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Premier Ductable Heater
www.lbwhite.com
Owner’s Manual • Premier Ductable Heater
20
Manual Reset High Limit
Switch
Premier 40 has one high limit switch; located directly below
the burner on the underside of the heat chamber.
Premier 80/170 has two limit switches, one inside the solid
door end on the heater chamber, the other inside the lou-
vered door end mounted on the fan housing side panel.
The high limit switches can be easily identified by a red
reset button in the center of the switch See FIG. 20 & 21,
Premier 170 shown.
FIG. 20
FIG. 21
WARNING
Fire Hazard
■ Do not operate the heater with the high limit
switch bypassed.
■ Operating the heater with the high limit switch
bypassed or jumper-ed may lead to overheating,
possibly resulting in a fire, with subsequent
damage to the heater or property damage.
Reset Button
Sensing Surface
Terminal
Flame
Mounting Leg
Function
If the heater overheats, the high limit switch can trip,
opening the electrcial circuit to the gas control valve.
Overheating is generally caused by duct restrictions,
low voltage, blocking the heater’s air inlet, or excessive
gas pressure.
Resetting
If the high limit switch trips; remove the red cap and
firmly press the reset button in the middle of the switch.
Then, shut the heater off and turn it back on. Determine
the cause of the limit tripping.
Testing
To ensure proper function of this critcal safety
component, test the switch annually, typically when the
heater is given a thorough cleaning.
1. Remove the high limit switch from the heater.
2. With a pliers hold the switch by one of its mounting
legs, apply a small, soft flame only to the sensing
portion on the back of the switch. See Fig. 22. Be
careful not to melt the plastic housing of the switch
when conducting this test.
3. Within a minute, you should hear a click coming from
the switch, indicating the contacts of the switch have
opened.
4. Allow the switch cool down for about a minute.
Remove the red cap and firmly press the reset button
on the switch.
5. Check for electrical continuity across the switch ter-
minals to make sure the contacts have closed. Install
the red cap; reinstall back into the heater and connect
the wires to the terminals.
FIG. 22
High Limit
High Limit