RESISTIVE WATER SENSOR FOR HOT TUB SPA HEATING ELEMENT

摘要

A dry fire protection system for a spa and the spa's associated equipment. A heating element heats the spa's water. A resistive water level sensor senses that the level of water around the heating element is higher than a predetermined height or lower than a predetermined height, and a heating element deactivation device electrically deactivates the heating element when the water level around the heating element falls below a predetermined level. In a preferred embodiment, the heating element deactivation device is an electric circuit comprising a comparator circuit and a control circuit.