Waimana Flow-Activated UV Unit - 33W & 48W, 25mm BSP, Whole House UV Treatment NZ

The Waimana UV unit is a standalone ultraviolet disinfection unit for whole-house water treatment, available in two sizes to match your household flow demand. The 33W model handles up to 30 LPM, suited to smaller homes and baches. The 48W model handles up to 45 LPM, suited to medium to large homes with higher simultaneous water use.

The standout feature is the flow-activated design. The UV lamp only switches on when water is moving through the chamber. When no water is flowing, the lamp powers off automatically. This means no energy is wasted between uses and water sitting in the chamber does not warm up, which can reduce UV effectiveness. It is a smarter, more efficient way to run a UV system compared to units that run the lamp continuously.

These are UV-only units. They do not include filter housings or cartridges. For UV disinfection to work reliably, incoming water must be clear. Pre-filtration should be installed upstream, with a minimum 20-micron sediment filtration. If Giardia or Cryptosporidium are a concern, 1 micron filtration is also required. If you need a complete system with filtration and UV combined, see the Waiora bundle range.

Suitable for rainwater tanks, tank water, and bore water. Bore water quality varies, so we recommend testing before installing. Get in touch if you need help choosing the right configuration.

Key Features

• Flow-activated lamp only runs when water is flowing
• 33W model: up to 30 LPM for smaller homes and baches
• 48W model: up to 45 LPM for medium to large homes
• Kills bacteria, viruses, and microbes without chemicals
• No impact on taste, smell, or water chemistry
• UV-only unit, pre-filtration required upstream
• 3-year warranty
• Fast NZ-wide delivery

Technical Specifications

• UV lamp: 33W or 48W (select from dropdown)
• UV dose: 30 mJ/cm² at rated flow
• Max flow rate: 30 L/min (33W) / 45 L/min (48W)
• Connection: 25mm BSP
• Max pressure: 116 PSI / 8 bar
• Operating temperature: 2–40°C
• Power supply: 240V
• Activation: Flow switch (auto-on when water flows, auto-off when flow stops)
• UV lamp life: Varies with usage
• Warranty: 3 years

Includes

• UV lamp
• Quartz sleeve
• Ballast
• Flow switch
• Spring
• O-rings

Does Not Include

• Filter housings or cartridges

FAQs

What's the difference between this and the Waiora bundle range?

This Waimana unit is UV-only, so it disinfects water but doesn't remove sediment or other particles on its own. The Waiora bundle range combines UV with filtration in one package, which suits customers who want a complete solution without sourcing pre-filtration separately.

What pipe size does this connect to, and will I need adaptors?

It connects via a 25mm BSP fitting. If your household plumbing runs a different size, your plumber will need the appropriate adaptors to step up or down to 25mm BSP.

Can this be installed outdoors or in an unheated space?

It's rated for operating temperatures between 2°C and 40°C, so it isn't designed for freezing conditions. If it's going in an exposed outdoor location, it needs some form of frost protection or an enclosure to stay within that range over winter.

What's included with the unit?

It comes with the UV lamp, quartz sleeve, ballast, flow switch, spring, and O-rings, everything needed for the UV chamber itself. Filter housings and cartridges for pre-filtration aren't included and need to be sourced separately.

How often does the quartz sleeve need cleaning or replacing?

The quartz sleeve should be checked periodically for mineral buildup or discolouration, since this can reduce how much UV light reaches the water. Cleaning frequency depends on water hardness and quality, and it's worth inspecting it whenever the lamp is replaced.