Paloma PH2-20R DVSN, Engineering Handbook

Page: 133 / 172

Tankless Water Heater DUOnex™ 2-Unit System
Installation Instructions
It is very important that all persons who are expected to install, operate or
adjust this DUOnex™ system and/or water heater read these instructions
along with those instructions provided with the tankless water heater.
Recognize this symbol as an indication of Important Safety Information!
!
Refer to the Use and Care Manual provided with your tankless water heater for the proper installation procedures.
This kit contains:
1 - DUOnex™ Cable, 2 - Cable Clamps, and 2 - Screws
Install two tankless water heaters of the same model together
in a parallel plumbing application (see Figure 2) and in
accordance with the instructions in the Use and Care Manual.
NOTICE: A Remote Control Thermostat is included with
each water heater. When using the DUOnex™ system, only
one (1) Remote Control Thermostat is needed. Connect only
one (1) remote control to either water heater following the
instructions provided in the Use and Care Manual. This water
heater will become the main unit. The installed Remote Control
Thermostat will control temperature and functionality of both
water heaters. Keep the unused remote control as a spare.
1. Make sure power is disconnected and turn off gas and water
to both water heaters, then remove the front cover from each
water heater.
2. Feed one end of the DUOnex™ cable through a grommeted
hole in the bottom of the fi rst heater.
3. Plug the cable into the connector marked “F” in the upper right-
hand corner of the Control Board (see Figure 1). The connector
will only fi t one way. Press until the connector snaps into place.
4. Secure the DUOnex™ cable with the clamp and screw provided
to the bottom right of the Control Board (see Figure 1).
5. Change the #4 Dip Switch setting to the “ON” position (see
Figure 1 inset) on that water heater.
6. Pass the other end of the DUOnex™ cable through a
grommeted hole in the bottom of the second water heater.
7. Plug the cable into the connector marked “F” in the upper right-
hand corner of the Control Board (see Figure 1). The connector
will only fi t one way. Press until the connector snaps into place.
8. Secure the DUOnex™ cable with the clamp and screw provided
to the bottom of the Control Board (see Figure 1).
9. Change the # 4 Dip Switch setting to the “ON” position (see
Figure 1 inset) on that water heater.
10. Attach the front cover on each unit, and turn on the power,
gas, and water.
11. Test the units by turning on a tub or shower fi xture.
Notice: The DUOnex™ System is designed to electronically con-
trol two tankless water heaters operating as one. Depending upon
the hot water demand, one or both units may be in operation. To
test both units, increase the hot water fl ow by turning on more than
one hot water appliance or fi xture.
- 133 -
Control Board
- Figure 1
ON
1 2 3 4
DIP1
ON
OFF
1 2 3 4
SW1 SW2
SW3
ON
1 2 3
4
DIP1D
IP
1
ONO
N
OFFO
F
F
1
2 3 4
Dip
Switch
Connector
“F”
DUOnex™
Cable
Cable clamp
and screw
LED
Dip Switch
Position #4
Figure 1
inset
Type 1
DUOnex
TM
Installation