Above Ground Pool Heat Pumps
Heat Pumps for Above-Ground Swimming Pools
Compact Poolex heating for framed, wooden and small garden pools, with practical sizing and connection advice
Above-ground pools lose heat quickly through the surface and exposed walls, so the best heat-pump result starts with a cover and a realistic swimming season. This category brings together compact Poolex Nano models and the more substantial Silverline Top for customers who want warmer water without using a direct electric heater for every degree.
The current Poolex Nano FI is a full-inverter, reversible model in 3 kW and 5 kW sizes, published for pools up to 20 and 30 m3 respectively under the stated conditions. Silverline Top is the step up for medium and larger garden pools where compact Nano output is not enough.
Never select only from a pool kit’s nominal litres. We also use surface area, desired temperature, location, cover quality and the coldest air temperature at which you expect it to work.
Price range: £412.00 through £536.00 (inc VAT)
Out of stock
Price range: £575.00 through £595.00 (inc VAT)
8% Off
Out of stock
Price range: £1,083.00 through £3,076.00 (inc VAT)
Nano FI for Compact Pools
The Poolex Nano FI continuously adjusts compressor and fan speed. Its 3 kW and 5 kW models use 32 mm connections, built-in 2.4 GHz Wi-Fi and heating/cooling operation. Poolex publishes operation down to -7 C, but output and COP are lower in cold air.
The older Nano Ultra Compact remains visible for reference while out of stock; use the current Nano FI page for the replacement option.
When to Step Up to Silverline Top
The Silverline Top Full Inverter suits larger above-ground pools and colder or longer-season duties. Its top-discharge layout can also help where horizontal exhaust clearance is awkward.
Use a proper bypass and the specified flow. Adaptors for 32/38 mm pool hose must not become a severe restriction on a larger heat pump.
Make an Above-Ground Pool Easier to Heat
Fit a compatible cover whenever the pool is not being used, limit wind exposure and run filtration long enough for the heat pump to do its work. Heat in steady blocks rather than expecting a cold pool to warm minutes before swimming.
Our advice: tell us the exact pool dimensions and months of use. We will not recommend the smallest unit just because it can eventually heat the water in ideal weather.
Related Heating and Installation Categories
All pool heat pumps · Poolex heat pumps · Pool covers · Pool plumbing · Pool pumps and filtration
Frequently Asked Questions
Which Poolex model is for small above-ground pools?
Nano FI is the compact full-inverter range, with published 3 kW and 5 kW models.
What pool volumes does Poolex publish for Nano FI?
Up to 20 m3 for Nano 3 and 30 m3 for Nano 5 under the stated conditions.
Can Nano FI cool as well as heat?
Yes. It has heating, cooling and automatic modes.
Does Nano FI have Wi-Fi?
Yes, built-in 2.4 GHz Wi-Fi for the supported Poolex app.
Which connections does Nano FI use?
The current manufacturer specification lists 32 mm connections; check the supplied UK adaptor package.
Why is Nano Ultra Compact still shown?
It is an older out-of-stock product retained for reference; Nano FI is the current alternative.
When should I choose Silverline Top?
For a larger pool, colder duty or where the compact Nano output is insufficient.
Can I heat an Intex or Bestway pool?
Yes when the heat pump, flow adaptors, electrical supply and cover suit the exact pool.
Do exposed pool walls matter?
Yes. Wind and exposed sides add heat loss compared with an insulated in-ground pool.
Can the heat pump run when the filter pump is off?
No. It needs water flow and normally interlocks or faults when circulation stops.
Will a 5 kW unit add five degrees per hour?
No. kW is heat output, not degrees per hour; warming time depends on water mass and heat loss.
Can you size from pool diameter and depth?
Yes. Provide the exact dimensions, normal fill depth, cover and desired season.
Why is a pool cover so important?
Most heat escapes from the water surface. A suitable cover can reduce heat loss dramatically and may change the heat-pump size and running cost.
Does the headline kW stay the same in cold weather?
No. Heat output and COP change with air temperature, water temperature and humidity. Compare the cold-condition performance for your season.
What does COP mean?
Coefficient of performance compares heat delivered with electrical input at stated test conditions. It is not a fixed year-round efficiency figure.
Why is a bypass useful?
A correctly set bypass helps keep flow through the heat exchanger within the permitted range and makes isolation and servicing easier.
Is water beneath the outdoor unit a leak?
Often it is normal condensate from the evaporator, especially in damp weather. Check that it is clear water and that the condensate drain is unobstructed.
Can the unit be enclosed in a shed?
Normally no. It needs the manufacturer clearances and unrestricted outdoor airflow; recirculating cold exhaust air reduces output and efficiency.
Who should install the electrical supply?
A qualified electrician should provide the correct protected circuit, isolation and cable sizing. Plug-fitted models still need a suitable outdoor supply.
How do I prevent frost damage?
Follow the exact winterising instructions. If the circulation is stopped, drain all trapped water from the heat exchanger and pipework.
Can you help size a heat pump?
Yes. Send water volume, surface area, target temperature, months of use, location, cover type, filtration flow and electrical supply.
Should chemical dosing enter before the heater?
Follow the installation manual; dosing equipment is normally placed downstream so concentrated chemical cannot enter the heat exchanger.
Why does flow matter?
Too little flow can cause faults or poor heat transfer; too much can exceed the unit limits. Use the specified range for the exact model.
How long will initial heating take?
It depends on water volume, starting and target temperatures, weather, cover and the unit’s output at those conditions. Maintaining temperature is easier than the first warm-up.
