Blue Bird Coachworks 450 LXi, Owner'S Manual

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450 LXi Owner Manual 4-8 Heating Systems
Rev. “C”
~ 4-8-1 ~
4-8 Heating Systems
There are three different heating systems in your coach. The Webasto hydronic heating system circulates a glycol-water
mixture throughout the coach. The Operator can control four heating zones which direct the heat where it is needed. Further
explanations of its operation and its advantages are discussed later in this section. The second heat source is a set of four
heat pumps that are part of the Dometic roof top air conditioning units. These heat pumps provide heat at temperatures
above 42°F. The third source of heat is four 120VAC electric heaters - two 1000 watt heaters are installed in the bathroom
and kitchen, two 500 watt heaters are installed in Bay 2 and Bay 4.
4-8.1 Webasto Hydronic Heating System
Hydronic heating is comprised of a 50/50 water, antifreeze mixture that is ran through piping in the coach and continuously
heated. There are zones placed throughout the coach that have fans attached to them. Using the two thermostats that are
installed in the coach a user can control the heat zones for the coach. One thermostat controls the front of the coach and the
other controls the back. The dividing line is the fi rst pocket door at back of galley. The thermostats are located in the bedroom
area and the front main galley area. This system is run off of the diesel and it may be preferred to use the 110 electric
heating system when parked in a campground to save diesel provided the weather isn’t too inclement. Some advantages of
the hydronic system are:
Continuous hot water
Fuel effi cient burner which burns all grades of diesel fuel, stove oil, furnace oil, and kerosene without any burner
adjustments (not for use with gasoline.)
Zero smoke, no carbon built-up, no fouling or smell.
Copper and brass water jacket transfers more heat to the water and reduces the fuel consumption (three year warranty).
High temperatures 310 stainless steel burner and marine stainless steel jacket.
Quiet operation and low power consumption.
All heaters are designed to operate on 10.5 to 15.0 V.D.C.
All heaters are electric ignition, which draws 2 amps for 30 seconds on startup.
Insulated enclosure for retaining heat and minimizing noise.
Sealed combustion – 100% outside air is fan assisted to the combustion chamber and then exhausted outside, avoiding
backpressure.
Optional bottom exhaust – mostly used in motor homes.
Includes four zone heating control for up to four thermostats.
Completely modular and fi eld serviceable (user friendly).
Hookups and connections are easily accessible.
Electronically controlled. Safety features include four-second shutdown in case of failure, LED digital readout on the
electronic control panel for indicating faults, aquastats for monitoring water temperatures and a photodiode to monitor
the fl ame.
Complete with remote control panel with ON/OFF reset button, LED digital readout, and signal horn.
Jumper for constant pump circulation (Automatic cycling when off).
All heaters cycle at an operating temperature of 180°F (82°C) with overheat cutout set at 195°F (90.5°C).
Air accumulator installed in the fuel line to collect air bubbles and prevent them from reaching the burner and causing
nuisance shutdowns.
The Webasto heater utilizes a low pressure fuel system. The built in fuel pump draws fuel from the fuel tank up to a zero
pressure regulator where it stops. An air accumulator is installed inline between the fuel pump and the regulator to trap any
air bubbles from passing through the nozzle valve. For continuous bleeding, a return line can be run back to the fuel tank.
A small compressor delivers air to an air aspirating nozzle. This nozzle draws fuel from the zero pressure regulator, mixing
it with air through a venturi. This process produces a very fi ne mist of fuel into the burner providing complete combustion
and very low emissions. This low pressure system allows the use of a larger fuel orifi ce, less clogging, less wear and less
maintenance. Ignition is accomplished by a low draw ignitor, approximately 2 amps, for thirty seconds. Combustion air is
drawn from outside so the heater can be installed in an air tight compartment or in the engine room without the fear of
starving the heater of air or back venting the heater with the engine running.
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