User manual

12433-7-0107
Page 10
These heating thermostats are specially designed for use on self-
generating systems. They should never be used on line or low
voltage A.C. circuits.
Exterior WallThe thermostat may be mounted on an exterior
wall above the heater if it is located in the same stud space as the
vent tubes and is a minimum of 6" (152mm) above the heater.
Interior Wall — The thermostat should be installed on an inside
wall away from the unit but in the same room.
It is important to use wire of a gauge proper for the length of the
wire:
RECOMMENDED WIRE GAUGES
Maximum Length Wire Gauge
1' to 10' 18
10' to 25' 16
25' to 35' 14
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
A millivolt meter is required to check the system. The millivolt
readings should be:
Across the thermopile terminals, 400-450 millivolts with ther-
mostat OFF.
Across the thermopile terminals, 150-250 milllivolts with ther-
mostat 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 mil-
livolts with thermostat ON. (Strong winds, dirty pilot and low
pressure will reduce readings.)
Piezo Pilot Ignitor Instructions
Depressing the piezo ignitor 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.
Figure 6