Equipment installed on this project
Casares: Johnson JSP34YN 3-Phase Inverter Pool Heat Pump — 33 kW R32 Installation
Case Study: Pool Heating with TÜV Rheinland A-Rated Johnson JSP34YN, Core-Drilled Wall Penetrations and Three-Phase Electrical Feed
Johnson JSP34YN installed with flow and return through wall penetrations
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Positioned with clearance for airflow and servicing
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Energy label: A-class, certified by TÜV Rheinland
The Challenge: Heating a Casares Hillside Villa Pool
The Casares villa sits in the Sierra Bermeja foothills, where mild but breezy spring and autumn conditions push down water temperatures even when air temperatures are comfortable. The owners wanted dependable year-round pool heating. Several site-specific challenges shaped the design:
- Existing plant room contained an ageing Coral Filtro Serie 92 sand filter, single-speed circulation pump and a galvanised pressurised vessel — water-side hydraulics needed re-piping to integrate a heat pump bypass
- No existing pool heating circuit — the heat pump position is on the opposite side of a 200 mm rendered masonry wall from the plant room
- Insufficient electrical capacity in the existing pool circuit — the JSP34YN draws up to 8.6 A on three-phase 380 V and could not share the filtration circuit
- Mountain-village location means winter air temperatures occasionally drop to 4–6 °C overnight; system needed to operate reliably across a wide ambient range
- Owners wanted comfortable swimming from early spring through to late autumn
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Existing plant room: Coral Filtro Serie 92, pump and PVC valves
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Hydraulics retained and reused to integrate the heat pump
Our Recommendation: Johnson JSP34YN Three-Phase Inverter Heat Pump
After surveying the pool volume, the plant room layout and the available three-phase supply at the main board, our specialists specified the Johnson JSP34YN — the top-of-range three-phase inverter model from EAS Electric Smart Technology's Spanish-built Johnson pool heat pump line. Here is why it was the correct fit:
Full DC Inverter, 7.7–33.2 kW Heating Range
Variable-speed compressor modulates from 7.7 kW up to 33.2 kW (at 26 °C air / 26 °C water), so the same unit can comfortably maintain the main pool at part load on warm days and ramp up to full output on cold spring mornings
COP Up to 14.6 — TÜV Rheinland Verified
Tested COP of 6.11 to 14.6 at high-temperature conditions and 4.9 to 8.68 at low-temperature conditions. Independently certified A-class energy rating by TÜV Rheinland — the highest classification available for pool heat pumps in Europe
R32 Low-GWP Refrigerant (3.3 kg, GWP 675)
Next-generation refrigerant with 68 % lower global warming potential than R410A. CO₂ equivalent of 2.2275 tonnes — fully compliant with EU F-Gas Regulation 517/2014 and future-proof for the 2025–2030 phase-down
Three-Phase 380 V / 3N / 50 Hz Operation
Three-phase wiring delivers smoother current draw, lower line losses and balanced loading on the villa's main board — ideal for a property already equipped with a 3-phase Endesa supply
Quiet 30–36 dB(A) at 10 m, Whisper-Quiet Mode at 20 dB(A)
Noise output at 10 m is 30–36 dB(A) (50–57 dB(A) at 1 m). In silent mode the unit drops to 20 dB(A) — quieter than a calm garden — important for an upmarket villa where the heat pump sits within a few metres of the pool terrace
Wide Operating Range: -15 °C to +43 °C
Fully serviceable across the Casares climate envelope, from cold mountain mornings to peak summer afternoons. Defrost control and titanium heat exchanger handle moisture and salt-pool chemistry without degradation
Plant Room Integration: Working With What Was There
The existing Casares plant room housed a Coral Filtro Serie 92 sand filter, a Speroni-style single-stage circulation pump and a galvanised pressure vessel feeding the auxiliary water circuit. A heat pump install of this size would normally tempt a complete rip-out, but the existing equipment was sound and the owner preferred to keep the proven hydraulics. We integrated the JSP34YN around the existing kit:
- Two new 110 mm core-drilled penetrations through the rendered masonry wall — one for flow, one for return — neatly aligned and sleeved to prevent abrasion of the PVC pipework
- Heat pump teed off the pump-to-filter loop downstream of the Coral filter so the JSP34YN only ever sees clean filtered water — extending the life of the titanium heat exchanger
- New PVC ball valves and union fittings on flow and return so the heat pump can be isolated for service without draining the rest of the pool circuit
- Pressure-tested to 1.5 × working pressure for 30 minutes — no leaks recorded
- Existing Coral Filtro Serie 92 and circulation pump retained and re-commissioned; backwash routine documented for the owner
- Run-and-return PVC pipework sloped to drain so the heat exchanger can be winterised if the owner ever leaves the system unused for an extended period
110 mm penetrations marked and sleeved before pipe routing
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Clean penetration for PVC pipework — close-up
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New PVC bypass with isolation valves for service without draining
Three-Phase Electrical Infrastructure — Done Properly
Unlike a typical 230 V single-phase residential pool heat pump, the JSP34YN runs on 380 V / 3N / 50 Hz with a maximum current of 8.6 A per phase. That gives a smoother, more efficient draw, but it also means the electrical work has to be specified and protected as a true three-phase circuit. Our REBT-qualified electricians completed:
- New three-phase + neutral + earth cable run from the villa's main distribution board to the pool plant room — sized for continuous duty with allowance for voltage drop on the 22 m run
- Dedicated three-phase MCB with correctly co-ordinated curve, plus four-pole RCD (Type A, 30 mA) installed in a new IP-rated DIN-rail consumer unit beside the pool plant
- Five-conductor armoured cable routed through corrugated conduit and clipped to the wall in compliance with REBT ITC-BT-31 (swimming pool installations)
- New IP-rated isolator switch installed within sight of the heat pump for safe servicing and emergency shut-off
- Earth bonding cross-connected to the existing pool equipotential bonding system — verified with continuity test and recorded on the install certificate
- Insulation resistance and earth loop impedance tests carried out and certified to REBT (Reglamento Electrotécnico de Baja Tensión, Real Decreto 842/2002)
A dedicated three-phase feed prevents nuisance tripping, eliminates voltage imbalance on the existing single-phase pool circuit and gives the inverter compressor the clean, stable supply it needs for full warranty cover. The new consumer unit also makes future maintenance — or addition of a second appliance such as a pool cover motor or salt chlorinator — straightforward and code-compliant.
Three-phase terminals 380–415 V with neutral and earth
Existing controls retained; heat pump on its own circuit
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New IP consumer unit with three-phase MCB and RCD
Verified Efficiency Benefits — Backed by Independent Sources
The performance figures for the Johnson JSP34YN are not marketing claims — they are TÜV Rheinland-certified and consistent with how independent regulators describe modern inverter pool heat pumps:
COP up to 14.6 — A-class TÜV Rheinland rating
Independently verified by TÜV Rheinland to EN 14511-4 (FPP classification). A COP of 14.6 means the unit delivers 14.6 kW of heat into the pool for every 1 kW of electrical input at part-load — far above any gas or resistance heater
Source: TÜV Rheinland (data on JSP34YN nameplate)Inverter pool heat pumps recognised as renewable heat by the EU
Pool heat pumps qualify as renewable energy under Directive (EU) 2018/2001 (RED II) provided their Seasonal Performance Factor exceeds 2.5. The JSP34YN's part-load COPs comfortably clear that threshold across the Costa del Sol climate
Source: European Commission — Directive (EU) 2018/2001 (RED II)R32 has 68 % lower GWP than R410A — and is required by F-Gas
R32 has a GWP of 675 versus 2,088 for R410A. EU Regulation 517/2014 — and its 2024 successor (EU) 2024/573 — drives the phase-down of high-GWP refrigerants. R32 is the long-term standard for new pool heat pumps in Europe
Source: EU Regulation (EU) 2024/573 on fluorinated greenhouse gasesInverter compressors deliver 40–60 % savings vs fixed-speed units
Variable-speed compressors run continuously at low load instead of cycling on/off at full power. This eliminates the inrush/cooldown losses of fixed-speed units and is the primary efficiency advantage of modern pool heat pumps
Source: European Heat Pump Association (EHPA)Extended swimming season — March to November on the Costa del Sol
With a heated pool maintained at 27–28 °C and a pool cover overnight, owners on the western Costa del Sol typically swim from March through November rather than the unheated June–September window
Source: Energy Saving Trust (UK) — Swimming Pool Heat PumpsVerified specification figures throughout this case study are taken directly from the JSP34YN data plate (model JSP34YN, serial AX25122406100226271, manufactured by EAS Electric Smart Technology, S.L., Redován, Alicante).
"The Johnson JSP34YN is genuinely my favourite pool heat pump in the Spanish market right now. The headline figures — 33 kW output, COP of 14.6, A-class TÜV Rheinland — are real, not marketing. But what matters more on a Casares villa job like this is how the unit behaves in part-load. On a mild April morning when the pool is 24 °C and the air is 18 °C, the inverter ramps the compressor down to maybe 25–30 % output, sips current at 2 kW or less, and just keeps the water gently moving up to set point. That is when you get those big COP numbers. The three-phase 380 V supply was already at the main board, so it made obvious sense to use it — three-phase gives smoother torque on the compressor, lower copper losses on the cable run, and avoids loading any single phase of the villa's incoming Endesa supply."
Rob Greeves
HVAC Director, Agua Therm
"When clients hear 'three-phase' they sometimes assume it is more dangerous or more complicated. It is neither — but it has to be installed by an electrician who actually understands REBT ITC-BT-31, the section of the Spanish low-voltage code that covers swimming-pool electrical installations. We pulled a five-core armoured cable from the villa's main board through corrugated conduit, clipped on saddle straps, and terminated it into a new IP-rated DIN-rail consumer unit at the plant room. From that consumer unit, the JSP34YN gets its own three-phase MCB and a Type A 30 mA four-pole RCD. We then bonded the heat pump's chassis earth into the pool's existing equipotential bonding network — that is the safety detail that is most commonly missed by non-specialists, and it is the one that protects swimmers from any stray voltage if a fault ever develops on a piece of pool equipment. Insulation resistance and earth loop impedance were measured and recorded. The owner has the install certificate on file for any future inspection or insurance enquiry."
Craig Whitham
Electrical Director, Agua Therm
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During installation: core drill, tools and unit positioned ready for pipe connection
Professional Installation Process
Our certified technicians completed the installation over two days, working around an occupied villa with minimal disruption:
- 1Site survey of the pool plant room, the proposed heat pump position and the cable route from the main distribution board
- 2Heat-loss calculation based on pool volume, surface area, average wind exposure and a target setpoint of 27–28 °C
- 3Two new 110 mm core-drilled penetrations through the rendered masonry wall for the JSP34YN flow and return; sleeved and weather-sealed
- 4JSP34YN positioned on level paving with anti-vibration feet and 600 mm clearance to wall for unrestricted air intake and discharge
- 5Hydraulic connection downstream of the Coral Filtro Serie 92 with new PVC ball valves, union fittings and a manual bypass for service
- 6Five-core 380 V cable installed from main board to new DIN-rail consumer unit at plant room — sized for continuous duty with voltage-drop allowance on the 22 m run
- 7Three-phase MCB and four-pole 30 mA Type A RCD wired into the new consumer unit; equipotential bonding extended to the heat pump chassis
- 8F-Gas vacuum and pressure check on factory-charged refrigerant circuit; no leaks recorded on hold test
- 9Commissioning: full heating cycle, flow rate verification, defrost cycle test, controller setpoints configured, owner walkthrough on filtration interaction and winterisation
- 10Insulation resistance, earth loop impedance and equipotential bonding continuity tested and recorded on REBT install certificate
Installation Results
7.7–33.2 kW
Heat Output
14.6
COP (peak)
R32 (GWP 675)
Refrigerant
30–36 dB(A)
Noise at 10 m
JSP34YN data plate (serial AX25122406100226271) and manufacturer datasheet
Why Johnson Pool Heat Pumps in Casares and the Western Costa del Sol?
Johnson (manufactured by EAS Electric Smart Technology, S.L., Redován, Alicante) is one of the strongest specialist pool heat pump brands in Spain — and the right fit for hillside villa work in Casares, Manilva, Estepona and Sotogrande:
- Spanish-manufactured and -distributed — short supply chain, parts available locally on the Costa del Sol within days
- Full DC inverter technology across the range, including the high-output three-phase JSP34YN reviewed here
- A-class energy efficiency independently certified by TÜV Rheinland to EN 14511-4
- R32 refrigerant standard across all current models — compliant with current and 2024 successor F-Gas regulation
- IPX4 weather rating — engineered for year-round outdoor exposure on the Costa del Sol, including coastal salt air
- Titanium heat exchanger as standard — handles salt-chlorinated and reverse-osmosis pool water without corrosion
- Competitive pricing versus equivalent Zodiac, Hayward, Pentair or Astralpool three-phase models
Location: Casares, Costa del Sol
Agua Therm provides professional pool heat pump installation throughout the western Costa del Sol, including Casares, Casares Costa, Manilva, Sotogrande, Estepona, San Pedro, Benahavís and Marbella.
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About the Author
Ben Hayden
English-Speaking Electrician & Independent Energy Advisor
Ben Hayden is an English speaking electrician and independent energy advisor based in Marbella, Spain, with over 15 years of electrical experience across Europe. He provides independent energy and electrical checks for overseas property owners and managers across the Costa del Sol — helping clients cut electricity bills, navigate Spanish regulations, and make confident decisions on solar PV, heat pump, EV charger and battery storage projects.
Ben advises in plain English on projects where the paperwork is in Spanish and the stakes are high. His writing has appeared in ExpatArrivals, The Olive Press, Euro Weekly News, BuildingTalk and pv magazine.