Circulation with Filter

This easy upgrade allows you to circulate and filter the water which  keeps the water clean and removing the need for draining after each use.   The circulation also means that the water is evenly mixed so that you don't have to stir it with a paddle to mix the layered hot and cold water. This option allow a further upgrade to an electric heater giving you a hybrid heating system with both wood and electric.  If you are looking at using the tub year round then the heater will prevent freezing during the winter without having to fill and drain the tub every use.  You can independently drain only the wood fired hot tub heater and still run the electric heater in the winter.

This system is recommended when using the Inferno (Xlarge) heater, as this powerful heater can often boil the water inside the heater with just thermosiphon resulting in potentially scalding water temperatures.  The pump accelerates the water flow reducing the temperature differential and mixes the water in the tub eliminating the layering of the hot water on the top and cold on the bottom.  The filter keeps the water clean and reduces the need to drain every use. This system is also used when a close distance from the tub to the heater is not achievable such as when a tub is sunk into the deck.