Indoor Ventilation Kit
Indoor Installation Kit • Therma Grow
www.lbwhite.com
Indoor Installation Kit • Therma Grow
6
2. Make two electrical leads of proper length and
gauge. Attach terminals from the kit to these leads.
See Fig. 9.
FIG. 9
LEAD A
LEAD B
BUTT SPLICE
1/4 IN FEMALE
TERMINAL, 90º FLAG
PROPER LENGTH AND
GAUGE WIRE
3/16 IN
FEMALE TERMINAL
3. Connect the leads as follows. Refer to appropriate
wiring diagram on page 6.
Lead A
-- Connect the end with the 3/16 in. terminal to either
terminal of air proving switch at the air inlet.
-- Route the other end with the butt splice up through
the bottom of the control box
-- Connect the butt splice to the blue lead in the control
box which had its terminal removed.
Lead B
-- Connect the end with 3/16 in. terminal to remaining
terminal on air proving switch at air inlet.
-- Route the other end of this lead up through the bot-
tom of the control box.
-- Connect the 1/4 in. flag terminal from the kit to this
wire and connect this to terminal PSI on the ignition
control.
F. Completion
1. Secure all the wiring at the junction box and control
box with electrical fittings capable of preventing wire
abrasions and providing protection against dirt and
moisture entry.
2. Verify the completed wiring matches the appropriate
wiring diagram on page 6.
3. Connect the heater to its electrical and gas supplies
and test the installation by starting the heater.
NOTE: Connection with a thermostat or building
controller is required for further operation. Refer to
heater’s Owner’s Manual for control wiring instruc-
tions. Ensure 115 VAC is supplied to the exhaust
fan motor and air inlet shutter motor. Both will
operate when the heater starts.
a. On start-up, the heater’s fan motor will run for 5
seconds. During this time the air inlet shutter motor
will open the inlet, and the exhaust fan will start.
b. After 5 seconds, the heater’s fan motor will stop.
When the heater’s fan motor stops, the shutter
motor will close the air inlet and the exhaust fan
motor will stop.
Note: This is normal operation. The
ignition control is checking the
air proving switch at the air inlet
and in the heater for proper
operation before allowing an
ignition trial to continue.
• Shortly after the heater ignites, shut the heater
down.
-- The exhaust fan motor will stop.
-- The motor on the air inlet will gradually close the
shutters.
-- Ensure the inlet and exhaust fan shutters close
completely and do not bind.
4. Install the air proving switch cover over the
switch assembly at the air inlet. See parts
schematic FIG. 10.
5. Wrap the butt splice and wire nuts with electrical
tape.
6. Close and latch the control box and set the
greenhouse thermostat to desired temperature.
7. Ensure the motorized air inlet, the heater’s
air inlet, and exhaust fan are kept free of any
blockages.
8. Keep these instructions for future reference.
G. Parts Ordering Information
See Fig.10 for inlet shutter components.
The exhaust fan is available only as a complete
assembly. Exhaust fan part numbers:
-- Therma Grow™ 120 and 120 Plus: 24742
-- Therma Grow™ 220 and 220 Plus: 24741
All parts referred to in this instruction are available
by contacting L.B. White Co., LLC at (800) 345-
7200 from 7:00 a.m. to 5:00 p.m. Central Standard
Time.
