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          How to Troubleshoot a Composting Toilet Generating Odour

          How to Troubleshoot a Composting Toilet Generating Odour

          As we know, composting toilets are designed to be odourless. A well-designed and properly maintained toilet shouldn't have any unpleasant odours. If it does, something is wrong. Here are a few reasons as to why a composting toilet may start to generate odour, and ways to fix it.

          Exhaust fan has stopped working

          Every composting toilet has an electrical exhaust fan. In addition to aerating the compost pile and aiding evaporation of liquids, this is what keeps the system odourless. If the fan goes, smells start creeping in. 

          • Make sure to keep up with your fan's maintenance, giving it a yearly clean 
          • Have a spare on hand, in case you need to replace it
          • Equip the set-up with a wind-driven vent as a backup for fan failure and power-outages

          The compost pile is too wet

          If the compost pile becomes too wet, the composting process can turn from aerobic to anaerobic, producing significantly more smell. This is usually caused by poor drainage or insufficient amount of bulking agent additive. 

          • Always follow the manufacturer's guidelines in regard to addition of bulking agent - use the right stuff, in the right amount
          • Fix a wet pile with these simple steps:
          1. Add 1-2L of BBL Tamper Spray concentrate to the pile. While adding liquid to a wet pile may seem counterproductive, this takes the pile out of an acidic condition, and reintroduces composting microorganisms into it
          2. Add a layer of Compost Black
          3. Add a layer of bulking agent (wood shavings/coco peat/peat moss/garden waste - dried brown matter)
          4. If your system has a mixing mechanism, mix the pile. Otherwise, leave layers in place
          5. Keep using the toilet
          6. Increase amount of bulking agent used when using the loo, compared to amount used previously
          7. Use Nature Flush Enzymes daily to maintain the enzymatic balance of the compost
          8. Make sure your fan is performing at maximum capacity

          Harsh chemicals or soaps have killed the compost

          Never use harsh chemicals, homemade baking soda cleaning solutions or soaps to clean your composting toilet. Even eco soaps are a no-no. All of these are designed to kill bacteria and, while this is usually a good thing, unfortunately they do kill good composting bacteria, too, which are necessary for a healthy pile.

          The compost has been exposed to extreme temperatures/has dried out

          Extreme temperatures can dry out a compost, killing off good bacteria and microbes necessary for an active and healthy pile to thrive. This is unlikely to happen in NZ temperatures, but what can happen is a pile can dry out if the toilet is not used for a long period.


          Need help choosing a system? Call WCTNZ® on 0800 022 027 for free advice on system specification and setup. Advanced design consultancy services are also available.

          WCTNZ® | Waterless Composting Toilets NZ Limited | Copyright 2022 ©

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