I have a Whirlpool Hydromassage Bathtub with a tub motor and heater underneath the tub. How can I determine whether or not the motor and heater are double insulated or not? Is it the material of their casing (metal or plastic)? I'm trying to determine whether or not I need to make an electrical bond between the motor, heater, and water lines. If the pump and heater are double insulated, then I would not need to bond and this would save me a lot of trouble. FYI... I have a Gemini Plus Pump Series pump model R125VS19C, Spec 0102E00C, Insulation Class B.