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Part number IWHA016A/1103
11
PLUS Line Instruction Manual Supplement
PLUS &
PLUS WATER HEATERS WITH GAS-FIRED WATER BOILERS
Start-up4
Follow Boiler Manual procedures
1. Follow all procedures in the boiler manual to start
up and verify operation of the boiler.
Set space heating operation
Verify space heating mode
1. Press the “Mode” button until the display shows
“Para.” This is the parameter mode.
2. Press the “Step” button until the display first digit
shows “3.”
3. The last digit must show “1.” If any other number
displays, press the “+” button until “1” shows in
the right-hand digit. Press the “Store” button to save
this setting.
Set space heating target temperature
1. Press the Ultra control panel “Step” button until the
display first digit shows “4.” The right 3 digits show
the outlet water temperature setting.
2. Press the “+” or “-” button to change the setting to
the desired outlet water temperature. (The factory
default setting is 190 °F.)
a. Outdoor sensor installed — Setting is the target
temperature for outdoor temperature at or below
32 °F. At higher outside temperatures, the Ultra PhD
control module calculates the target temperature. (See
Ultra Control Supplement for detailed discussion of
outdoor reset.)
When a summer/winter switch is used, closing the switch
will disable the boiler (space heating) circulator during
summer operation.
b. Outdoor sensor not installed — Setting is the target
temperature at all times.
3. Press the “Store” button to save the setting.
PLUS water heater operation
1. The PLUS water heater thermostat must be
connected to low voltage terminal strip terminals 3
and 4 as shown on page 10.
2. When the water heater thermostat calls for heat, the
module shuts down the boiler circulator, activates
the water heater circulator and immediately sets
target outlet water temperature to 190°F. This
provides automatic priority heat allocation to the
indirect water heater for maximum response and
recovery.
3. The water heater circulator continues for 30
seconds after the heating cycle to deliver the most
possible heat.
Check PLUS operation setup
1. Go to step 2 if the control is in Parameter mode
already. Press the “Mode” button until the display
shows “Para” (parameter mode).
2. Press the “Step” button until the display first digit
shows “2.”
3. The last digit must show “1.” If any other number
displays, press the “+” button until “1” shows in
the right-hand digit. Press the “Store” button to save
this setting.
4. The Ultra PhD control module turns on the PLUS
circulator when the indirect water heater operating
control closes. The control module shuts off the
boiler circulator (stops space heating) during calls
for DHW heating.
Verify operation — space heating
NOTE: “[ _ _ _ _ ]” in the following indicates the
characters that should show on the Ultra display panel.
“180” in the right 3 places means the display shows the
measured boiler water temperature. The number shown
will not necessarily be 180.
1. Turn down aquastat on PLUS tank. If necessary, turn
off power and remove one of the PLUS aquastat
wires to ensure boiler will not receive a DHW heat
call.
2. Turn off power to boiler at service switch.
3. Wait a few seconds, then turn on power to boiler.
[A180] (self-check on power-up, for a few seconds)
[0180] (no call for heat)
4. Raise room thermostat to call for heat.
[5180] (blower/circulator on) The blower and boiler
circulator energize and the control checks for air flow.
[1180] (prepurge) After a few seconds delay (control self-
check), blower speed will increase to ignition speed.
The blower will run in prepurge for 10 seconds.
[2180] (ignition) After prepurge, the control module
opens the gas valve and starts ignition spark.
a. If burner flame proves within 4.5 seconds, burner
continues to fire. Burner will fire at start-up rate
— 50% of maximum input — for about 10
seconds to allow flame to stabilize.
b. If burner flame does not prove within 4.5 seconds,
control module attempts ignition sequence again.
Flame must prove within 5 attempts or control
will lockout (display will show [E 02]).
c. Verify flame failure operation by closing boiler
manual gas cock to prevent gas flow. Open manual
gas valve after testing.