ADAPTER
INLET
BUSHING
GROUND LEAD
VALVE GROUNDING AND
ATTACHMENT SCREW
INJECTOR
BODY
ADAPTER
GAS CONTROL
VALVE
GAS CONTROL VALVE
1. Disconnect the heater from its electrical supply.
2. Close fuel supply valves to heater.
3. Remove dust filter and filter sleeve.
4. Brush or blow off any dust in vicinity of gas control
valve.
5. Disconnect the gas hose from hose adapter at inlet of
gas control.
6. Using the appropriate wrench, remove bushing with
hose adapter from control valve inlet. See Fig. 14.
7. Using appropriate wrenches, hold the gas valve
adapter at the outlet of the gas control in place while
loosening the control valve body from the adapter.
8. Remove the control box cover.
9. Loosen the nut of the water tight connector through
which the ground and power supply leads of the
control valve pass.
10. Disconnect the valve’s electrical leads from the
ignition module.
11. Route the valve leads individually through this
connector.
12. Save the water tight connector nut from the valve
leads. This same nut will be slid over the leads of the
replacement valve and used to create a water tight
connection at the control box.
13. Loosen the screw at the injector body and disconnect
the valve’s electrical leads. See Fig. 14.
FIG. 14
14. Reverse these procedures for valve installation.
17
WARNING
Fire H
Hazard
■
Do not operate the heater with the high limit switch
bypassed.
■
Operating the heater with a bypassed high limit switch
may lead to overheating, possibly resulting in a fire,
with subsequent damage to the heater, building
damage, or loss of livestock.
TERMINAL
MOUNTING LEG
RESET BUTTON
SENSING SURFACE
FLAME
ATTENTION
■
This heater is equipped with a manual reset high limit
switch. Its purpose is to disconnect the electrical
supply to the ignition control board in the event of an
overheat condition.
■
An overheat condition is normally caused by:
-- Excessive fuel gas pressure
-- Heater not being routinely cleaned
-- Heater not properly hung. (Control end is 1º to 5º
down from horizontal. See page 8.
The high limit switch should be tested a minimum of once
per year or anytime the heater is taken down for servicing.
Refer to the following testing instructions.
1. Disconnect the heater from its electrical supply.
2. Remove the high limit switch from the control box.
3. Holding the switch by one of its mounting legs, apply
a small flame only to the sensing portion on the back
of the switch. Be ccareful nnot tto m
melt tthe pplastic
housing oof tthe sswitch w
when cconducting tthis ttest.
4. Within a minute, you should hear a “pop” coming
from the switch, which indicates the contacts of the
switch have opened.
5. Allow the switch cool down before firmly pressing the
reset button on the switch.
6. Check for electrical continuity across the switch
terminals to make sure the contacts have closed.
7. Reinstall the switch back into the heater. Reconnect
the heater to its electrical supply. Start the heater
and check for proper operation.
FIG. 13
HIGH LIMIT SWITCH
Summary of Contents for I17
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