Duratech HS35 Hot Splash Heat Pump For Swimming Pool User Manual

Duratech HS35 Hot Splash Heat Pump for Swimming Pool: Complete Manual

The duratech HS35 Hot Splash Heat Pump For Swimming Pool is a compact plug-and-play heating solution designed for small above-ground and residential swimming pools. It uses ambient outdoor air to transfer heat into the pool water, helping extend the swimming season while using substantially less electricity than conventional electric resistance heaters.

With a rated heating capacity of up to 3.35 kW under favorable test conditions, the HS35 is suitable for pools with a volume of up to approximately 12 m³. Its titanium heat exchanger supports compatibility with treated pool water, while the R32 refrigerant and inverter-free design provide straightforward operation and maintenance.

The unit is intended for pool owners who want simple seasonal heating without installing a large permanent heating system. It is especially practical for above-ground pools, compact garden pools, and installations where space is limited. The horizontal fan arrangement, lightweight construction, and 32 mm water connections make it easier to position near compatible circulation equipment.

For best results, operate the heat pump outdoors when the air temperature is at least 10°C, keep the pool covered when not in use, and run the circulation pump whenever heating is enabled. The duratech HS35 Hot Splash Heat Pump For Swimming Pool works most efficiently when water flow, filtration, and installation clearances are correct.

Duratech HS35 Specifications and Key Features

The following specifications describe the HS35 model and its intended operating conditions. Actual performance varies with air temperature, humidity, pool size, insulation, water flow, and the use of a pool cover.

• Product type: Air-source swimming pool heat pump.
• Recommended maximum pool volume: Approximately 12 m³.
• Heating capacity: Up to 3.35 kW at 27°C air and 26°C water; approximately 2.65 kW at 15°C air and 26°C water.
• Coefficient of performance: Up to approximately COP 6 under favorable test conditions and approximately COP 5.1 at lower test temperature.
• Power input: Approximately 0.56 kW under rated conditions.
• Electrical supply: 230 V, single phase, 50 Hz.
• Running current: Approximately 2.55 A; maximum running current approximately 3 A.
• Refrigerant: R32, with a listed charge of approximately 0.24 kg.
• Heat exchanger: Titanium.
• Nominal water flow: Approximately 2 m³/h.
• Water connection: 32 mm.
• Airflow: Approximately 700 m³/h.
• Operating air temperature: Minimum approximately 10°C.
• Noise level: Approximately 48 dB(A) at 10 m under stated test conditions.
• Weight: Approximately 15 kg.

How to Install and Set Up the Duratech HS35

1. Choose an outdoor location at least 2 m from the pool and place the unit on a level, solid, load-bearing base.
2. Leave at least 0.3 m of clearance around the unit and at least 1.5 m of unobstructed space in front of the fan outlet. Never install the heat pump indoors or in an enclosed shed.
3. Switch off the pool circulation system before connecting hoses. Route filtered water through the heat pump before it returns to the pool. Chemical dosing equipment should be installed downstream of the heat pump.
4. Connect the 32 mm water hoses securely, check that seals are correctly seated, and open the relevant valves.
5. Start the circulation pump and inspect every connection for leaks. Do not energize the heat pump until water is flowing through it.
6. Connect the unit to a properly earthed outdoor electrical outlet that matches the rated supply. Electrical work should be completed by a qualified person.
7. Turn on the circulation pump, then switch on the heat pump. Allow several minutes for the unit to begin producing visibly warmer return water.
8. For efficient heating, use a thermal pool cover, maintain clean filtration, and operate the system during the warmest part of the day.

If the unit does not start, confirm that the water pump is running, the filter is not blocked, valves are open, the ambient temperature is above the minimum operating level, and the power supply is connected. Keep fingers, tools, and objects away from the fan.

Duratech HS35 Troubleshooting Guide

Heat pump does not start

Check the outdoor socket, circuit protection, power switch, and plug connection. Confirm that the circulation pump is operating and that water is passing through the heat pump. The unit may also delay starting to protect the compressor.

Water is not getting warmer

Verify that the filter is clean and that the water flow is close to the required level. Confirm that the fan has adequate clearance and that the air temperature is above 10°C. A pool cover can significantly reduce heat loss, particularly overnight or during windy weather.

Low water flow or restricted circulation

Clean the pool filter, inspect hoses for kinks, remove trapped air, and check that all valves are fully open. Stop the system if leaks, unusual vibration, or persistent flow problems occur.

Code NA

This indication can appear when the ambient air is too cold for operation or when the internal heat-pump temperature is below its operating threshold. Allow the weather to warm and keep the unit switched off until conditions improve.

Code AL1

AL1 indicates a possible heat-pump sensor fault. Switch the unit off, wait briefly, and restart it once. If the code returns, stop using the appliance and contact the installer, authorized service center, or qualified refrigeration technician. Do not open the refrigerant circuit.

For support, keep the model designation, serial number, purchase documentation, installation details, and a description of the symptom available. Warranty terms and service contacts can vary by country and distributor, so use the documentation supplied by the seller or the manufacturer’s authorized support channel.

Duratech HS35 Pros and Cons

Advantages

• Compact design: Its small footprint and approximately 15 kg weight suit space-limited pool installations.
• Simple operation: The plug-and-play format requires fewer configuration steps than many larger permanent pool heating systems.
• Efficient heat transfer: The stated COP can reach approximately 6 under favorable conditions, making an air-source heat pump more efficient than direct electric heating in suitable weather.
• Pool-water compatibility: The titanium heat exchanger is appropriate for normal treated pool water when chemical levels are correctly maintained.
• Small-pool suitability: The unit is well matched to pools up to approximately 12 m³, particularly when combined with a thermal cover.
• Lower operating noise: The stated sound level is approximately 48 dB(A) at 10 m, although placement affects perceived noise.

Limitations

• Weather dependent: Heating performance decreases as outdoor air becomes cooler, and operation is not intended below approximately 10°C.
• Limited pool capacity: Larger pools may require a higher-capacity heat pump or a longer heating period.
• No rapid heating expectation: Like most compact air-source pool heaters, it is designed for gradual temperature maintenance rather than instant heating.
• Requires circulation: The filter pump must provide suitable water flow whenever the heat pump operates.
• Needs good heat retention: An uncovered pool can lose heat quickly through evaporation, especially overnight.

The duratech HS35 Hot Splash Heat Pump For Swimming Pool is best for owners of compact pools seeking efficient seasonal heating and simple installation. Owners of large pools, cold-climate installations, or users needing rapid temperature increases may need a larger heat pump or another heating technology.