Blue Bird Coachworks 450 LXi, Owner'S Manual

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4-8 Heating Systems
450 LXi Owner Manual
~ 4-8-2 ~ Rev. “C”
4-8.2 Operation
4-8.2.1 Starting the Heater
The major steps in starting the heater are as follows:
Turn on the ON/OFF control switch, located on the remote indicator panel.
Turn up the zone thermostat to a setting higher than room temperature.
Start the heater by switching the service switch to ON. This switch is located on the side of the electronic control box
located next to the unit in the bay.
4-8.2.2 Signs of Normal Operation
When the heater is operating normally:
The ignitor will glow and the combustion air intake fan and the circulating pump begin to run. Whenever the pump is
running, the green LED at the bottom of the LED display will be on.
A few seconds later, the fuel pump starts delivering fuel to the regulator, the compressor turns ON, the fuel valve opens,
and fuel is drawn to the air aspirating nozzle. The fuel is atomized and sprayed into the combustion chamber to start
combustion.
After the ignition period (about 10 seconds), the ignitor shuts OFF, and the burner continues to operate. The heater will
operate until all the zone thermostats are satisfi ed, or until the heater reaches its normal water operating temperature
of 180°F. Once the normal operating temperature is reached, the burner itself will cycle off and the combustion fan will
operate for an additional two minutes to purge the burner. If a zone thermostat, domestic water heater aquastat, or engine
heat exchanger aquastat is not satisfi ed, the circulating pump will continue to operate. If a thermostat cannot be satisfi ed by
the residual heat in the system, and the water temperature drops, the burner will restart and cycle until all thermostats are
satisfi ed. Once all thermostats are satisfi ed, the heater will go through the two minute purge, and the circulating pump will
ease. The circulating pump will operate if the remote switch and any zone thermostat or the domestic water aquastat are on.
The circulating pump will be activated independently by the engine heat aquastat. After the heater has been running for a
little while, the water outlet of the heater case should become warm. If the water hose leaving the outlet of the heater does
not warm up immediately after the pump comes on, water is not circulating properly and air may be in the system. Turn the
heater OFF immediately and check water circulation, refer to
Water Filling Procedure Section later in this manual.
4-8.2.3 Main Control Board Operation
Once the heater is operating normally, you must check the operating safety functions of the main board. To make sure the
safety functions work properly, place your hand over the air intake inlet to the compressor, this will snuff out the fl ame. If
you continue to block the air intake inlet, the heater will try to restart two more times and failing to do so will shut it down,
stopping the compressor and fuel pump. The board will display a code 7. Reset the fault and the heater will continue with
normal operation.
4-8.2.4 Stopping the Heater
(For Seasonal Purposes)
WARNING!!! NEVER shut off the power to the heater using the circuit breaker or a master switch, or disconnect
the battery while the heater is running. Doing so will cause serious damage to the heater, which will not be covered
under warranty.
To turn the Heater OFF, turn OFF the ON/OFF control switch, located on the remote indicator panel. The room thermostat or
the remote indicator panel ON/OFF switch can be turned ON or OFF at any time, without harming the heater. The heater will
automatically run through the purge cycle, which takes about two minutes.
4-8.2.5 Stopping the Heater
(For Maintenance)
To shut down the heater totally, for maintenance purposes:
Turn OFF, the ON/OFF control switch, located on the remote indicator panel.
Turn OFF, the service switch on the electronic control box.
Wait until the heater has completed the purge cycle and turned itself OFF.
Disconnect the power supply.
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