ZA024Q4A2 - Zone Sentry Valve Replacement Head - NC 24VTaco ZA024Q4A2 Replacement Zone Sentry Head NC 24V The Taco ZA024Q4A2 is a replacement actuator head for Taco Zone Sentry zone valves. Designed for fast, tool free installation, it snaps easily onto the valve body without the need to drain the system. The low power electronic actuator is energy efficient and reliable, making it a smart upgrade or repair component for hydronic zoning systems. This replacement head is compatible with Taco Zone Sentry