Johnson Pump automatic float switch AS888 — 15A mercury-free bilge and sump pump control

The Johnson Pump 26014 AS888 is a mechanical automatic float switch that uses a rolling steel ball and micro-switch to control bilge or sump pumps up to 15 amps without mercury.

The AS888 by Johnson Pump is a compact, universal-fit float switch engineered for reliable on/off control of pumps in marine, RV, and light industrial applications. Its mechanical design replaces hazardous mercury with a rolling steel ball and a sensitive micro-switch, offering a durable, low-maintenance alternative for triggering pumps and alarms. The unit supports loads up to 15 amps and mounts easily in cramped compartments or standard float switch sockets.

How does this float switch trigger a pump without mercury?

The AS888 relies on a sealed chamber with a precision steel ball that rolls to make contact with an internal micro-switch as the water level rises. This mechanical action closes the circuit to start a pump and opens it when the level falls, providing straightforward electrical switching without liquid mercury. The absence of mercury reduces environmental and handling concerns while keeping switching performance consistent.

• Sealed mechanical chamber with rolling steel ball for reliable contact
• Micro-switch actuated by ball movement for stable on/off transitions
• No mercury — safer for marine and recreational environments
• Rated for up to 15 AMP motor loads

Where and how can I mount the Johnson Pump AS888?

The AS888 fits universal float switch sockets or can be mounted in typical bilge compartments, sumps, or pump wells. Its compact footprint allows installation in confined spaces; ensure the switch is positioned vertically so the ball moves freely and water reaches the sensing chamber. Use appropriate cable routing and strain relief to prevent abrasion or chafing in vibrating environments.

• Universal-fit design for common bilge and sump sockets
• Vertical mounting recommended for reliable ball movement
• Compact size suits tight compartments and boat bilges
• Use marine-grade connectors and strain relief for durability

What electrical and performance specs should I consider?

The switch is engineered for mechanical simplicity and electrical reliability: it carries a maximum continuous load of 15 amps and uses a micro-switch to handle the electrical circuit. Check pump starting current and any inrush requirements — for motors with higher startup draws, use a compatible relay or contactor to protect the switch. Proper circuit protection and wiring gauge will extend switch life and ensure safe operation.

• Maximum continuous rating: 15 AMP
• Micro-switch provides the electrical contact; consider relays for high inrush loads
• Mechanical operation minimizes electronic failure points
• Use correct wire gauge and fuse/circuit breaker per pump specifications

How long does the Johnson Pump AS888 last and how do I maintain it?

Longevity depends on installation environment and electrical load; the mechanical design resists common failure modes like water intrusion that affect some electronic sensors. Periodic inspection for debris, corrosion, and free movement of the internal ball will keep it operating smoothly. Replace the switch if the ball becomes stuck, contacts are corroded, or electrical performance degrades.

• Inspect periodically for fouling or corrosion
• Ensure free vertical movement of the internal steel ball
• Protect electrical connections from moisture and vibration
• Use a relay for heavy-starting pumps to extend switch life

Who is this for: The Johnson Pump 26014 AS888 Automatic Float Switch is aimed at boat owners, RVers, small-craft operators, and facilities managers seeking a simple, mercury-free mechanical float switch for bilge and sump pump control. It's especially suitable when compact size, universal fitment, and straightforward installation matter more than advanced electronic features. Choose the AS888 when you want a rugged, low-maintenance switch to reliably control pumps up to 15 amps in marine and light-duty applications.