Burnham RSA Installation & Service Instructions Manual page 24

NOTICE
The Honeywell R8889 Control is available in two three (3) zone models and two four (4) zone models. Burnham
recommends using Model R8889A for three (3) zone systems and Model R8889B for four (4) zone systems.
Models R888C and R888D have less load capacity and may not operate with certain types of zone valves.
Up to four (4) R8889's may be used together to provide up to sixteen (16) individual zones. Only one (1) zone,
the first zone of the main control will provide priority zoning for the Alliance indirect water heater. If more
than four (4) zones are required, connect additional R8889's by wiring the A, B and C terminals of each control
together. Each R8889 requires a 120 volt power supply. If more than one (1) R8889 is used, set the panel
type switch to "main" on the first R8889 and set the panel type switch to "expansion" on the second, third or
fourth R888.
Figure 17: Different Manufacturer's Zone Valve Connections to Honeywell R8889
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