Sun-Mar units serve as a reliable year-round facility when prepared for continuous or periodic use during the cold winter months. All units are made of fiberglass and marine grade stainless steel; so even if the compost freezes in the drum, sub-zero temperatures will cause no damage.

Winterizing Your Sealand Toilet

While the composting system will not suffer any damage due to freezing, a particular part on the Sealand low flush toilet will. This part is the water valve. You will of course not need to do this if you are keeping the bathroom heated throughout the winter. For best results, do one of the following:

  • Take off the water valve and bring it back with you, keeping it in a heated space during the cold winter months. To do this, remove the pedal cover, and then remove the valve. The toilet may be flushed with a pail of water during limited winter use.

  • Remove the brass nut on the end of the water valve. While you save the inconvenience of removing the pedal cover doing this, this action will eventually strip the threads on the valve and it will need replacement in a few years. We suggest removing the water valve entirely as recommended above.

  • Do not flush antifreeze down the toilet as recommended in the Sealand manual; this will harm your composting toilet system.

Limited Use - Central Composting System

For limited use (i.e. up to a couple of weekends a month) in cold temperatures, the unit can be used simply as a holding tank. For this, sufficient space must be available in the Bio-drum and the drum should not be rotated if it contains frozen compost. Electric units should be plugged in when in use, so that the fan eliminates all odors even though no composting is taking place. If you have a Non-Electric model or an AC/DC that you are using primarily in DC mode, you should install a 12 Volt fan to assist airflow during use in the winter months.

This advice is applicable to all planning on using the unit once a month or so in winter. If you are planning on using the unit more frequently during the winter months, please follow the advice in the section below.

Extended Winter Use

For continuous or extended use (i.e. every weekend or residential use) in winter, the composting unit will have to be kept warm (at least 55° - 60° F) so the composting activity does not stop.

  • Insulate all piping in unheated areas to avoid ice blockage including vent stacks (on all electric units), and waste inlet and drain piping where appropriate.

  • While the composting unit is not in use, energy costs can be reduced by installing a speed control on the fan so that very little cold air is being pulled in and the heater is operating less frequently. This speed control is available from our parts department.

  • If you are planning on installing a unit in a climate with extreme temperatures (ie Alaska or Northern Canada), consider installing a 3" pipe around the insulated 2" pipe to add an extra measure of insulation. Many of our customers in these areas also use heat tape or self-regulated heat cable along the length of the vent to keep ice from blocking the vent in the winter months. Contact us for additional advice if planning to install a unit under these circumstances.