Lennox M33C024S4

70
12. Master Valves (3 to 5 Zone Outdoor Units)
• 3-zone, 4-zone and 5-zone (not 2-zone)
multi-zone units have a master valve on each
refrigerant line.
• The master valve controls refrigerant to all of
the zone-supply valves.
• Open the master valves prior to opening the
zone-supply valves.
Liquid Line
Master Valve
Vapor Line
Master Valve