AVAILABILITY: Special Order—Call to Enquire 

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 works on a continuous rotation design to maximize its capacity and improve the composting process. The rotation of the BioDrum forces the compost along the length of the Centrex 3000 and into an auto-drop mechanism, which lets the compost fall into the collection tray. Unlike with the smaller Centrex 2000, the drum doesn’t have to be rotated backward for emptying. The drum handle can continually be rotated in a clockwise direction and allow the material to work along the drum and deposit in a separate collection box.

The Centrex 3000 A/F is the waterless version of the popular Centrex range. In the A/F (AirFlow) model, the waste falls under gravity into the drum of the composter. In the case of the micro flush model the waste is transferred by the 500mL flush and multiple pedestals can be installed with one composter.

Multiple toilets are not possible with the AF model as a straight fall is required.

The Centrex 3000 A/F is a 240-volt unit as standard. The solar-compatible Centrex 3000 A/F NE version is a 12-volt (1.9-watt fan) version. See Link

The Centrex 3000 A/F is supplied with a 1" drain hose which should be connected to the 1" drain at the bottom of the unit. This drain hose ensures any excess liquids are removed to a small subsurface gravel absorption trench.

This large Centrex 3000 model will comfortably accommodate an eleven-person holiday house usage, requiring only one compost removal before and after the Holiday.

In a residential capacity, the compost will have a different maintenance interval.

ELECTRICAL RATING Maximum Amps (With Heater On) 3.6 Fan Watts (Required or Optional Hookup) 35 (Required) Heater Watts (When Thermostat switches it on) 370 Average Power Use in Watts (Heater on 1/2 time) 215
DIMENSIONS 768 x 699mm x 1803mm
FLOORSPACE REQUIRED Depth Required to Remove Drawer 1156mm Height to Bottom – Top of Waste Inlet Assembly 826mm Vent Inlet Center Distance From Rear – Left Side 959mm Waste Inlet Diameter (including flange) 250mm O/D to

The Centrex 3000 A/F features a 370-watt thermostatically controlled heater in a sealed compartment under the unit and the standard Sun-Mar 30-watt turbofan to supply oxygen to the pile, with a 2" vent stack to remove evaporating liquid and eliminate all odors.

The increased surface area in the evaporating chamber coupled with the larger heating element also provides better evaporation on electric units.

When used seasonally by up to 7-9 adults, compost will normally only need removal annually each spring. In residential use, compost will have to be extracted more frequently.

When used residentially by up to 4 adults, some compost will need to be emptied into the finishing drawer once every few months.

Capacity Notes

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.

Fixture Notes

The Sun-Mar Centrex AirFlow Systems come with Polymarble Palisade and Pandora fixtures options only. 

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

------

Sun-Mar Composting Toilet Systems are CSA certified for electrical features under CSA file number LR55925

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