💦 Koller Compact Series Jet Pump – 0.55kW Single Speed

Space-saving design with powerful performance for tight installations

♨️ Product Overview

The Koller Compact Series Jet Pump (0.55kW) is specifically designed for installations where space is at a premium. Smaller in overall dimensions than the Koller Basic series and fitted with compact wet ends, this pump is ideal for fitting into tighter than normal spaces with little or no plumbing alterations required.

With a power output of 0.74HP (0.55kW) and a 2900 RPM motor, this pump delivers strong and reliable performance suitable for use as either a circulation pump or a boost pump on jet circuits with 6–8 jets. Commonly used in whirlpool baths, this model is also found in some European and Chinese hot tubs where space constraints demand a more compact solution.

Equipped with a self-drain wet end and built-in pneumatic (air) switch, the pump can be operated via air buttons or your spa’s topside control. The C-Profile mount system integrates with Koller Quick Fix Vario supports for secure, straightforward installation.

⭐ Key Features

• ✅ Compact Design – Smaller dimensions than the Basic series for tight spaces
• ✅ Motor Power: 0.55kW (0.74HP) – Reliable output for medium whirlpool baths
• ✅ Power Input (P1): 0.80kW – Efficient energy consumption
• ✅ Motor Speed: 2900 RPM – High-speed water circulation
• ✅ Single-Speed Operation – Consistent, reliable performance
• ✅ Self-Drain Wet End – Water drains automatically, preventing stagnation
• ✅ Pneumatic (Air) Switch Included – Built-in air switch for easy on/off control
• ✅ 6–8 Jet Capacity – Perfect for medium-sized whirlpool bath systems
• ✅ 1.5″ Male Buttress Threads – Industry-standard 63mm OD connections
• ✅ C-Profile Mount System – Compatible with Koller Quick Fix Vario supports
• ✅ 220–240V / 50Hz – UK-compatible electrical supply
• ✅ Bare Wire Connection – Flexible installation options
• ✅ Replaces Model 3612KEP – Direct upgrade for older installations

⚙️ Technical Specifications

Specification	Value
Brand	Koller
Series	Compact
Pump Type	Circulation / Jet
Motor Power (Output)	0.55 kW (0.74 HP)
Power Input (P1)	0.80 kW
Horsepower Range	0.55–1.0 HP
Motor Speed	2900 RPM
Speed Settings	Single Speed
Voltage	220–240V
Frequency	50 Hz
Cord / Plug Type	Bare Wire
Wet End Type	Self-Drain
Air Switch	Yes (Pneumatic)
Jet Capacity	6–8 jets
Connection Size	1.5″ Male Buttress Thread
Connection Diameter	63 mm (OD)
Thread Type	Male Buttress
Mount System	C-Profile (Quick Fix Vario compatible)
Length	300 mm
Spare Parts Available	No
Replaces Model	3612KEP
MPN	3612WEP / 3612WEP-2
SKU	PMP-3631

⚡ Electrical Requirements

Electrical Spec	Requirement
Supply Voltage	220–240V
Frequency	50 Hz
Phase	Single Phase
Power Input (P1)	0.80 kW
Motor Speed	2900 RPM
Connection Type	Bare Wire
Control Type	Pneumatic (Air) Switch

⚠️ IMPORTANT ELECTRICAL SAFETY NOTICE:

All electrical work must be carried out by a qualified electrician in accordance with UK wiring regulations (BS 7671). Hot tub and whirlpool bath installations require RCD protection (30mA) for safety. The bare wire connection requires proper termination by a qualified professional. Never attempt electrical connections yourself unless you are a qualified professional.

🔄 Compatibility Guide

Compact vs Basic Series Comparison

Feature	Compact Series	Basic Series
Overall Size	Smaller	Larger
Wet End	Compact	Standard
Space Required	Minimal	Standard
Best For	Tight spaces	Standard installations
Plumbing Changes	Usually none required	May require modifications

Connection Sizing

The Koller Compact uses industry-standard 1.5″ connections. Hot tub industry terminology differs from actual measured dimensions:

Industry Term	Actual Outside Diameter
1.5″ Connection	Approximately 63 mm
2.0″ Connection	Approximately 79 mm
2.5″ Connection	Approximately 92 mm

💡 Tip: Always measure your existing connections carefully before ordering.

This Pump Features:

• 📍 Wet End Type: Self-Drain (Compact)
• 📍 Thread Type: Male Buttress
• 📍 Connection Size: 1.5″ / 63mm OD
• 📍 Mount System: C-Profile
• 📍 Air Switch: Yes (built-in pneumatic)
• 📍 Length: 300mm (shorter than Basic series)

Self-Drain Operation

Self-drain pumps draw water via the inlet situated at the bottom of the wet end front face. When the pump is switched off, water drains back through this connection, returning to the bath and down the plug hole. This design:

• ✅ Prevents standing water in the pump
• ✅ Reduces risk of bacterial growth
• ✅ Extends pump and seal life
• ✅ Simplifies maintenance

Compatible Applications:

This pump is commonly found in:

• Whirlpool baths with limited installation space
• European-manufactured whirlpool systems
• Chinese hot tub and whirlpool bath imports
• Systems requiring pneumatic (air button) control
• Replacements for older Koller 3612KEP models

Note: Unions are sold separately. Ensure compatibility with your existing plumbing configuration before purchase.

🛠️ Installation Requirements

Mounting

Requirement	Specification
Mount System	C-Profile
Compatible Support	Koller Quick Fix Vario
Pump Length	300 mm
Base	Solid, level, vibration-dampening surface
Access	Allow adequate clearance for maintenance
Space Advantage	Fits tighter spaces than Basic series

Plumbing Connections

Connection	Size
Inlet	1.5″ / 63mm OD Male Buttress Thread
Outlet	1.5″ / 63mm OD Male Buttress Thread
Unions	Sold separately

Electrical Connection

Requirement	Specification
Connection Type	Bare Wire
Voltage	220–240V / 50Hz
Installation	By qualified electrician only

Pneumatic (Air) Switch Operation

The built-in pneumatic switch enables on/off control via:

• Air buttons mounted on the bath surround
• Topside control systems
• Electronic control systems with air switch output

Installation Notes:

⚠️ Installation must be carried out by a competent individual or tradesperson trained within the industry

⚠️ Never run the pump dry – this will cause seal damage

⚠️ Ensure proper electrical bonding to earth as per BS 7671

⚠️ Unions sold separately – ensure compatible unions are ordered

⚠️ This pump replaces model 3612KEP – check compatibility before ordering

⚠️ Little or no plumbing alterations usually required when replacing like-for-like

🔧 Maintenance Guide

Routine Maintenance

Task	Frequency	Notes
Check for leaks	Monthly	Inspect around seal area and union connections
Inspect unions	Monthly	Tighten if necessary to prevent water loss
Listen for unusual noise	Weekly	Normal operation should be quiet
Check motor ventilation	Quarterly	Keep air vents clear of debris
Test air switch operation	Monthly	Ensure pump responds to air button
Visual inspection	Monthly	Look for signs of wear or damage

Self-Drain System Care

The self-drain feature significantly reduces maintenance requirements:

• Ensure drain pathways remain clear and unobstructed
• Check that water drains completely after each use
• Inspect the inlet area periodically for debris buildup

Warning Signs – Consider Replacement If:

• ❌ Unusual grinding or screeching noises
• ❌ Water leaking from the seal area
• ❌ Motor trips the circuit breaker repeatedly
• ❌ Noticeably reduced water flow
• ❌ Motor overheating during operation
• ❌ Air switch not responding
• ❌ Excessive vibration
• ❌ Motor speed noticeably slower than 2900 RPM

🛁 Ideal Applications

Application	Suitability	Notes
♨️ Whirlpool Bath (6–8 jets)	✅ Excellent	Primary intended use
♨️ Space-Restricted Installations	✅ Excellent	Compact design advantage
♨️ Spa Circulation Pump	✅ Good	Suitable for circulation duties
♨️ Jet Boost Pump	✅ Good	Additional power for jet circuits
🛁 Whirlpool Bath Replacement	✅ Excellent	Direct replacement for Koller Compact pumps
♨️ 3612KEP Upgrade	✅ Excellent	Direct replacement model
♨️ Large Whirlpool Bath (9+ jets)	⚠️ Consider upgrade	May need higher power model

Perfect For:

• Residential whirlpool baths with limited space
• Installations where Basic series won’t fit
• European-manufactured compact whirlpool systems
• Systems requiring pneumatic control
• Replacement for existing Koller Compact pumps
• Upgrading from Koller 3612KEP models

❓ Frequently Asked Questions

Q: What is the difference between Compact and Basic series? A: The Compact series is smaller in overall dimensions (300mm vs 315mm+ length) and fitted with compact wet ends. It’s designed for tighter spaces where the Basic series may not fit, usually requiring little or no plumbing alterations.

Q: What power output does this pump have? A: The Koller Compact has a motor power output of 0.55kW (0.74HP) with a power input (P1) of 0.80kW. The motor runs at 2900 RPM.

Q: How many jets can this pump support? A: This pump is suitable for whirlpool baths with 6–8 jets.

Q: Will this pump fit my whirlpool bath? A: This pump uses 1.5″ male buttress thread connections (63mm OD) with self-drain configuration and Koller C-Profile mounting system. At 300mm length, it’s designed for tighter spaces. Measure your existing pump’s connections and available space to confirm compatibility.

Q: Does this pump replace the older 3612KEP model? A: Yes, this pump (3612WEP / 3612WEP-2) directly replaces the older 3612KEP model.

Q: Does this pump include an air switch? A: Yes, this pump has a built-in pneumatic (air) switch for on/off control via air buttons or topside control systems.

Q: What voltage does this pump require? A: The pump operates on 220–240V at 50Hz (UK standard). The pump comes with bare wire connections requiring professional termination by a qualified electrician.

Q: Is this pump single-speed or dual-speed? A: This is a single-speed pump running at 2900 RPM for consistent, reliable operation.

Q: What size are the ports? A: Both inlet and outlet are 1.5″ male buttress threads with an outside diameter of approximately 63mm.

Q: Are unions included? A: No, unions are sold separately. Ensure you order compatible unions for your plumbing configuration.

Q: Can spare parts be purchased separately? A: No, spare parts are not currently available for this pump series. If service is required, replacement of the complete unit is recommended.

Q: How do I know if my pump needs replacing? A: Signs include unusual noises (grinding, screeching), water leaking from the seal, reduced water flow, motor tripping the breaker repeatedly, air switch not responding, or overheating.

🏆 Why Choose the Koller Compact 0.55kW Pump

• ✅ Space-Saving Design – Compact dimensions for tight installations
• ✅ 2900 RPM Motor Speed – Fast, efficient water circulation
• ✅ Proven Reliability – Widely used across UK whirlpool bath installations
• ✅ Silent-Running Motor – Quiet operation ideal for residential bathrooms
• ✅ Self-Drain Technology – Prevents water stagnation and extends pump life
• ✅ Built-in Pneumatic Switch – Convenient air button control included
• ✅ Easy Installation – C-Profile mount system, usually no plumbing changes needed
• ✅ UK Electrical Compatibility – 220–240V / 50Hz supply
• ✅ Direct 3612KEP Replacement – Seamless upgrade path

🤝 Why Buy From Parts4Tubs

• ✅ UK-Based Company – Local support and fast domestic delivery
• ✅ Expert Advice – Knowledgeable team ready to assist with compatibility questions
• ✅ Fast UK Delivery – Get your replacement pump quickly to minimise downtime
• ✅ Competitive Pricing – Great value on genuine spa and whirlpool parts
• ✅ Full Warranty Support – Peace of mind with manufacturer-backed warranties
• ✅ Easy Returns – Hassle-free returns policy within 30 days
• ✅ Quality Parts Guarantee – Only genuine, high-quality components

✨ Summary

The Koller Compact Series Jet Pump (0.55kW) is a space-saving, quiet, and reliable single-speed pump designed for whirlpool baths with 6–8 jets where installation space is limited. With 0.55kW (0.74HP) output power, 2900 RPM motor speed, self-drain wet end, built-in pneumatic air switch, and industry-standard 1.5″ male buttress connections (63mm OD), this pump delivers dependable performance in a compact 300mm package. Operating on 220–240V / 50Hz UK supply with bare wire connection and C-Profile mounting, it’s the ideal choice for tight spaces and directly replaces the older 3612KEP model.