Bilge Pump Switches

Equip your bilge pump with a switch for the automatic operation of your pump. A switch will automatically activate the bilge pump when the water level rises in the bilge and deactivate the pump as the water level is lowered. Switches available are the top-of-the-line digital Ultima Switch, an Electro-Magnetic Float Switch and a traditional Float Switch; all Mercury-free.



Ultima Switch – Electronic Automatic Switch

The solid-state electronic automatic switch Ultima Switch uses the patented Mirus field effect detector cells producing micro-electrical fields that detect disruptions caused by water and fluids. Detector cells are totally sealed and are never in contact with the water, will not corrode and are not affected by oil or foreign debris.

  • Limited 3 Year Warranty
  • No moving parts, totally sealed solid state electronics and field detectors
  • Environmentally sensitive; no mercury
  • No exposed sensors eliminate corrosion possibilities
  • Activates at a 50 mm (2″) fluid level and deactivates at a 20 mm (¾”) fluid level
  • A three second delay prevents false starts from water sloshing in the bilge
  • Ultima Switch is rated to handle pumps up to 20A at 12V or 10A at 24V.


Technical Data

Part No. Part No. USA Description Max Amp.
34-36303 36303* Ultima Switch Electronic Automatic Switch 12/24V 12V: 20A24V: 10A
* base, as seen in the photo, included for USA version only, the Ultima Switch fits onto the base of standard Johnson Pump Submersible Bilge Pumps

Electro-Magnetic Float Switch

Compact mechanical switch offers a combination of reliable solid state electronics and a sealed float switch.

  • Limited 3 Year Warranty
  • For 12V or 24V
  • False start prevention
  • No mercury
  • High impact plastic and encapsulated electronics adds up to dependability
  • Activates pump at 2″ water level, deactivates pump at ¾” water level
  • The switch is designed to attach to the SPX FLOW Johnson Pump Cartridge bilge pumps. When attaching to other SPX FLOW Johnson Pump bilge pumps, use the adapter provided.


Technical Data

Part No. Part No. USA Description Voltage Max Amp.
34-1900B-12V 36152 Electro-Magnetic Float Switch, 12V 12 V 15 A
34-1900B-24V 36252 Electro-Magnetic Float Switch, 24V 24 V 8 A
AS888 – Automatic Float Switch

For fully automatic bilge pumping operation, connect the AS888 Automatic Switch to your bilge pump. The AS888 Automatic Switch has a time-proven micro switch without mercury.

  • Limited 3 Year Warranty
  • When water exceeds the acceptable level, the pump is turned on by a rolling steel ball, which changes the pressure on the micro switch.
  • The AS888 attaches to any SPX FLOW Johnson Pump bilge pump through the clip on ”T-slot”
  • Can be used with 12, 24 or 32V systems


Part number

Part No. Part No. USA Description Max Amp.
34-888 26014 AS888 Automatic Float Switch 15 A