Biolet XL


For those who need extra capacity, the BioLet XL is the right choice. Equipped with the same automatic features as the BioLet Deluxe, the BioLet XL has a 40% larger composting chamber and an extra heating element in the bottom to help evaporate the excess liquids, all within an attractive body of durable, polished ABS plastic. Additionally, the BioLet XL is equipped with 3 mixing arms equipped with "cutting blades" to help break-down toilet paper and keep the product in an airy, homogenous state, and a float switch that operates the heaters when excess liquid is detected. These features make the BioLet XL our most advanced composting toilet and sets the standard for composting toilets around the world. Tested and approved by the National Sanitation Foundation, the BioLet XL was proven to be the safest composting toilet on the market and exceeded all requirements by a wide margin. Its design has been voted the most user-friendly of all high capacity composting toilets. As is true of all BioLet models, the XL is equipped with a compost cover that hides the material from view and opens automatically when sitting - another feature engineered exclusively by BioLet and with a seat height of only 19.5", the BioLet XL is very comfortable to use and it has no awkward footstool to hamper children and the elderly. If the best is desired and a high capacity composting toilet is needed, the BioLet XL is the right choice! 

BioLet XL is an on-site, self contained, biological toilet, where human waste (feces, urine and toilet paper) are collected, excess liquid is evaporated and solid material is decomposed to a soil-like, hygienically safe product (humus) without producing an unpleasant odor.

BioLet XL needs no water, nor chemicals, and there is no waste water discharge from the unit necessitating a connection to a sewer or septic tank. The BioLet XL utilizes the natural process of aerobic decomposition and is designed to maintain a warm and humid environment inside the unit, encouraging biological degradation of the waste through the scavenging action of the aerobes.

Within a relatively short period of time, human waste and toilet paper are efficiently transformed into a small amount of fertile compost. The BioLet XL reduces the volume of the waste entering the toilet by approximately 90%, leaving only 10% of an end-product, which can be recycled back to nature in a safe way, and without polluting the environment.

BioLet XL is tested and approved under NSF-Standard 41, for residential use by a family of four and is designed to handle occasional overloads.

Performance Data: (from the NSF-Standard 41 test and approved for listing) in regard to Liquid containment, Odor and Fecal Coliform:

Liquid Containment   no leakage no liquid escape evident
Odor Bowl non objectionable no offensive odor
  Vent non objectionable no offensive odor
Fecal Coliform (No/Gm) in final end product <= 200 MPN/gm 3 MPN/gm


AIR FLOW   Air flow through typical BioLet Toilet

There is a constant flow of air in through the seats of our units and out through the vent pipe. This air flow serves 3 purposes:

Recirculate air through the system to provide additional oxygen to the aerobic bacteria to accelerate the decomposition process.
Assist in the evaporation of the excess liquids and expel them to the atmosphere through the vent pipe.
Draw odors from the unit and expel them to the atmosphere.


A. Ventilation outlet
B. Fan motor/fan blade
C. High temperature limit switch
D. Heating element
1. Phillips screws (top/lower unit)
2. Warm air channels
3. Compost chamber
4. Grate
5. Humus tray
6. Adjustable thermostat
7. Liquid level switch
8. Microswitch9. Mixer motor assembly
10. Shear Pin
11. Compost cover
12. Air return channel
13. Mixer arm
       a. leveling
       b. raking
       c. stationary
14. Front cover for humus tray
15. Fluid level indicator (emptying)
16. Fluid level indicator (humus tray)
17. Bottom heating element
18. Terminal block


The BioLet XL is easy to install!

Fasten the BioLet XL to the wall.

Make a hole in the ceiling and roof for the ventilation pipe.

Push the outer pipe into the roof flashing and seal it carefully.

Empty the bag of compost starter into the BioLet.

Plug into grounded outlet.

The BioLet XL is ready to be used.





  • 4 people - full-time use
  • 6 people part-time use

Electrical Specifications:

  • Total - 370 Watts
  • Average continuous consumption over 24 hr period - 65 Watts
  • Heaters (thermostatically controlled) - 305 Watts
  • Fan motor - 25 Watts
  • Mixer Motor - 40 Watts

Weight Limit: 350 lb

Required Room Temperature: 64F during periods while the toilet is in use.

Measurements and Weight:


Shipping Installed
Depth 35" 32"
Width 26" 25"
Height 29" 26"
Seat Height 19.5" 19.5"
Additional depth to remove tray --- 28"
Weight including vent kit and initial starter mulch 90 lb 80 lb

Material: Completely sealed casing of ABS - plastic. Mixing arms and other important metal components of stainless steel.

Warranty: Life-time limited warranty on body, Three year limited warranty on remaining parts.

BioLet Box Includes:
1 - Composting toilet
1 - Wall bracket
2 - Wood Screws
1 - Starter mulch
1 - Winterizing plug
1 - Emptying frame
1 - Manual mixing rake
5 - 2' sections 54mm 
white vent, belled 1 end
1 - 2' section 54mm white vent pipe, no bell
1 - 2' section 108mm black vent pipe, belled 1 end
1 - 2' section 108mm black vent pipe, no bell
4' - Styrofoam insulation
1 - 108mm X 54mm reducing coupling
1 - Roof flashing
1 - Instruction video


Toilets (click below)

Residential Cabin
4 people 6 people
3 people 4 people
3 people 4 people
2 people 3 people
4 - 6 people 4 - 6 people