The Tecmark Vacuum Switch V4003P-DX (also referenced as a Tecmark 21A SPDT Vacuum Switch) is a reliable replacement safety component designed to detect vacuum (negative pressure) conditions in spa plumbing. It ensures proper system protection by signaling the control board when there’s excessive suction or improper suction levels, helping prevent unsafe conditions around pump suction and heaters.

• Tecmark 21A SPDT Vacuum Switch
• Negative Pressure Detection — Monitors vacuum (negative pressure) on the suction side of the pump or in a pressure/vacuum circuit and converts it to an electrical output.
• Safety Interlock Function — Acts as a safety interlock device that opens or closes its circuit to inhibit pump or heater operation if vacuum is outside the set range, protecting equipment and users.
• SPDT Switch Configuration — Has a Single Pole Double Throw electrical configuration suitable for a variety of control logic setups (ON/OFF detection).
• Durable Construction — Built with sturdy components and 1/8″ MPT threaded connection for secure fit and long-term reliability.
• Electrical Rating — Rated up to 21 A (commonly referenced 25 A in some specs) at 125–250 V AC, making it capable of switching larger loads safely. 
• Compatibility — Compatible with systems that require a vacuum sensing switch (often found on the suction side of pumps or spa suction safety loops). Frequently used as a replacement for Cal Spa vacuum switches and similar OEM parts like V4001P‑DX.
  Always verify your spa model and control requirements before ordering.
• Part no. V4003P‑DX

Why choose this product?

This vacuum switch helps maintain safe and consistent operation of your spa system by ensuring critical safety thresholds are respected. Replacing a worn or faulty vacuum switch eliminates unsafe suction conditions, helps prevent pump or heater damage, and restores proper control logic in your spa or hot tub system.