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Perfect for medium to heavy seasonal or medium residential use, the Centrex 3000 allows for both a longer composting cycle and the largest compost volume

Featuring Sun-Mar's™ patented Bio-drum™ technology, the Centrex is a true composting system that processes the compost in two stages within the unit itself.

The Centrex 3000 NE (Non Electric) - A/F (Air Flow) is a high capacity, low voltage, waterless “off-grid” alternative to the straight Centrex 3000 (heated) models. The system is designed for use in conjunction with a waterless toilet pedestal and processes waste under the bathroom floor, the non-electric system is slightly smaller than its electric counterpart.

With a larger compost capacity than the Centrex 2000 A/F NE model, the 3000 NE - A/F can comfortably accommodate up to 7 people in a holiday house situation. In a residential capacity, the compost needs to be emptied more frequently and is suitable for up to 5 people.

There is no heating unit in this model so it will operate beautifully on solar or mains power. Without the heater, the evaporation process is not as effective as in the 240-volt system. Therefore an overflow drain to a small sub-surface gravel pit is required (200x40x40cm).

A 100 mm vent and low voltage fan help to ensure that odours are dispelled with minimal electrical draw.

Capacity
Listed capacities refer to the number of people, on average, using the unit per day. Do not pick a unit that is below your capacity.

Certifications

AS/NZS 1546.2:2008 - On-site domestic wastewater treatment units - Waterless composting toilets

License Number. SMKH25591

Against the AS/NZS 1546.2

Under SAI Global

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NSF/ANSI 41 Standard - Non-Liquid Saturated Treatment Systems

This system is Certified for liquid containment, odors, and solid end products

THERE IS ONLY ONE PERFORMANCE STANDARD FOR COMPOSTING TOILETS IN NORTH AMERICA. THIS IS NATIONAL SANITATION FOUNDATION NSF/ANSI STANDARD #41. 

Sun-Mar is certified by the NSF under this stringent standard. Testing is conducted for 6 months at an NSF recognized, independent testing laboratory under a strict test protocol. 

To be certified, the unit must operate odor-free at maximum capacity (including overload conditions) and produce clean, safe compost. 

What you need to know about Composting Toilets

As additional verification, NSF obtains and tests additional compost samples from randomly selected field operations, and conducts interviews with the users of these units. For verification, please check the NSF website. 

NSF International is a not-for-profit, non-governmental organization. It is the world leader in standards development, product certification, education, and risk management for public health and safety, and for 75 years has been committed to public health, safety, and protection of the environment. 

WCTNZ® is the exclusive authorized distributor of Sun-Mar™ composting toilets in New Zealand. All Sun-Mar™ products available through WCTNZ® are guaranteed authentic, include official manufacturer warranties, and come with comprehensive local customer support—making us New Zealand’s trusted source for sustainable, waterless composting toilet solutions.

Copyright © 2025 Waterless Composting Toilets NZ Limited (WCTNZ®). All short and long product descriptions and content are the property of WCTNZ® | Waterless Composting Toilets NZ. All rights reserved.

This content has been reviewed and approved by Dylan Timney, Managing Director of WCTNZ®, who brings over 17 years of composting toilet expertise and 16 years of experience in building and eco-construction in New Zealand.

Last reviewed: June 26, 2025