Operating Instructions
Remove the front door. If you smell gas,
STOP
. Follow
listed safety instructions. If you do not smell gas, fol-
low the next steps.
1. Turn on all electric power to appliance.
Fig. 36: Condensate Float Switch
Condensate Float Switch
The heater is equipped with a condensate float switch
to prevent operation when the condensate water level
is too high. The heater shutting down from the conden-
sate float switch is indicative of a blocked drain or
problem with the condensate management system.
The condensate float switch is located inside at the left
rear of the heater, and can be accessed through the
back panel.
Operation of either the High or Low Gas Pressure
Switch will turn on an LED inside the switch housing.
Push the top of the plastic switch housing as shown in
Fig. 34 to reset a tripped pressure switch. The LED will
go out when the switch is reset.
Blocked Vent Switch
The heater is equipped with a blocked vent pressure
switch to prevent the operation of the boiler when a
significant amount of air flow is blocked at the vent.
The switch is located at the left rear of the unit.
Fig. 35: Blocked Vent Switch
37
Thermal Fuse
The heater is equipped with a thermal fuse located at
the back of the combustion chamber. The thermal fuse
shuts down the boiler if the temperature rise within the
combustion chamber becomes excessive. If the boil-
er shuts down due to the thermal fuse, call your local
representative or the factory. A qualified service tech-
nician must evaluate the condition of the combustion
chamber before replacing the fuse.
Burner Door Limit
The heater is equipped with a fixed setting manual
reset high limit temperature device on the burner door.
The limit is an additional safety that shuts down the
boiler if the temperature rise within the combustion
chamber becomes excessive. If the boiler shuts down
due to the burner door limit, call your local representa-
tive or the factory. A qualified service technician must
evaluate the condition of the combustion chamber
before resetting the limit.
THERMAL FUSE
Fig. 37: Thermal Fuse
BURNER DOOR LIMIT
Fig. 38: Burner Door Limit
Summary of Contents for 300A
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