L.B. White HW120 Plus Therma Grow - Manual (Page 14)

For initial start-up after heater installation, follow steps 1-6.
For normal start-up, simply set the thermostat above room
temperature.
1. Connect electrical cord to an approved electrical outlet.
2. Set thermostat to desired room temperature.
3. This heater has a manually operated toggle style
selector switch located on the top of the control box.
(Open the fan motor access panel to view) This switch
allows you to either heat or ventilate (no heat). See
Fig. 9 for selector switch positions.
FIG. 9
A. Heating
a. Open all manual fuel supply valves. Check for gas
leaks using an approved leak detector. The gas control
valve on the heater has a manual shut-off feature
incorporated into the valve assembly. Make sure the
indicator on the valve is turned to the on position. See
Fig 10
FIG. 10
b. This heater includes a hot surface ignition (HSI) control
module for purposes of controlling the timing of the
ignition process of the heater as well as monitoring of
the safety functions. The HSI module is contained
within the control enclosure.
When the selector switch is positioned to heat, the red
light emitting diode (LED) on the ignition control will be
on. This LED indicates the status of the heater. The
LED is visible through the plastic window of the control
box. A constant light from the LED is an indicator that
the heater is functioning correctly.
Any flash pattern by the LED indicates there is a
problem in the operation of the heater. Refer to the
troubleshooting decal adjacent to the control box for
assistance in troubleshooting. Only qualified and
properly trained personnel shall service or repair the
heater.
B. Ventilation
When the selector switch is positioned to vent, the red
light will NOT be on. The fan motor will start, but the
igniter will not spark, nor will ignition occur. This
feature is used typically when heat is not needed, but
a i r c i rc u l a t i o n i s r e qu i r e d . To d i s c o n t i n u e t h e
ventilation feature, position the switch to off or heat, or
use the interconnected contacts (customer supplied) to
accomplish this task.
C. Off
Position the switch to midpoint.
On a call for heat, the motor will start and run for five
(5) seconds and then stop. This pre-purge is a safety
feature and a normal operational characteristic prior to
ignition taking place. After the motor has stopped, the
igniter will heat up (approximately 17 seconds). After
igniter warm up time has been achieved, the motor will
start again and shortly thereafter ignition will occur.
NOTE: It is normal for air to be trapped in the gas
hose on new installations. The heater may
attempt more than one trial for ignition before
the air is finally purged from the line and
ignition takes place.
4. The HSI control will make up to three trials for ignition.
Each trial for ignition will take approximately 20
seconds. The first two trials for ignition will occur
within 40 seconds if ignition is not achieved. A 15
minute wait period will then begin after the second trial
for ignition has taken place. After the 15 minute time
has passed, the third and final trial for ignition will take
place. If ignition is not achieved at this final trial, the
system will lock out, and a three flash pattern will be
indicated by the LED.
5. The gas control valve in this heater is a two stage
control. When a call for heat occurs, the valve will
o p e n to i t s f i r s t s t a g e r a te . D e p e n d i n g u p o n
temperature requirements and temperature control
setting, the valve will then either remain at first stage
heat rate before the temperature control is satisfied, or
the valve will open completely to its second stage
capacity. If the valve opens to its second stage
capacity, it is designed to revert back to its first stage
heat rate before controller shuts the heater down.
6. Do not exceed input rating stamped on nameplate or
manufacturer’s recommended burner orifice pressure
for size orifice(s) used. Make certain that the primary
air supply to main burner is open and free of dust, dirt
and debris for complete, proper combustion.
ON
OFF
HEAT
(UP)
OFF
(MID)
VENT
(DOWN)
Start-Up Instructions
14