The 1804W is Thomas Products' entry-level flow-switch pump controller — four weatherproof outlets with two circuits: a positive-displacement flow switch (stainless steel return spring) toggles the two brown outlets when water flows, while two ivory outlets deliver continuous power for timers, alarms, and auxiliary equipment.

How does flow-switch control differ from pressure-switch control?

Flow-switch actuation responds to actual water movement rather than static line pressure. This prevents chemical overdosing during no-flow conditions — a common failure mode of pressure-switch controllers when downstream valves are closed but the pump remains pressurized. The 1804W's positive-displacement shuttle design tolerates dirty water and debris better than paddle-type flow switches.

What determines the number of outlets needed?

The 1804W provides two switched outlets (brown) for chemical metering pumps and two continuous outlets (ivory) for equipment requiring uninterrupted power — timers, data loggers, or solenoid valves. This eliminates the need for a separate power strip at the injection point.

How is flow calibration set?

The flow switch trips at 0.5 GPM increments up to a maximum of 6.0 GPM. The setpoint is mechanically adjusted at the shuttle assembly. Installation accepts any orientation — the SST spring returns the shuttle regardless of mounting angle — with a 1-inch Slip port on the rear panel.