the switch located outside in the lower left of the W/H turns the element on and off. KZ also has the dual switch inside the trailer allowing all control from inside. The outside switch also has a hole drilled through it and there should be a small clevis pin that goes through the hole to prevent the element from being turned on without water. Most dealers will clip the clip on a wire when it is removers to prevent loss. Also when filling the heater NEVER bleed the air using the pressure relief valve as it will remove too much air and cause the relief valve to drip.
