Jabsco 37121-0010 Pressure Switch for Pressure Pumps (40 PSI) JAB-37121-0010

The Jabsco pressure switch 37121-0010 is rated 40 PSI and is suitable for use with Jabsco 36800 water pressure pumps.

Servicing instructions for the Universal Switch Replacement Kit:

Before beginning to service the pump, TURN OFF the power.

- Open an outlet to relieve the pressure in the system, if the pump is located below the supply tank, insure that the supply tank valve is closed to prevent water leakage during service.

Disconnect the wires from the terminals and remove the old pressure switch from pump. Determine pump model and vintage from diagram above. Assemble the parts for your model in sequence shown.

Tighten intermediate screws (if used) to 15 inch-pounds of torque. Tighten switch screws to 7 inch-pounds of torque. Replace the terminals with new terminals supplied in this kit.

*Note: The pre-mounted screw on the face of the switch housing is the pressure adjustment screw. This is a factory pre-set switch, DO NOT ADJUST. Possible damage to the system or even injury is possible. Adjustments other than the one made by the factory voids the warranty.

Externally on the plastic switch cover, there is screw hole to attach the cover to the switch once the switch is installed on the pump housing. A separate screw is provided for this installation, older types of Jabsco switches either did not use a cover or had a rubber boot.

Close all outlets. Turn power on to the pump. Open an outlet to bleed trapped air from system. When bubbles stop, close outlet and confirm that pump turns off automatically. Check for leaks and proper operation.

JABSCO DAMPENER NOTICE (Applies To models 36800-Series, 36950-Series, 36970-Series and 37215-Series only):
Note: When replacing the pressure switch on your Jabsco pump, it is important to check the pulsation dampener for possible collapse or deterioration. This can be easily done by first turning off power to the pump; then bleeding your water system by opening the outlets. Next, disconnect the pump from its installation and remove the base plate of the pump. The pulsation dampener is the large rubber chamber located directly under the base plate. If the dampener is soft or its shape is distorted or cut. it should be replaced. Insuring that the dampener is firm and resilient will minimize pump cycling and provide the best performance.