18
Pump Control Mode
(Available on the T-D2-IN / 510 model only)
The T-D2-IN / 510 water heaters 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 a
recirculation pump, connect the pump to the “Pump
connector” in the water heater as shown in the diagram
below . (In an Easy-Link System, connect the pump ONLY
to the “PARENT” unit .) The pump is to be connected using
suitable relays shown in the diagram below .
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 .
CAUTION
In an Easy-Link System, the pump must
be connected to the “Pump connector”
in the “PARENT” unit only
. If the pump is
connected to any of the
“CHILD” units
, the
pump will not work .
Recirculation
pump
Connect to this
“Pump connector”
Power supply
for relay
Power supply
for pump
120 VAC
220 VAC etc
120 VAC
220 VAC etc
for relay
Thermal relay
for
additional safety
These components
are NOT included
with the water
heater and are
external to the
unit . They must be
acquired separately .
Easy-Link System
(Available on the T-D2-IN / 510 model only)
General
The T-D2-IN / 510 water heaters can be connected with
other heaters of the same model with communication cables
to work as a
m
ultiple-
u
nit manifold system .
•
The Easy-Link System allows up to 4 units to manifold
together .
•
A communication cable (gray color) comes with each
T-D2-IN / 510 model .
You can manifold from 2 to 4 units without the need for a
Multi-Unit Controller . A 4-unit system has full automatic
modulation between 11,000 BTU/h and 796,000 BTU/h .
Gas In
Cold In
Hot Out
CAUTION
•
The Easy-Link System is limited up to
4
units
. If you connect more than 4 units,
only the first 4 units will work as a part
of the Easy-Link System . The other
additional units will not work correctly and
fluctuating water temperatures or no hot
water may be a result .
•
All units within an Easy-Link System
must be of the same exact model.
Easy -Link System is backward com-
patible with the T-K3 and T-K3 Pro,
no other models cannot be combined
together to form an Easy-Link System
.
•
Only change DIP switch settings with
power off.
Easy-Link Connection Procedures
1 . Make sure the power to the water heaters are off .
2 . Verify the set temperatures of all units within the
system . Every single water heater must be set to the
same set temperature . See *Note on the next page .
3 . Select one unit to be the
“PARENT”
unit with power off .
4 .
“PARENT”
unit:
Locate the two banks of DIP switches at the right of the
7-Seg LED on the computer board of the unit that you
select to be the
“PARENT”
unit . Change DIP switch
No . 1 on the
right bank of DIP switches to the ON
position
. See the computer board diagram as shown
in the next page . Do not change any DIP switches on
any of the
“CHILD”
units .
5 . Between the
“PARENT”
and the
“CHILD-1”
units:
Connect the
“PARENT”
connector of the
“PARENT”
unit to the
“1”
connector of the
“CHILD-1”
unit .
6 . Between the
“CHILD-1”
and the
“CHILD-2”
units:
Connect the
“2”
connector of the
“CHILD-1”
unit to the
“1”
connector of the
“CHILD-2”
unit .
7 . Between the
“CHILD-2”
and the
“CHILD-3”
units:
Connect the
“2”
connector of the
“CHILD-2”
unit to the
“1”
connector of the
“CHILD-3”
unit .
