Oxygen depletion within a tightly sealed compartment could cause dizziness and
headaches and may lead to flame loss within heater.
When the heater is operated in a tightly constructed enclosure, which restricts air flow, it is
recommended that combustion air be connected from an external source to the rain-shield inlet (3).
Combustion air piping is necessary to prevent depletion of oxygen in a tight enclosure.
An L-shaped cover is attached to the rain shield assembly with six screws.
Depending on its installed position, it can be used to block off either the bottom of
the rain shield or the hole for the attachment of combustion air piping. Rotate the
cover as needed for this particular installation.
Mount and connect the room thermostat (4) to the heater as follows:
Select a thermostat mounting site. Use the following rules when selecting a site:
Select a well-insulated inside wall.
Select a site that will allow for easy access and good visibility.
Select a site that is out of direct sunlight.
Select a site that is free from drafts and that will not be in line with combustion
air inlet (3) or heated air discharge flow (5).
Remove thermostat cover and mount them thermostat (4) vertically as shown in Figure 4-1.
Measure the distance from heater control panel.
If required cable length is 20 feet or less, select three wire cable (MIL-C-
27072, or equivalent) having 14-gage conductors.
If required cable length is more than 20 feet, select three wire cable (MIL-C-
27072, or equivalent) having 12-gage conductors.
See Figure 4-2. Wire connector and thermostat as shown.
Thread connector onto control panel THERMO connector.
Prepare a DC power cord using three-wire cable and a DC connector. The B terminal must be negative
(-) and the A terminal must be positive (-). Connect the ground to C terminal. See Figure 4-2.
Connect the power cord to the power source and to the control panel POWER receptacle.
Preliminary Servicing and Adjustment of Heater.
Make sure the fuel supply is adequate for checks and adjustments.
Set the room thermostat knob to less than the enclosure ambient temperature.
Set the ON-OFF switch on control panel to ON. The heater must not. start. Place ON-OFF switch to
Set the thermostat to a temperature above enclosure room temperature.
Set the ON-OFF switch to ON. After an approximate 30 second delay the heater will start. Check that
the blower operates and the heater circulates warm air.