Central Composting Toilet Systems
Use Only One Pint Per Flush

For those that want a traditional type of toilet with water flush in the bathroom, the Centrex family low water flush systems are ideal.

Centrex low water flush systems are designed for use with a Sealand 1 pint flush toilet. The Sealand toilet in the bathroom is connected by a standard 3" plumbing pipe to the composting unit which is below the toilet and normally within 15-20 feet horizontally.

Selecting The Right Unit

Selection of the correct system will be based on whether or not there is a continuous supply of 110 volt electricity, if the unit is to be used seasonally or residentially, and how many people will be using the unit.

Electric or Non-electric

If you have continuous 110 volt power, I suggest an electric unit. Electric units feature a 370 Watt 120 volt thermostatically controlled heater in a sealed compartment beneath the composting chamber. Odor free operation is maintained by a standard 30 Watt turbo fan directing air up a 2" vent stack.

If you have no electricity, then a non-electric (NE) unit is what you need. 12 volt fans are supplied with Centrex 2000 and Centrex 3000 series non-electric units but are not normally needed for cottage applications, unless the system is used heavily or is particularly subject to downdraft.

AC/DC units are dual vented units with both a 2" and 4" vent for those who expect to have 110v power in the future, or are running a generator for 12 or more hours per day.

Unit Capacity

Three sizes of central units are available: the Centrex 1000 (batch unit), Centrex 2000 ( batch unit) and Centrex 3000 (continuous flow unit) are available for use with 1 pint flush toilets. The selection should be based on whether the unit is used seasonally or residentially, and the number of people that will be using the unit.

Typically, the Centrex 1000 is suitable for light to medium cottage use, the Centrex 2000 for medium to heavy cottage use or light residential use, while the continuous flow Centrex 3000 series is suitable for very heavy cottage use, or medium residential use.

All central low flush systems are supplied with a 1" drain hose which should be connected to the 1" drain at the bottom left of the unit. Liquid output should be collected or drained into an approved facility. Please click here for more information on handling excess liquid.

NOTE: Advertised composting capacities can be doubled for short periods as often as once a month.

Specifications and Rough-in Dimensions

Click here for specifications and rough-in dimensions.

Centrex 1000

The Centrex 1000 model is ideal for those who have electricity and want a unit for a light seasonal application.

In light to medium seasonal use the Centrex 1000 is typically able to hold compost for the full season, and compost needs extraction only in the spring.

The Centrex 1000 features a 260 watt heater in a sealed compartment under the unit and the standard Sun-Mar 25 watt turbo fan and 2" vent stack to ensure odorless operation.

All 1000 series units are supplied with a 1" drain hose which should be connected to the 1" drain at the bottom left of the unit. Please click here for more information on handling excess liquid.

The 1000 series is designed for use with Sealand low flush toilets (purchased separately).

Composting Capacity: 5-7 people Weekend/Vacation Use only.

Voltage: 110

Centrex 1000 NE (Non-electric)

The Centrex 1000 NE was recently re-engineered for better compost flow to include input doors on the left and an output door on the right. This output door is only open when the drum is rotated backwards to extract compost.

Other changes include a larger finishing drawer, easier access for maintenance, and a redesigned access port which is secured by a catch.

In light to medium seasonal use the Centrex 1000 is typically able to hold compost for the full season, and compost needs extraction only in the spring.

The Centrex 1000 NE does not normally need a 12 Volt fan for the 4" vent stack, but a 1.4 Watt fan is available if required. If a bend needs to be installed in the vent stack, a 12 Volt fan is required).

All 1000 series units are supplied with a 1" drain hose which should be connected to the 1" drain at the bottom left of the unit. Please click here for more information on handling excess liquid.

The 1000 series is designed for use with Sealand low flush toilets (purchased separately).

Composting Capacity: 4-6 people weekend/vacation use

Voltage: N/A

Centrex 1000 AC/DC

The Centrex 1000 AC/DC is a hybrid power unit meant for light seasonal applications where the availability of AC power is uncertain. Employing a dual vent stack, the 1000 AC/DC is vented passively in the event of a power outage, or can be used solely on a non-electric basis until 110v power is put in.

You can choose to hook up both or just one of the vents, depending on your power situation.

In light to medium seasonal use the Centrex 1000 AC/DC is typically able to hold compost for the full season, and compost needs extraction only in the spring.

The Centrex 1000 AC/DC features a 250 Watt heater in a sealed compartment under the unit and the standard Sun-Mar 30 Watt turbo fan and 2" vent stack to ensure odorless operation. It also features a 4" vent stack which is meant to passively vent the unit when non-electric operation is required.

This unit is ideal for those who do not have power now but are expecting it in the future, or for those who have generators that can only run part-time.

All Centrex 1000 series units are supplied with a 1" drain hose which should be connected to the 1" drain at the bottom left of the unit. Please click here for more information on handling excess liquid.

The Centrex 1000 series is designed for use with Sealand low flush toilets (purchased separately).

Composting Capacity:

In AC Mode: 5-7 people weekend/vacation use
Voltage: 110

In DC (Non-electric) Mode: 4-6 people weekend/vacation use
Voltage: N/A, Optional 12 Volt Fan

Centrex 2000

Perfect for medium to heavy seasonal or light residential use, the Centrex 2000 allows for both a longer composting cycle, and larger waste volumes than the 1000 models. 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 removing 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.

The Centrex 2000 features a 370 Watt thermostatically controlled heater in a sealed compartment under the unit and the standard Sun-Mar 30 Watt turbo fan, with a 2" vent stack to remove evaporating liquid and fresh odors.

The Centrex 2000 is supplied with a 1" drain hose which should be connected to the 1" drain at the bottom of the unit. Please click here for more information on handling excess liquid.

The Centrex 2000 may be used with one or more Sealand low flush toilets, purchased separately.

Composting Capacity: 4-6 Residential Use, 7-9 Vacation Use

Voltage: 110

Centrex 2000 NE (Non-electric)

Perfect for medium to heavy seasonal use or light residential use, the Centrex 2000 NE allows for both a longer composting cycle, and larger waste volumes than the 1000 NE.

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

The Centrex 2000 NE (Non-electric) is the non-electric version of the Centrex 2000 and is fitted with a 4" vent stack. Installation of a 12 Volt fan is optional, but it is recommended for heavy seasonal or residential use, or where the installation is particularly subject to downdraft, being surrounded by high trees or hills. We also recommend the fan if you need to install a bend in your vent stack.

2000 series units are supplied with a 1" drain hose which should be connected to the 1" drain at the bottom of the unit. Please click here for more information on handling excess liquid.

The Centrex 2000 NE may be used with one or more Sealand low flush toilets, purchased separately.

Composting Capacity:3-5 Residential Use, 6-8 Vacation Use

Voltage: N/A

Centrex 2000 AC/DC

Perfect for medium to heavy seasonal or light residential use, the Centrex 2000 AC/DC allows for both a longer composting cycle, and larger waste volumes than the Centrex 1000 AC/DC. The increased surface area in the evaporation chamber coupled with the larger heating element also provides better evaporation on electric units.

When used seasonally by 7-9 adults, compost will normally only need removing 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.

The Centrex 2000 AC/DC features a 370 Watt thermostatically controlled heater in a sealed compartment under the unit and the standard Sun-Mar 30 Watt turbo fan, with a 2" vent stack to remove the evaporate and fresh odors. This may be used when the unit is in AC operation.

For easy switching between AC and DC mode, the Centrex 2000 AC/DC requires that 2 vent stacks be installed to handle the separate venting functions. The 2" vent is in use when the AC fan is in operation, and the 4" vent is venting the unit passively when there is no power available.

As an extra option, we include a 12 Volt 1.4 Watt fan with the Centrex 2000 AC/DC. You may want to install this fan if the unit is to see maximum capacity use, and you should install the 12 Volt fan if you have to put any bends in the 4" vent stack, as you will then lose the "chimney effect" advantage of a vertical stack, and will need to provide air movement with the fan.

You may just install one vent if you plan on using only one function. If, for example, you do not have 110v AC power yet but anticipate getting it in the future, you can install just the 4" vent and leave the 2" vent capped off.

The Centrex 2000 AC/DC is supplied with a 1" drain hose which should be connected to the 1" drain at the bottom of the unit. Please click here for more information on handling excess liquid.

The Centrex 2000 AC/DC may be used with one or more Sealand low flush toilets, purchased separately.

Composting Capacity:

In AC Mode: 4-6 Residential Use, 7-9 Vacation Use
Voltage: 110

In DC (Non-electric) Mode: 3-5 Residential Use, 6-8 Vacation Use
Voltage: N/A, Optional 12 Volt Fan

Centrex 3000

The Centrex 3000 utilizes a continuous flow design for very heavy cottage use or medium residential use. With a continuous flow system, rotation of the drum moves compost along the larger and longer 3000 series drum, before it drops automatically into the collection housing at the end of the unit. Under normal operating conditions the drum will not have to be turned backwards for emptying.

All Centrex 3000 electric units feature a 370 Watt 120 volt thermostatically controlled heater in a sealed compartment beneath the unit coupled with the standard Sun-Mar 30 Watt turbo fan and 2" vent stack. This heater assists in evaporation of liquids, reducing the amount of effluent from the unit. The fan also removes any fresh odors from the unit, ensuring odor-free operation.

All Centrex 3000 series units are supplied with a 1" drain hose which should be connected to the 1" drain at the bottom left of the unit. Please click here for more information on handling excess liquid.

This unit is for use with a Sealand low flush toilet, purchased separately. More than one toilet may be installed on this system, as shown in the picture.

Composting Capacity: 6-8 Residential Use, 9-11 Vacation Use
Voltage: 110

Centrex 3000 NE

The Centrex 3000 NE (Non-Electric) employs a continuous flow design for very heavy cottage or medium residential use. With a continuous flow system, rotation of the drum moves compost along the larger and longer 3000 series drum, before it drops automatically into the collection housing at the end of the unit. Under normal operating conditions the drum will not have to be turned backwards for emptying.

When used seasonally by up to 10 adults, compost will normally only need to be removed from the collection chamber annually at the beginning of the season.

The Centrex 3000 NE features a 4" vent stack which vents the unit passively. Included is an optional 12 volt fan that we recommend installing in the vent stack, especially if you need to put a bend in the vent as shown above.

No electricity is required to operate this unit, except for the optional 12 volt fan. All Centrex 3000 series units are supplied with a 1" drain hose which should be connected to the 1" drain at the bottom left of the unit. Please click here for more information on handling excess liquid.

This unit is for use with one or more Sealand low flush toilets, purchased separately.

Composting Capacity: 5-7 Residential Use, 8-10 Vacation Use
Voltage: N/A

Centrex 3000 AC/DC

The Centrex 3000 AC/DC composting toilet system is a continuous "auto-flow" design for very heavy cottage use or medium residential use. With a continuous flow system, rotation of the drum moves compost along the larger and longer Centrex 3000 series drum, before it drops automatically into the collection housing at the end of the unit. Under normal operating conditions the drum will not have to be turned backwards for emptying.

When used seasonally by up to 8 or 9 adults, compost will normally only need to be removed annually at the beginning of the cottage season.

The Centrex 3000 AC/DC features a 370 Watt 120 volt thermostatically controlled heater in a sealed compartment beneath the unit coupled with the standard Sun-Mar 30 Watt turbo fan and 2" vent stack. The heating system reduces the amount of effluent from the unit, and the fan removes any fresh odors, ensuring odor-free operation.

The Centrex 3000 AC/DC also features a 4" vent stack which vents the unit when no electricity is present. Included is a 2.4 Watt 12 volt fan that we strongly suggest installing in the 4" vent stack, especially if you need to put a bend in the vent as shown in the diagram.

All 3000 series units are supplied with a 1" drain hose which should be connected to the 1" drain at the bottom left of the unit. Please click here for more information on handling excess liquid.

This unit is for use with one or more Sealand low flush toilets, purchased separately.

Composting Capacity:

In AC Mode: 7-8 Residential Use, 10-12 Vacation Use
Voltage: 110

In DC (Non-electric) Mode: 5-6 Residential Use, 8-10 Vacation Use
Voltage: N/A, Optional 12 Volt Fan