Takagi T-M50 - Manual (Page 22)

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PUMP CONTROL CONNECTIONS
The water heater can be used to control a recirculation pump. Proper pump control helps to
preserve the life of the system and saves energy as well.
The water heater pump control port is a “normally-open dry contact”, and therefore needs
additional components to properly control a recirculation pump. To control the recirculation
pump, connect the pump to the “pump terminal” in the water heater as shown in the diagram
below. (In a multi-unit system, connect the pump ONLY to the “PARENT” unit.) The pump is to
be connected using suitable relays shown in the diagram below (the pump terminal is
essentially only a dry contact. An external power supply and relays are required to
operate the pump).
Please make sure the relays are properly rated for the recirculation pump.
Using the water heater’s internal thermistors as a temperature control, the recirculation pump
will only turn on when recirculation is needed.
Connect to this terminal.
This is the pump terminal.
Power supply for relay
Power supply for pump
120 VAC
220 VAC etc
120 VAC
220 VAC etc
for relay
Thermal relay
Recirculation
pump
These components are NOT included
with water heater and are external to the
unit. They must be acquired separately.
CAUTION: In a multi-unit system, the pump must be connected to the
“Pump” terminal in the “PARENT” unit only. If the pump is connected to
any of the “CHILD” units, the pump will not work.