Composting toilet
Photo by Biolet

How to troubleshoot alternative toilets

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Composting toilet problems tend to start with what the user puts into the toilet, not the hardware itself. “Service people are few and far between,” warns EcoEthic’s Rob Davis, “but most issues can be remedied over the phone or even in an e-mail.”

Something stinks and you suspect your toilet has gone anaerobic or isn’t venting properly:
• Rebalance. Good composting needs a 30:1 ratio of carbon to nitrogen. Your waste has more nitrogen (10:1 for feces; even more for urine). Adjust with the manufacturer’s prescribed additive, usually a carbon-
rich bulking agent.

• Stir or mix compost to break up and aerate the pile.  

• Stop adding anything that could kill “good” microbes, including cleaners, or anything that won’t break down quickly, such as cigarette butts or tampons.  

• Check ventilation. Fans working? Stack blockage-free, long enough (60 to 90 cm above roof peak), installed properly, and insulated? A too-short stack may allow odours to settle, and an uninsulated stack may trigger condensation and frost buildup.

• Check for excessive wetness. If your toilet has a drain, is it blocked?

• Bathroom fans, chimneys, or open windows can cause downdrafts. Rob Davis recommends using the toilet’s own ventilation system to clear shower steam. You may also need an air exchanger.
Nothing’s happening and your “finished” compost looks distressingly like its original components:

• Add moisture. Compost should be as damp as a squeezed-out sponge—about 50 per cent moisture. Stir compost, then shine a flashlight. “It should be moist enough to have a reflective glare,” says Sun-Mar sales manager Fraser Sneddon. Stir in a little warm water if needed (making sure you’ve got enough bulking agent). Cut back on fan use, which can dry out the compost.

• Add warmth. Composting bacteria stop working below about 5°C. For best results, keep the unit in a consistently warm room. Check the heating element.  

• Remove some compost. An overfilled  toilet, without enough bulking agent or stirring, tends to produce a thick, inactive mass. Check the manual for instructions for removing a portion of the compost.

• Inefficient burns require a maintenance check: With a Storburn, remove and clean the burner parts. When an Incinolet emits excessive odour, check the exhaust catalyst, which is similar to a car’s catalytic converter, and the vent, in which animals occasionally build nests.