Tech Bulletin

1 TB-131

2/2017

Technical Bulletin 131 - Use of Circ-Logic™ for Building Recirculation

Purpose:

To recommend electrical connections to Rinnai Tankless Water Heaters equipped with Circ-Logic™, in order to

control external building recirculation pumps with electrical requirements greater than 120VAC.

The following guidelines are to be followed in addition to all applicable national, state and/or local wiring codes.

 Use listed Medium - Amp, Double Pole Single Throw - Normally Open (DPST-NO) Relay

Installation - The following installation MUST be completed by a qualified technician/electrician.

1. Disconnect power to the tankless water heater by unplugging the power cord or by turning off the electricity at

code required means of disconnect.

2. Install the 240V pump in accordance with installation instructions provided by the pump manufacturer.

3. Mount field supplied DPST-NO relay outside the water heater cabinet per the relay manufacturer instructions.

4. Locate the Circ-Logic™ harness (black and white wires with connector labeled “Cut wire to connect to pump”).

Cut off the connector and discard.

5. Splice the black and white wires from the tankless water heater, (extending as needed). Route the wiring

through the access hole to the relay location. The splicing should be located inside the water heater cabinet.

Terminate the wiring to the control side of the relay. All relay manufacturer recommendations as well as

any and all electrical codes must be adhered to.

6. Connect 240V from the building’s power supply to the relay. Then connect from the other side of the relay to

the pump.

Instructions:

CAUTION

This unit is supplied with 120 volts. Disconnect incoming power to the unit prior to performing any repairs or

installation to internal components or accessories.

CAUTION

Do not touch any other areas on the PC board besides the “SW” switches while power is supplied to the

appliance. Parts of the PC board are supplied with 120 volts.

WARNING

If the instructions contained in this technical bulletin are not followed exactly, a

fire, explosion, or electric shock may result causing property damage, personal

injury, or death.

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Technical Bulletin 131 - Use of Circ-Logic™ for Building Recirculation Purpose: To recommend electrical connections to Rinnai Tankless Water Heaters equipped with Circ-Logic™, in order to control external building recirculation pumps with electrical requirements greater than 120VAC. Instructions:  Use listed Medium - Amp, Double Pole Single Throw - Normally Open (DPST-NO) Relay The following guidelines are to be followed in addition to all applicable national, state and/or local wiring codes.
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7. Adjust the dip switch settings in the water heater. See Settings table below. In a multiple unit system, wiring should be connected to the unit with return line as shown to the left. Circulation Unit PVA Note: For Circ-Logic™ plumbing details, refer to, “Rinnai—Hot Water System Design Manual.” DPST-NO Relay Follow relay manufacturer guidelines for all electrical and grounding connections.