Coming Soon - BWT i-Star II Pool & Spa Pump - Single Speed & Variable Speed - 0.4HP to 2.0HP

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Model

i-Star II 8 - 0.4HP Single Speed i-Star II 11 - 0.5HP Single Speed i-Star II 15 - 0.75HP Single Speed i-Star II 19 - 1.0HP Single Speed i-Star II 25 - 1.5HP Single Speed i-Star II 30 - 2.0HP Single Speed i-Star II VS - 1.0HP Variable Speed

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BWT i-Star II Pool & Spa Pump - Single Speed & Variable Speed

Hard-wearing, quiet and economical filtration pumps. Salt compatible, self-priming to 1.5m, 50mm ports, backed by a 3 year warranty.

Physically Stocked, unlike most "drop-shipping" websites.
Shipped from VIC, NSW, QLD, WA

The BWT i-Star II range is built for reliable everyday circulation. A large-capacity pre-filter and transparent threaded lid make basket checks quick, the fibreglass-reinforced polypropylene body resists corrosion in salt and mineral pools, and a low-friction volute design keeps noise down.

The standout feature is the protected shaft-seal design - the mechanical seal is mounted on a synthetic resin protective shaft, so the motor shaft never contacts pool water. Available from 0.4HP through to 2.0HP in single speed, plus a 1.0HP variable speed model with three programmable constant speeds.

Key Features

Corrosion resistant - pump body and pre-filter in fibreglass-reinforced polypropylene, fully resistant to salt electrolysis
Protected mechanical seal - motor shaft is isolated from pool water by a synthetic resin shaft sleeve
Quiet operation - large pre-filter and next-generation volute using low-friction materials
Large capacity pre-filter - approx. 3L strainer tank with a transparent, externally threaded lid
Self-priming up to 1.5m
50mm inlet and outlet ports with glue sockets and barrel union nuts
Salt chlorination compatible
Three programmable constant speeds on the variable speed model
Stainless steel fasteners throughout

Models & Technical Data

Model	Item Number	Power	Rated Amps	P1 kW	P2 kW	Flow @ 80 kPa (L/min)	Noise @ 1m (dBA)	Ports
i-Star II 8	BWTISTAR8	0.4 HP	2.60	0.60	0.30	140	57.6	50mm / 50mm
i-Star II 11	BWTISTAR11	0.5 HP	3.30	0.69	0.45	180	57.3	50mm / 50mm
i-Star II 15	BWTISTAR15	0.75 HP	4.70	1.02	0.65	240	58.0	50mm / 50mm
i-Star II 19	BWTISTAR19	1.0 HP	5.30	1.17	0.75	320	63.4	50mm / 50mm
i-Star II 25	BWTISTAR25	1.5 HP	6.40	1.65	1.10	410	65.6	50mm / 50mm
i-Star II 30	BWTISTAR30	2.0 HP	7.40	1.88	1.50	510	65.1	50mm / 50mm
i-Star II VS	BWTISTARVS	1.0 HP Variable Speed	5.30	1.17	0.75	320	63.4	50mm / 50mm

General Specifications

Inlet and outlet ports: 50mm
Self-priming: up to 1.5m
Strainer tank capacity: approx. 3L
Strainer basket mesh: approx. 3.2 x 2.6mm
Lid: transparent, threaded around the exterior
Compatible with salt chlorination
Available in single and variable speed

Materials of Construction

Pump casing: glass-fibre reinforced polypropylene (PP GF 30)
Intermediate housing: PP GF 30
Gland housing: PP TV 40
Diffuser: A 6 GF 15
Impeller: PA 66 GF 30
Strainer basket: polypropylene
Lid: transparent polycarbonate with PP GF 30 threaded ring
Mechanical seal: carbon / ceramic / NBR
Unions and glue sockets: ABS
Elastomers: NBR
Screws: stainless steel

Warranty

3 years parts
1 year labour
1 year mechanical seal

Sizing Guidance

As a general rule, a filtration pump should turn over the full pool volume at least twice per day, with a minimum of 8 hours daily run time. Larger pools, warmer water and heavier bather loads all call for longer run times or a higher output model. Where a variable speed pump is fitted, low-speed running for the bulk of the cycle with a short high-speed period will usually deliver the same turnover at a fraction of the energy cost.

Note that pump selection also depends on your filter's maximum flow rate, pipe sizing and total head. Oversizing a pump against an undersized filter or narrow pipework wastes energy and can shorten equipment life.

Note: Electrical connection must be carried out by a licensed electrician in accordance with local requirements. We carry more spare parts than anyone.

Manufacturer Brochures, Manuals & Part Numbers

Need exploded views, spare part numbers, pump curves, dimensions or more product information? See the manufacturer documents: i-Star II Brochure | i-Star II Data Sheet & Parts List | i-Star II VS Data Sheet

To the layperson, plumbing sizes and their names can be confusing due to the nominal sizes and naming conventions used.

This is not something we made up. Plumbers and manufacturers have used nominal (meaning ‘by name only’) sizing for decades.

Simply put, in plumbing, named sizes are often not the actual measurements of the pipe, fitting, or part. A PVC pipe called “50mm” or “2"” does not measure 50 mm anywhere. Instead, it follows nominal sizing, an internationally-standardised naming system.

Almost all fittings we use in the pool & spa industry use “pressure PVC” pipe & fittings. Do not confuse with “DWV” or other pipe & fittings and their names and sizes.

Use the Outside Diameter (OD) to check your pipe against fittings. Below is a quick reference for common spa & pool pipe sizes:

Imperial Name	Metric Name	Pipe Diameter (OD)
1/2"	15mm	~21.2–21.5 mm
3/4"	20mm	~26.6–26.9 mm
1"	25 mm	~33.4–33.7 mm
1.5"	40 mm	~48.1–48.4 mm
2"	50 mm	~60.2–60.8 mm
2.5"	65 mm	~75.2–75.5 mm

To reiterate, these are nominal sizes and are designed to fit matching fittings — not to measure what their name suggests. These are based on PVC Pressure Pipe AS/NZ 1477 Dimensions^1.

º Internal diameters vary slightly by manufacturer and class.
¹ Not all pool/spa fittings match these dimensions exactly. Some do not follow Australian or international standards. Chinese spas may use proprietary fittings.

Understanding Plumbing Sizes & Nominal Measurements

Plumbing sizes can be confusing. PVC and many other pipe systems use nominal sizes—the size is a name, not the exact measured dimension. This convention is used across most pool and spa systems and other plumbing areas so that pipes and fittings remain compatible.

Quick example: A 2" / 50 mm fitting is named for the pipe it connects to, but the pipe’s actual outside diameter (OD) is approx. 60.3 mm (typically ~60.2–60.5 mm in AS/NZ pressure pipe).

Another example: a 2” / 50mm o-ring may refer to a barrel union, etc that suits 50mm pipe. Eg: a “50mm Balboa Gasket” refers to a heater gasket that measure 74mm across, but suits a Balboa barrel union made for 50mm pipe (and the 50mm pipe does not measure 50mm either!)

Why pipe sizes don’t match the measurements

The Nominal Pipe Size (NPS) system standardises pipe dimensions so that pipes, fittings, valves, and accessories interoperate.

Plumbers work with these nominal names every day, but DIYers can be tripped up if they try to match by a tape-measure alone.

How to Measure Pipe Correctly

Pipe size is identified by:
- The pipe’s Outside Diameter (OD).
- The fitting’s Inside Diameter (ID) (socket opening).
Pipe Class / Schedule (e.g., Class 9, 12, 18 or Sch 40) relates to wall thickness and therefore the Internal Diameter (ID) and pressure rating.
The outside diameter of a fitting is not useful (wall thickness varies by manufacturer).

Important: For pool/spa work, most plumbing uses Pressure Pipe (AS/NZ standards) — not DWV. Always check OD and the pipe class against your equipment specifications.

Hose & Tube Dimensions

Common flexible hose sizes used in pool/spa systems (approximate IDs).

Imperial Name	Metric Name	Inside Diameter (ID)
3/8"	9–10 mm	~9 mm
3/4"	19 mm	~19 mm

BSP – British Standard Pipe Thread Sizes

BSP thread names are also nominal. The thread OD will not equal the nominal name.

BSP Thread Size Naming	Outside Diameter (mm / inch)	TPI
1/16" BSP	7.7 mm / 0.304"	28
1/8" BSP	9.7 mm / 0.383"	28
1/4" BSP	13.16 mm / 0.518"	19
3/8" BSP	16.66 mm / 0.656"	19
1/2" BSP / 15 mm	20.99 mm / 0.825"	14
5/8" BSP	22.99 mm / 0.902"	14
3/4" BSP / 20 mm	26.44 mm / 1.041"	14
7/8" BSP	30.20 mm / 1.189"	14
1" BSP / 25 mm	33.25 mm / 1.309"	11
1-1/4" BSP	41.91 mm / 1.650"	11
1-1/2" BSP / 40 mm	47.80 mm / 1.882"	11
2" BSP / 50 mm	59.61 mm / 2.347"	11
2-1/4" BSP	65.71 mm / 2.587"	11
2-1/2" BSP	75.18 mm / 2.960"	11
3" BSP	87.88 mm / 3.460"	11
4" BSP	113.03 mm / 4.450"	11
5" BSP	138.43 mm / 5.450"	11
6" BSP	163.83 mm / 6.450"	11

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BWTISTAR8

Important Information

Delivery Pricing & Options

*Free Road Shipping on orders over $149.00 Australia-wide
Capped Road Freight Shipping at $19.95
Express Post available on many products. Contact us before ordering if urgent.
Shipping to Australia & New Zealand Only
Shipping Policy & Info
About Us

Heater & Spa Parts is built on decades of real pool and spa industry experience, from manufacturer R&D and consulting to in-field spa repairs, pool heater servicing, trade support and diagnostics.
We understand how the equipment works, why it fails, and why it should be replaced.
More Parts than Anyone

We are a real Australian store with real stock, not a drop shipper.
With 100,000+ parts across 10,000+ product lines, we stock spa parts, pool heater parts, filters, pumps, jets, chemicals, touchpads, control panels, manuals and more, backed by fast dispatch and practical advice.
Pick-Ups

Pickup for many items is available from our Carrum Downs, VIC store at 10 Industry Blvd, Carrum Downs.
If pick-up is urgent, contact us before ordering.
Our NSW, QLD and WA warehouses currently ship orders only, with no retail counter available yet.

Brand Information

We are an authorised dealer, retailer, and/or service & warranty agent for many leading brands, including: Fluidra (AstralPool, Zodiac, Hurlcon), Aeware, Air Supply of the Future, Aqua-Flo, Balboa, Celsior, CG Air, CMP, Custom Moulded Products (CMP), Darlly, Davey, Del Ozone, Dontek, Edgetec, Emaux, Filtrite, Gecko, Goulds, Harwil, Henden, Herga, Honeywell, HydroAir, HydroQuip, ITT, Jandy, Joyonway, Laing, Len Gordon, Lo-Chlor, LX, LX Whirlpool, Magic Plastics, Magnum, Monarch, Onga, Pentair, PoolSystems, Presair, Raypak, Reemay, Rheem, Rising Dragon, S&P, Sensaheat, Spa-Craft, Spa-King, SpaNet, Spa-Quip, SpaTex, SpaZazz, Tecmark, Therm Products, Thermcore, Waterco, Waterway, Weld-On, Whirlpool, Xylem, and others.

We also sell parts for many spa and swim spa brands, including parts to suit Alpine Spas, Artesian Spas, AquaPulse Spas, Balboa spas, Bullfrog Spas, Caldera Spas, Canadian Spa Company, Cedar Spas, Chinese import spas, Coast Spas, Costco spas, Cyclone Spas, Davey spas, Decina, Designer Spas, Dimension One Spas, eBay spas, Endless® Spas, Fastlane Pools, Fisher Spas, Gecko spas, Halo Spas, H2O Spas, H20 Spas, Heritage Spas, HotSpring Spas, HydroQuip spas, Impact Spas, Jacuzzi, Just Spas, Just Swim Spas, LA Spas, Lanark Spas, Leisurite Spas, Maax Spas, Monarch Spas, MySpa, O2 Spas, Oasis, Sapphire Spas, Sapphire Swim Spas, SCS Spas, Signature Spas, Silver Spas, Spa Industries, Spa-Quip spas, SpaNet spas, Spas Direct, Sundance Spas, Sunrans, SwimEx, Trueform Spas, Tuff Spas, Urban Pool, Vortex®, Vortex® Swim Spas, and many others.

Handy PVC Plumbing Size Info
Plumbing sizes can be confusing. Pressure PVC pipe use nominal sizes - the size is simple a name, not the measured dimension. This convention is used across most pool and spa systems so that pipes and fittings remain compatible.
- 50mm / 2" = ~60-61mm OD
- 40mm / 1.5" = ~48mm OD
- 25mm / 1" = ~33-34mm OD

Plug Types & Styles
Common plug types found on spa equipment are AMP, Mini JJ, C38 (Aus 3-pin), Gecko in.link, etc.
To view plug types, click here.
- AMP plugs are the most common type used for over 20 years.
- Almost all Mini J&J plugs are no longer available and must be modified.
- C38 is the common Australian 3-pin plug found in normal household outlets.
- Gecko (Aeware) in.link style plugs are no longer available and must be modified.

General Information & Disclaimers

Many products we supply are OEM-supplied and may not include retail packaging, printed instructions, or accessories. Refer to the product listing for details, or contact us if unsure.

Product images are for illustration only. Actual items may vary due to manufacturer changes, updates, and other variations. Images may show a full assembly, a partial assembly, or a specific component only. They are provided for identification purposes and do not by themselves define what is included. Please read the title and description carefully.

All products must be installed and used by qualified and experienced persons in accordance with applicable Australian standards and manufacturer requirements. We are a parts supplier, similar to an electrical, plumbing, or automotive parts supplier. We sell parts, but cannot always provide exact installation, troubleshooting, or system design advice. Buyers are expected to know what they are doing or use a qualified professional.

® Trademark Information

All trademarks, brand names, and logos displayed on this website are the property of their respective owners. Heater & Spa Parts is an independent Australian supplier of replacement parts and accessories. Use of trademarked names, logos, and brands is for identification and compatibility purposes only, unless otherwise stated.