Using your Sun-Mar composting toilet in winter

When cottage season winds down and people start preparing for winter, our sales and service departments are frequently asked, “Can my Sun-Mar toilet be used over the winter?”

The short answer is yes, all of our toilets can be used in the winter.

With toilets installed across North America, this is an important question for new and occasional users to Sun-Mar toilets. Our self-contained toilets, such as the GTG, the Excel and the Compact, and our Central systems like the CENTREX 2000 or CENTREX 3000, can be easily used in the winter, usually with only minimal changes to how they are installed.

With winter comes the cold weather, and changes in temperature can affect your compost in strange ways. For example, if the self-contained or CENTREX series toilet is installed in a location with temperatures consistently below 50° F / 15° C, the compost in the drum will go dormant and composting will stop. This will cause the toilet to function as a holding tank until the spring thaw comes.

If your toilet will be used heavily in the winter, there are a few more steps to making sure your toilet functions properly. Things like insulating certain components, installing a heat source near the composter, and removing compost from the drum to make room for new material will keep your composter in top condition.

No two installations are identical, but with proper consideration, your toilet can continue to function all year-round. Our customer service department is always happy to go over your particular installation, and advise how best to proceed for a hassle-free transition into the colder months ahead.

Information on winter use and other matters can be found in your owner’s manual, by contacting our customer service department at 1.888.341.0782, option 4, via email at or on our website at (the information on this page can be printed or saved for future reference).

use your sun-mar in fall and relax

**Please note: The information in this post is not intended to replace your owner’s manual. As each installation is different, if you have any questions, our customer service department is more than happy to help, and can be reached at 1.888.341.0782, option 4, or via email at **