Poolex Silverline On/Off Heat Pumps for Swimming Pools

Poolex Silverline On/Off Heat Pumps for Swimming Pools

Straightforward air source heat pump heating for outdoor swimming pools

Poolex Silverline On/Off Heat Pumps for Swimming Pools is a Poolex Silverline On/Off heat pump designed for seasonal pool heating where simple dependable operation is preferred. It gives customers a more efficient way to warm pool water than a standard direct electric heater because it uses air source heat pump technology to transfer heat from the surrounding air into the water.

In the UK, outdoor water temperatures can swing quickly between warm days, cool nights and windy conditions. A correctly sized heat pump helps smooth out those changes, making the swimming pool more comfortable and easier to manage through the season. It is especially useful where the aim is to extend usable time, improve comfort, or maintain a steadier temperature range.

This range is best considered by model size, water volume, desired temperature, insulation, cover use, wind exposure and flow rate. The available model options for this product are: Silverline 55, Silverline 70, Silverline 90, Silverline 120, Silverline 150, Silverline 220.

As with all heat pumps, actual performance depends on air temperature, water temperature, humidity and installation quality. Warm air gives the heat pump more energy to collect, while colder air reduces output and increases running time. Using a cover when the pool or pond is not in use can make a significant difference because evaporation is one of the biggest causes of heat loss.

Why flow, bypass and installation setup matter

A heat pump performs best when the water flow through the unit is controlled. Too little flow can cause safety cut outs, while too much flow can reduce heat transfer time and make the unit work harder than necessary. This is why a bypass kit is normally recommended on pool and pond heat pump installations.

A bypass allows part of the water to pass through the heat pump and part to continue around it, making it much easier to balance flow, isolate the heater for maintenance, and keep the filtration system running sensibly. On many installations you may also need extra 38mm hose, hose clips, pressure pipe or unions depending on the pipework already fitted.

Key benefits

• Efficient air source heat pump heating for the intended pool, swim pond or pond system.
• Digital control with wi-fi / app control where supported for easier temperature management.
• Useful for extending the swimming season or maintaining a steadier water temperature.
• Works best alongside a pool cover or good insulation to reduce heat loss.
• Can be installed with a bypass kit to control flow and simplify maintenance.
• Titanium heat exchanger style technology is commonly used on pool heat pumps for corrosion resistance with properly maintained water.

Technical information

• Type: On/off air source swimming pool heat pump
• Models: Silverline 55, 70, 90, 120, 150 and 220
• Maximum heating capacity at A26/W26: 5.39 to 21.72kW
• Maximum heating capacity at A15/W26: 3.9 to 15.3kW
• Maximum COP: Up to 6.22
• Maximum power input: 1.29 to 5.46kW
• Voltage: 230V
• Refrigerant: R32
• Noise level: Under 30 to 40dB
• Dimensions: 765 x 310 x 490mm to 1067 x 405 x 692mm
• Weight: 39 to 62kg
• Nominal flow: 1.86 to 7m³/h
• Water connections: 50mm / 1½ inch
• Wi-Fi control: Optional / model-specific

Available model options

For easier comparison, the main model options are shown below with their key output and electrical input figures. Heat pump performance always depends on the test condition shown, so compare the same A/W condition when choosing between models.

• Silverline 55 – SKU 115139
  Output A26/W26: 5.39kW
  Input: see full technical information
  Maximum COP: up to 6.22
• Silverline 70 – SKU 115146
  Output A26/W26: 7.02kW
  Input: see full technical information
  Maximum COP: up to 6.22
• Silverline 90 – SKU 115147
  Output A26/W26: 9.31kW
  Input: see full technical information
  Maximum COP: up to 6.22
• Silverline 120 – SKU 115148
  Output A26/W26: 12.5kW
  Input: see full technical information
  Maximum COP: up to 6.22
• Silverline 150 – SKU 115149
  Output A26/W26: 15.24kW
  Input: see full technical information
  Maximum COP: up to 6.22
• Silverline 220 – SKU 115151
  Output A26/W26: 21.72kW
  Input: see full technical information
  Maximum COP: up to 6.22

Recommended optional extras

For a neater and more controllable installation, consider adding the appropriate heat pump bypass kit and fittings. The same approach used on the Poolex Nano product page is useful across many heat pump installations because it helps control flow and makes servicing easier. On larger hard-plumbed systems, use the correct 1½ inch or 2 inch fittings for the selected model rather than forcing small flexible hose connections.

• Heat pump bypass kit: helps control flow through the heat pump and allows isolation for maintenance.
• 38mm vac hose: useful where a compact pool heat pump is being connected using flexible 38mm hose.
• Stainless steel hose clips: useful for securing hose connections on above ground and flexible hose installations.
• Rubber mounting feet: useful on larger heat pumps where anti-vibration support is recommended.

Heating advice

Choose the heat pump size using real water volume, how exposed the pool or pond is, whether a cover will be used, the desired temperature and the season you want to use it in. A heat pump that is too small may still heat the water, but it will take longer, run harder and be less satisfying in cooler conditions.

For best results, keep filtration running while heating, protect the unit from poor airflow, use a cover when possible and avoid placing the heat pump in a tight enclosed space. If the installation is on a koi pond, always consider fish health, oxygen levels and gradual temperature changes rather than chasing sudden temperature increases.

Helpful heating links

• Browse pond heating
• Browse pond air source heat pumps
• Browse swimming pool heating
• Standard flexible pond hose
• Heavy duty flexible pond hose