Jabsco 18916-Series Diaphragm Pump Pressure Switch Kit

Overview

The Jabsco 18916-Series is a diaphragm pump pressure switch kit range for matching Jabsco PAR-Max, legacy PAR-Max, and HotShot pump applications by pressure rating and pump subgroup.

These switch kits are used when a compatible freshwater or washdown pump needs pressure switch service rather than full pump replacement. The range covers 25 PSI, 35 PSI, 40 PSI, 50 PSI, and 60 PSI configurations, so the correct version should be matched to the pump model or series already installed on board.

On a boat, the pressure switch is the part that lets the pump respond to system pressure. When the plumbing system drops below the switch setting, the pump can start automatically, so power should be disconnected and system pressure relieved before service work begins.

Key features

• Replacement pressure switch kit range for compatible Jabsco diaphragm pump systems.
• Pressure ratings across the range include 25 PSI, 35 PSI, 40 PSI, 50 PSI, and 60 PSI.
• Variant coverage includes legacy PAR-Max pumps, PAR-Max 2, PAR-Max 3, HotShot 3, and HotShot 4 pump groups.
• Useful for freshwater pressure systems and washdown pump applications where the pump body remains serviceable but the pressure switch needs replacement.
• Model-specific selection helps keep the pump matched to the pressure setting used by the original installation.
• Compact service-part format supports repair in tight marine spaces such as lockers, utility compartments, under-sink areas, and pump bays.

Variants

The 18916-Series is offered in several pressure and pump-compatibility configurations. The main differences across the range are the PSI rating and the applicable Jabsco pump subgroup.

The listed versions cover legacy PAR-Max model endings, specific PAR-Max 2 and PAR-Max 3 model references, and HotShot 3 or HotShot 4 pump series references. Match the replacement switch to the existing pump model and pressure rating before installation.

Installation and setup

Before removing the old switch, disconnect power to the pump and open a faucet or valve to relieve system pressure. This matters because pressure-controlled pumps can start without warning when connected to power and the switch senses pressure below its shut-off point.

The pressure switch is typically serviced at the pump head area. Access can be limited on boats, so confirm that there is enough working room around the pump for removing the switch screws and reconnecting the wiring without straining the leads.

Compatibility and fit

This range is not a universal pressure switch selection. The correct kit depends on both pressure and pump family, including the applicable legacy PAR-Max suffix, PAR-Max model reference, or HotShot series reference.

It is a practical match for boat owners, yards, and service technicians maintaining Jabsco freshwater or washdown pumps where the original pump is staying in place and the pressure switch rating needs to remain consistent with the system.

Use on board

A working pressure switch helps the pump cycle normally as faucets, showers, or washdown outlets are opened and closed. Replacing a worn or incorrect switch can help address pressure-control issues when the rest of the pump and plumbing system have already been checked.

For saltwater and high-vibration marine spaces, installation quality matters. Keep wiring secure, avoid water collecting around electrical connections, and confirm that the pump location remains dry enough for the pump type and service parts being used.