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1. Shut off gas supply to heater inlet.
2. Disconnect heater from electrical power source.
3. Let the heater cool down so pilot assembly is cool to
touch.
4. Remove upper screw on pilot assembly. Loosen, do
not remove, lower screw.
5. When loosened, pull up on the pilot shield, thereby
exposing the pilot bracket, pilot orifice, and
thermocouple.
6. The thermocouple is located to the right of the pilot
orifice secured in place to the pilot bracket by either
a push-in mounting clip or attachment nut.
7.
To remove the thermocouple from the bracket, simply
pull down on the thermocouple's copper tubing, or if
the thermocouple uses an attachment nut, loosen
FIG. 11
THERMOCOUPLE
TIP
GAS VALVE
Fire H H azard
Do not operate the appliance with the high limit switch
bypassed.
Operating the heater 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.
The high limit switches should be tested a minimum of once
per year when the heater is given a thorough cleaning.
1. Disconnect the heater from its electrical supply.
2. Remove the high limit switch from the heat chamber.
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 c c areful n n ot t t o m m elt t t he p p lastic h h ousing
of t t he s s witch w w hen c c onducting t t his t t est.
4. Within a minute, you should hear a "pop" coming from
the switch, which indicates the contacts of the switch
have opened.
PILOT ASSEMBLY
OPTIONAL ATTACHMENT NUT
THERMOCOUPLE LEAD
WARNING
the nut (turn counterclockwise) until the nut is
entirely out of the pilot bracket.
8. Loosen and remove the lead connector nut threaded
into the power unit on the gas control valve.
9. To assemble, reverse above procedure.
If your thermocouple has a push-in mounting clip, make sure
on reassembly that the thermocouple is pushed in completely,
as far as it can go, into the pilot bracket. Failure to do so may
cause pilot outage problems.
When threading the thermocouple's connector nut back into
the gas control valve, thread the nut in finger tight and snug it
in place. DO NOT OVERTIGHTEN OR USE UNNECESSARY
FORCE ON THE NUT WHEN TIGHTENING.
Do not use pliers when removing or replacing the
thermocouple. Doing so will round off the attachment nuts,
making servicing difficult later on. Always use a wrench.
POWER UNIT
THERMOCOUPLE LEAD
CONNECTOR NUT
POWER UNIT
CONNECTOR CONTACT
5. Allow the switch cool down for about a minute 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. 12
RESET BUTTON
TERMINAL
MOUNTING
LEG
THERMOCOUPLE
IMPORTANT
TESTING MANUAL RESET
HIGH LIMIT SWITCH
SENSING
SURFACE
FLAME
17
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