuration is specified with high efficiency COP of up to 16.
• Built-in WiFi provides connectivity for the heater's control functions.
• The waterproof touchscreen display provides a dedicated interface for operating the unit.
• A refrigerant system pressure gauge gives a visible reference for system pressure.
• The EEV provides the precise refrigerant gas control specified for the system.
• Hot gas defrosting forms part of the unit's defrosting arrangement.