The Zonefirst MMZ3 is a purpose-built zoning control panel engineered for single-stage heating and cooling systems. As the direct replacement for CMM-3 legacy boards, the MMZ3 provides seamless modularity for managing 2 or 3 independent zones with 24Vac 2 or 3 wire damper actuators. This panel features advanced surface-mount technology for maximum reliability and utilizes color-coded, screwless terminal blocks to significantly reduce installation time for technicians. The board is fully compatible with standard 4-wire or 5-wire thermostats (R, C, W, Y, G) and includes high-visibility system status LEDs to simplify troubleshooting at the plenum. With integrated brownout protection and a resettable circuit breaker, the MMZ3 ensures the HVAC zone control board and transformer are protected against common electrical shorts in the field. Key Benefits for HVAC Contractors Direct CMM-3 Compatibility: Designed for rapid retrofit applications, serving as the official Zonefirst CMM-3 replacement without requiring extensive rewiring. Versatile Damper Control: Successfully operates both 2-wire and 3-wire 24V actuators, including RDS, RTS, and ZDS series motors. Simplified Wiring: Features push-in terminal blocks that eliminate the need for small screwdrivers, ensuring secure 24V zone panel connections. Intelligent Mode Logic: Employs a first-call-priority system with a 20-minute time share and automatic purge to prevent short-cycling. Fan Control Logic: Includes a Fan-On-In-Heat (FIH) jumper, essential for hydro-air or electric heat applications where the blower must engage immediately. Common Questions about the MMZ3 Does the MMZ3 support heat pump systems? No, the MMZ3 is specifically designed for single stage heating and cooling equipment. For heat pump or multi-stage applications, a universal panel like the H32 is required. Can I use this board to replace a failing CMM-3 unit? Yes, the Zonefirst MMZ3 is the modern drop-in replacement tailored to match the footprint and basic terminal logic of the older CMM-3 series. What power source is required for the MMZ3 and dampers? A dedicated 24VAC 40VA transformer is recommended to provide sufficient current for the HVAC damper control logic and all connected zone actuators. Disclaimer: While we strive for 100% accuracy, product data and specifications are subject to change. Please contact our team to confirm compatibility or technical details before purchasing.
