Allied Pressure Switch [800140-3] (3903-EADE) 34-0178-K for Pool & Spa

Allied 800140-3 (3903-EADE) is a universal pressure switch designed for pool and spa heater systems. Introduced in 1993 for the industry, it delivers a stable trigger with a 2.5 lb differential to prevent relay chatter and keep your equipment running smoothly.

• Electrical rating: 1–25 A at 24–240 VAC
• Pressure differential: 2-1/2 lb to minimize relay chatter and ensure clean switching
• Setpoint: 2 psi pressure switching range
• Connections: 1/8" NPT (MPT) plumbing connection; available as 1/8" barb fittings; tubing adapters (3/16" or 1/4") sold separately
• Pan material: Plastic pan for lightweight, corrosion-resistant mounting
• Switch type: Single Pole, Single Throw (SPST)
• Compatibility: Designed for pool and spa heaters, including gas millivolt systems
• Replacement context: Obsolete universal pressure switch; replacement shown in the second photo to align with the 800140-3 family
• Brand: Allied Innovations, a trusted name in spa and pool components

With its 2-1/2 lb differential, this switch minimizes relay wear and oscillation, delivering consistent on/off control for your heater. The 1/8" NPT (or barb) plumbing options simplify installation in legacy systems, while the broad electrical range supports a wide variety of control circuits. Ideal for service technicians and DIY enthusiasts restoring older pool and spa setups, the Allied 800140-3 helps you recover reliable performance without guessing at compatibility.

Allied 800140-3 (3903-EADE) - OBSOLETE

Universal Pressure Switch - Replacement shown 2nd Photo

Introduced in 1993 specifically for the pool and spa industry, this pressure switch is designed with a 2-1/2 lb differential to completely eliminate oscillating or chattering relays.