💧 WHSR403/4 | 4.0hp (3.0kW) 3Ø Hydrostar Mk4 Commercial Pool Pump

Next-Generation Commercial Pump Delivering Superior Flow, Ultra-Quiet Operation and Outstanding Energy Efficiency for Professional Aquatic Facilities

📋 Product Overview

The Certikin Hydrostar MK4 4.0hp (3.0kW) three-phase commercial pump represents a significant technological advancement over previous generation pool pumps. Engineered specifically for commercial aquatic environments, this pump combines optimized hydraulics with innovative design to deliver substantially quieter operation and improved flow rates compared to the MK3 predecessor.

Built with UV-stabilized glass-filled polypropylene construction and featuring an enclosed glass-filled Noryl impeller, the Hydrostar MK4 is designed for reliable, long-term operation in demanding commercial settings including municipal pools, leisure centres, hotels, water parks, and large residential installations. The redesigned pump body optimizes internal flow paths, reducing turbulence and cavitation while maximizing hydraulic efficiency. With IP55-rated motor protection, 431 stainless steel shaft, and tool-free maintenance access via ergonomic lid handles, this pump delivers professional-grade performance with minimal operational complexity.

The three-phase motor configuration provides superior energy efficiency compared to single-phase alternatives, while the 6-litre strainer basket with clear polycarbonate lid enables quick visual inspection without system shutdown. This pump is ideal for facility managers seeking to upgrade aging equipment, reduce operational noise levels, lower energy consumption, and improve overall system performance.

⭐ Key Features

✅ Powerful 4.0hp (3.0kW) Three-Phase Motor – Delivers reliable, consistent performance for commercial filtration systems while consuming less energy than equivalent single-phase motors. Three-phase operation provides smoother power delivery, reduced electrical stress, and lower operating costs.

✅ Substantially Quieter Operation – Redesigned pump body and optimized hydraulics significantly reduce operational noise compared to MK3 predecessors, making this ideal for noise-sensitive environments including hotel pools, residential complexes, and indoor leisure facilities where ambient sound quality matters.

✅ Enhanced Flow Rates Through Optimized Design – Reshaped internal geometry improves hydraulic efficiency, delivering more water movement per kilowatt consumed. The improved flow characteristics reduce system head loss and enable better turnover rates without increasing power consumption.

✅ UV-Stabilized Glass-Filled Polypropylene Construction – Exceptional resistance to chemical corrosion, UV degradation, and physical impact ensures longevity even in harsh outdoor installations with aggressive chemical treatment programs. This material won’t crack, fade, or deteriorate under continuous sun exposure.

✅ Clear Polycarbonate Strainer Lid for Visual Inspection – Instantly check strainer basket status without opening the pump or interrupting operation. The transparent lid enables preventive maintenance scheduling by allowing staff to monitor debris accumulation and service only when necessary.

✅ Large 6-Litre Strainer Basket – Captures more debris before requiring cleaning, reducing maintenance frequency and labour costs. The generous capacity is particularly valuable in high-debris environments including outdoor pools with heavy foliage, storm drainage, or high bather loads.

✅ Tool-Free Lid Removal with Ergonomic Handles – Quarter-turn lock ring with integrated handles enables quick access to strainer basket without tools, simplifying routine maintenance and reducing service time. This design minimizes maintenance complexity and allows faster response to blockages.

✅ 431 Stainless Steel Motor Shaft – Superior corrosion resistance compared to standard steel, ensuring reliable long-term performance in wet environments with chemical exposure. The premium shaft material prevents rust-related failures and extends bearing life.

✅ IP55 Motor Protection Rating – Comprehensive protection against dust ingress and water jets ensures reliable operation in outdoor installations, humid pump rooms, and exposed locations. This industrial-grade protection standard guarantees dependable performance regardless of environmental conditions.

✅ 90mm Metric Half-Union Connections – Industry-standard fitting size simplifies installation and replacement, ensuring compatibility with existing piping infrastructure. The union connections enable pump removal for service without disturbing fixed piping.

🔧 Technical Specifications

Specification	Detail
Model Number	WHSR403/4
Power Rating	4.0 hp (3.0 kW)
Motor Type	Three-phase (3Ø)
Motor Configuration	WYE/STAR connection (export) / DELTA connection (Australia/NZ)
Voltage	As per motor nameplate (verify before installation)
Motor Protection	IP55 (dust and water jet protected)
Pump Housing	UV-stabilized glass-filled polypropylene
Strainer Lid	Clear polycarbonate
Impeller Type	Enclosed glass-filled Noryl
Motor Shaft Material	431 stainless steel
Strainer Basket Capacity	6 litres (molded polypropylene)
Inlet Connection	90mm metric half-union
Outlet Connection	90mm metric half-union
Minimum Pipe Size (Inlet)	80mm
Minimum Pipe Size (Outlet)	80mm
Lid Lock System	Quarter-turn with ergonomic handles (tool-free)
Drain Plugs	Yes (2) for winterization/maintenance
Maximum Operating Temperature	40°C (104°F)
Minimum Operating Temperature	4°C (39.2°F)
Maximum Test Pressure	35 psi (must be performed by trained professional)
Rotation Direction	Clockwise (viewed from motor fan cowl)
Required Clearance	Adequate ventilation around motor and fan cowl
Installation Location	Minimum 1.5m (5 ft) from water’s edge
Warranty Period	1 year (commercial installations)

💰 Usage Costs & Running Expenses

📊 Annual Running Cost Calculation

Understanding the true operating cost of commercial pool equipment is essential for accurate budgeting and ROI analysis. Let’s calculate the real-world annual running costs for the Hydrostar MK4 based on current UK commercial electricity prices.

Base Calculation Parameters:

• Power consumption: 3.0 kW (continuous operation)
• UK commercial electricity rate: £0.26 per kWh (Q4 2025 average, based on current market data)
• Typical seasonal operation: 180 days (6 months, May-October for outdoor pools)
• Typical daily runtime: 8 hours per day (standard filtration cycle)

Standard Seasonal Operation (Outdoor Pool):

• Annual operating hours: 8 hours/day × 180 days = 1,440 hours/year
• Energy consumption: 3.0 kW × 1,440 hours = 4,320 kWh/year
• ✅ Annual electricity cost: 4,320 kWh × £0.26 = £1,123.20

Extended Season Operation (Indoor/Year-Round Facility):

• Annual operating hours: 8 hours/day × 365 days = 2,920 hours/year
• Energy consumption: 3.0 kW × 2,920 hours = 8,760 kWh/year
• ✅ Annual electricity cost: 8,760 kWh × £0.26 = £2,277.60

High-Use Commercial Operation (24/7 Continuous):

• Annual operating hours: 24 hours/day × 365 days = 8,760 hours/year
• Energy consumption: 3.0 kW × 8,760 hours = 26,280 kWh/year
• ✅ Annual electricity cost: 26,280 kWh × £0.26 = £6,832.80

⚡ Three-Phase Efficiency Advantage

The three-phase motor in the Hydrostar MK4 offers significant efficiency advantages over equivalent single-phase motors:

Comparative Analysis vs Single-Phase Equivalent:

• Single-phase 4.0hp motor typical efficiency: ~85%
• Three-phase motor typical efficiency: ~92%
• Efficiency improvement: ~7-8% energy savings

Cost Impact on Standard Seasonal Operation:

• ❌ Equivalent single-phase pump: ~4,640 kWh × £0.26 = £1,206.40/year
• ✅ Hydrostar MK4 three-phase: 4,320 kWh × £0.26 = £1,123.20/year
• 💰 Annual saving: £83.20
• 📈 10-year saving: £832

🎯 Real World Examples & Applications

🏊 Municipal Swimming Pool – Outdoor

A 25m outdoor municipal pool operating seasonally requires reliable high-flow pumps for main circulation. The Hydrostar MK4 provides the necessary flow capacity while keeping noise levels acceptable for residential neighborhoods.

• Typical runtime: 10 hours daily, May-September (150 days)
• Annual consumption: 3.0 kW × 10 × 150 = 4,500 kWh
• Annual cost: £1,170
• Application benefit: Substantially quieter operation reduces complaints from nearby residents

🏢 Hotel Pool & Spa – Year-Round Operation

A boutique hotel with indoor pool and spa requires continuous filtration with minimal noise. The Hydrostar MK4’s quiet operation makes it ideal for installations near guest accommodations.

• Typical runtime: 12 hours daily, year-round
• Annual consumption: 3.0 kW × 12 × 365 = 13,140 kWh
• Annual cost: £3,416
• Application benefit: IP55 protection ensures reliable operation in humid pool room environment

🌊 Leisure Centre – High-Traffic Facility

A commercial leisure facility with multiple pools requires dependable pumps capable of handling high debris loads. The 6-litre strainer basket reduces maintenance downtime.

• Typical runtime: 16 hours daily, year-round
• Annual consumption: 3.0 kW × 16 × 365 = 17,520 kWh
• Annual cost: £4,555
• Application benefit: Tool-free strainer access enables quick maintenance between busy periods

🏠 Large Residential Installation – Private Pool

An executive residence with substantial outdoor pool requires commercial-grade reliability with residential noise levels. The Hydrostar MK4 delivers both.

• Typical runtime: 6 hours daily, 6 months seasonal
• Annual consumption: 3.0 kW × 6 × 180 = 3,240 kWh
• Annual cost: £842
• Application benefit: Significantly quieter than older pumps, maintaining property tranquility

🔄 Upgrade Replacement – Aging Equipment

Replacing a 15-year-old pump with modern energy-efficient technology provides immediate operational benefits and long-term cost savings through improved efficiency and reduced maintenance.

• Application benefit: Modern materials eliminate corrosion issues common in older pumps
• Additional benefit: Enhanced flow rates may improve overall water quality through better turnover

💡 Cost Savings Examples

📍 Scenario 1: Upgrading from Older Single-Phase Technology

Many facilities still operate legacy single-phase pumps installed 10-20 years ago. These older pumps typically consume significantly more energy due to outdated motor technology and accumulated wear.

Comparison: Hydrostar MK4 vs 15-Year-Old 4.0hp Single-Phase Pump

Older single-phase pump characteristics:

• Power consumption: ~4.5 kW (accounting for efficiency degradation)
• Typical operation: 8 hours/day, 180 days/year
• ❌ Annual consumption: 4.5 kW × 1,440 hours = 6,480 kWh
• ❌ Annual cost: 6,480 × £0.26 = £1,684.80

New Hydrostar MK4:

• Power consumption: 3.0 kW (efficient three-phase motor)
• Same operation: 8 hours/day, 180 days/year
• ✅ Annual consumption: 3.0 kW × 1,440 hours = 4,320 kWh
• ✅ Annual cost: 4,320 × £0.26 = £1,123.20

💰 Annual Saving: £561.60 💷 5-Year Saving: £2,808 📈 10-Year Saving: £5,616

⏱ Payback Period: Depending on installation costs, typical payback in 3-4 years through energy savings alone, with additional benefits including reduced maintenance, improved reliability, and quieter operation.

📍 Scenario 2: Reducing Noise Complaints in Residential Area

A community pool received noise complaints about their older pump disturbing nearby residents. Upgrading to the Hydrostar MK4 eliminated complaints while simultaneously reducing energy costs.

Impact Analysis:

❌ Previous situation:

• Older pump: Noisy operation requiring sound enclosure modifications
• Sound enclosure cost: £800-1,200 for professional installation
• Restricted airflow from enclosure increased motor temperature
• Higher maintenance costs due to thermal stress

✅ After Hydrostar MK4 installation:

• Substantially quieter operation – no sound enclosure needed
• Saved enclosure cost: £1,000
• Better motor ventilation extends component life
• Annual energy saving: £300-400 (compared to older pump)
• Eliminated resident complaints and council inquiries

💰 Total First-Year Benefit: Sound enclosure cost avoided (£1,000) + energy savings (£350) = £1,350

📍 Scenario 3: Improving Indoor Pool Air Quality

An indoor leisure facility struggled with excessive noise and vibration from aging pumps, requiring expensive acoustical treatments. The Hydrostar MK4 addressed these issues through inherent design improvements.

Previous Annual Costs:

• ❌ Old pump energy consumption: 5.2 kW × 2,920 hours = 15,184 kWh
• ❌ Old pump annual energy cost: £3,948
• ❌ Vibration-related maintenance: £400/year (mounting repair, pipe bracket adjustment)
• ❌ Acoustic foam treatments: £1,200 (initial investment)

After Hydrostar MK4 Installation:

• ✅ New pump energy consumption: 3.0 kW × 2,920 hours = 8,760 kWh
• ✅ New pump annual energy cost: £2,278
• ✅ Reduced vibration maintenance: £100/year (minimal adjustment)
• ✅ No acoustic treatments needed: £0

💰 Annual Operating Saving: £1,970 (energy + maintenance) 💷 Acoustic Treatment Cost Avoided: £1,200 📈 3-Year Total Benefit: £7,110

📍 Scenario 4: Energy Price Protection Strategy

With UK commercial electricity prices remaining elevated (£0.26/kWh in 2025 vs £0.15/kWh in 2021), energy efficiency investments provide protection against future price volatility.

Energy Cost Trend Analysis:

• 2021 average: £0.15 per kWh
• 2025 average: £0.26 per kWh
• Increase: 73% over 4 years

Hydrostar MK4 Operating Cost at Different Energy Prices: (Based on 1,440 hours/year seasonal operation)

Energy Price	Annual Cost	Monthly Cost
£0.20/kWh	£864	£72
£0.26/kWh	£1,123	£94
£0.30/kWh	£1,296	£108
£0.35/kWh	£1,512	£126

Comparison vs Less Efficient 4.5kW Alternative:

Energy Price	MK4 Cost	4.5kW Cost	Annual Saving
£0.26/kWh	£1,123	£1,685	£562
£0.30/kWh	£1,296	£1,944	£648
£0.35/kWh	£1,512	£2,268	£756

💰 Protection Value: If energy prices rise to £0.35/kWh (within historic volatility range), the annual saving increases to £756/year compared to less efficient alternatives.

📊 Strategic Insight: Investing in the most energy-efficient equipment now provides protection against future energy price increases, with savings growing proportionally to any price rises.

📥 Downloads & Resources

Access comprehensive technical documentation, installation guides, and product specifications:

📄 Commercial Pump Installation & Operation Manual – Complete 36-page manual covering installation procedures, electrical connections, start-up protocols, maintenance schedules, troubleshooting, and safety information for Hydrostar MK3 and MK4 commercial pumps (PDF, ~2.1MB)

📄 Hydrostar MK4 Product Leaflet – Product overview and key specifications for the Hydrostar MK4 range (PDF)

Installation Resources Included:

• Detailed wiring diagrams for three-phase connections (WYE/STAR and DELTA configurations)
• Piping installation guidelines and best practices
• Performance curves and dimensional drawings
• Electrical installation requirements and safety protocols
• Winterization procedures for seasonal installations
• Comprehensive troubleshooting guide
• Warranty terms and conditions

Key Safety Information:

• Must be installed by qualified pool/spa technician or licensed electrician
• Three-phase connection verification procedures
• Motor rotation direction checking (critical for proper operation)
• Bonding requirements per electrical codes
• Maximum pressure testing limits (35 psi)

🏆 Why Choose Parts4tubs?

✅ Genuine OEM Products – We supply only authentic Certikin commercial equipment, ensuring you receive genuine components with full manufacturer support and warranty coverage. No grey market imports or counterfeit parts.

✅ Commercial Equipment Specialists – Our team understands commercial pool operations and can provide technical guidance on equipment selection, system design considerations, and operational optimization for your specific facility requirements.

✅ Competitive Pricing on Professional Equipment – Access commercial-grade pumps at competitive rates without compromising on quality or support. We offer genuine Certikin products at prices that make equipment upgrades financially viable.

✅ Fast Delivery Across the UK – Minimize downtime with rapid dispatch of in-stock commercial equipment. We understand that pump failures require immediate response, and we prioritize rapid fulfillment for commercial customers.

✅ Technical Support Available – Questions about installation, compatibility, or operation? Our knowledgeable team can assist with technical queries and help ensure successful installation and commissioning.

✅ Comprehensive Product Documentation – All commercial pumps ship with complete installation manuals, wiring diagrams, and technical specifications to ensure proper installation and compliance with safety regulations.

✅ Commercial Warranty Support – Full manufacturer’s warranty coverage with direct support for any warranty claims or technical issues that may arise during the warranty period.

✨ Summary

The Certikin Hydrostar MK4 4.0hp (3.0kW) three-phase commercial pump represents the pinnacle of modern commercial pool pump technology, combining substantial improvements in noise reduction, energy efficiency, and hydraulic performance with robust commercial-grade construction designed for long-term reliability.

For facility managers evaluating equipment upgrades, the Hydrostar MK4 delivers compelling operational benefits: significantly quieter operation addressing noise concerns, enhanced energy efficiency providing immediate cost savings, and superior build quality reducing maintenance requirements. The three-phase motor configuration, UV-stabilized construction, and tool-free maintenance access combine to create a pump that’s not only more powerful and efficient than predecessors, but also simpler and less expensive to operate over its service life.

Whether you’re replacing aging equipment, addressing noise complaints, reducing operational costs, or specifying equipment for new installations, the Hydrostar MK4 delivers professional-grade performance with the reliability commercial operations demand. This is an investment in operational excellence that pays dividends through reduced energy consumption, lower maintenance costs, improved system performance, and protection against future energy price increases.

Invest in proven commercial technology that works as hard as you do – quieter, more efficient, and built to last.