Hot Spring Heater #73994

4 kw 240 volts 2.25" x 15" stainless steel tube factory replacement.

The heater is a flow through type heater. The heater is powered and controlled by the control box. That is, power is supplied to the heater when the control thermostat determines the spa temperature is too low.

The heater is inserted in the discharge of the jet pump plumbing and is located under the control box. The heater is attached to the spa's plumbing using compression fittings at either end.

Specifications:

• 220 Volt AC, 4.0 kW, 18 Amps

1. Disconnect power to the spa.
2. Drain the spa.
3. Remove the equipment compartment door.
4. Open the control box lid.
5. Disconnect the pressure switch connection wires from the pressure switch.
6. With two small wrenches of the same size, loosen the nuts that secure the heater connecting bars. Then disconnect the ground wire attached to the heater.
   
   WARNING: Always use both wrenches to loosen the heater connecting bar. The bottom nut is fused to the heater terminal to prevent the terminal from being twisted when the top nut is turned. If only one wrench is used to loosen the connecting bar, the torque applied to the heating element will be too great, and the heater will be permanently damaged.
7. Remove the High Limit Sensor for the heater.
8. Unscrew the heater inlet and outlet compression fittings.
9. Rotate heater and pressure switch clear of the control box. Remove the pressure switch from the heater.

   CAUTION: There may still be some residual water in the plumbing.

   Installation:

   Reverse the removal procedure to install the heater in the equipment compartment (refer to the pressure switch installation procedure if necessary).

   NOTE: Be sure that the pressure switch and high limit sensor are positioned correctly before you slip the heater in place. After you are finished with the installation, switch the jet pump to high speed and check the compression fittings for leaks.

73994 Heater 4kw is for the following models: