Millivolt wall thermostats are specially designed for use on self-
generating systems. They should never be used on line or low
voltage A.C. circuits.
Interior Wall - The thermostat can be installed on an inside wall.
Thermostat Bracket - The thermostat can also be attached to the
unit with the provided bracket.
1.
Determine which side of the unit the thermostat will be secured
to.
2.
Remove the front of the thermostat.
3.
Attach thermostat to the bracket using the two (2) screws
provided. See Figure 6. Replace the front of the thermostat.
NOTE: Bracket installation is optional. Do not use if not installing
an optional thermostat.
4.
If installing the thermostat bracket after the unit has been installed,
drill a hole in the side of the unit as shown in Figure 7. and
attach the bracket with a screw (not provided).
If installing the thermostat bracket before the unit is installed,
use the existing screw on the back of the unit to attach the
bracket to the unit as shown in Figure 7.
USE THIS EXISTING
SCREW (ON EITHER SIDE
OF THE HEATER) TO MOUNT
BRACKET IF INSTALLING BEFORE
UNIT IS AGAINST THE WALL.
37408-8-1020
OPTIONAL THERMOSTAT LOCATION
Figure 6
IF BRACKET IS INSTALLED
AFTER UNIT IS IN PLACE,
DRILL HOLE INTO CASING
SIDE AND ATTACH HERE.
PARTIAL VIEW OF
LEFT REAR CORNER
Figure 7
Wire Gauges - It is important to use wire of a gauge proper for the
length of the wire:
RECOMMENDED WIRE GAUGES
Maximum Length
1' to 10'
10' to 25'
25' to 35'
Proper operation depends on a good pilot flame. The flame must
cover the top of the thermopile. Cleaning of the pilot orifice and
burner may be required due to spiders.
System Check (Figure 8)
A millivolt meter is required to check the system. Millivolt readings
should be:
• Across the thermopile terminals, 400-450 millivolts with thermostat
OFF.
• Across the thermopile terminals, 150-250 millivolts with thermostat
ON.
• Across the thermostat wires at the valve, less than 30 millivolts
with thermostat ON.
• Across the thermostat wires at the thermostat, less than 5 millivolts
with thermostat ON. (Strong winds, dirty pilot and low pressure
will reduce readings.)
Piezo Pilot Ignitor Instructions
Depressing the red button completely causes a spark to occur at
the pilot. This is a substitute for a match which requires opening
the pilot hole cover.
To light the pilot, it is important that the electrode be 1/8" (3mm)
from the thermopile. The spark must occur at the point the burner
flame hits the thermopile. The end of the electrode will be red hot
with the pilot on.
On a new installation with air in the gas line, it is suggested that a
match be used. The match will light the pilot faster than the piezo
under this condition.
Wire Gauge
18
16
14
NOTE:
TO OPTIONAL
THERMOSTAT
IS CONNECTED
WITH WIRE NUT
FROM FACTORY.
DISCONNECT
TO ATTACH
THERMOSTAT.
Figure 8
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