Operating instructions
NNoottee::
During operation the heater continually senses the
input voltage from the batteries, if the input
voltage drops to approximately 10.5V (20V on a 
24 volt system) or rises above 15V (30V on a 24 
volt system) the heater will automatically shut 
down.
• When the heater is switched off, manually or automatically,
it starts a controlled cool down cycle.
• The fuel metering pump stops delivering fuel and the flame 
is extinguished.
• The combustion air blower and water pump continue to run
for 130 seconds to cool down.
• The heater shuts off.
The control unit, overheat sensor and flame sensor continually
monitor heater functions and will shut down the heater in case
of a malfunction.
• The control unit ensures electrical circuits (fuel pump,
combustion air blower etc.) are complete prior to starting 
the heater.
• If the heater fails to ignite within 90 seconds of the fuel 
pump being started, the starting procedure will be
repeated. If the heater again fails to ignite after 90 seconds
of fuel being pumped, a “no start safety shutdown” follows.
• If the heater flames out during operation, the heater 
automatically attempts to restart. If the heater fails to ignite 
within 90 seconds of fuel delivery, or ignites but flames out 
again within 10 minutes, “flame out” shutdown follows. After 
troubleshooting the problem, the heater can be started again 
by switching the heater off and then back on.
• Overheating due to lack of water, a restriction or a poorly 
bled coolant system results in an “overheat shut down”.
• If at any time the voltage drops below 10.5V (20V on a 24 
volt system), or rises above 15V (30V on a 24 volt system),
a “high/low voltage” shutdown follows (after a 20 second 
delay).
17
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Upon completion of installation prepare the heater as follows:
• Check all fuel, electrical and plumbing connections.
• Refill the engine coolant.
• Bleed air from the coolant system by running the engine 
and refilling the antifreeze as needed. Resecure heater hose.
• Run engine to further bleed the system
• Top up engine coolant.
Once switched on, the following sequence occurs:
• Control unit does a systems check ( flame sensor, 
temperature, safety thermal sensor and various other 
control unit checks).
• Water pump starts circulating coolant fluid.
• Combustion air blower starts.
• Glow pin begins to preheat 20-30 secs.
• After about 20-30 seconds the Fuel Metering Pump starts 
delivering fuel and the combustion air blower ramps up gradually.
• Once ignition takes place the flame sensor alerts the 
control unit and the control unit shuts off the glow pin
(ignition time: 1.5 - 2 minutes).
NNoottee::
If the heater fails to start the first time it will 
automatically attempt a second start. If
unsuccessful the heater will shut down completely.
NNoottee::
On initial start up the heater may require several 
start attempts to self prime the fuel system.
Once ignition is successful the following operations take place:
• Heater runs in full heat mode and the temperature is 
monitored at the heat exchanger.
• Once the coolant reaches 72°C (162°F) the heater will 
start to cycle down between levels (High,Medium,Low).
• If the coolant temperature continues to rise, the heater 
will automatically switch off. This occurs when temperature 
reaches 85°C (185°F).
• The water pump will continue to circulate coolant to allow 
the heater to monitor engine temperature
• The heater will automatically re-start once coolant
temperature reaches 68°C (154°F).
• The heater continues to run as described above until it is
switched off, either manually, automatically by a timer or 
heater malfunction shutdown.
NNoottee::
If the heater should flame out while in running 
mode, it will automatically attempt one restart. If 
successful it will continue to run, if not it will turn 
itself off.
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The heater must be switched off while any fuel tank 
on the vehicle is being filled.
The heater must not be operated 
in garages or  enclosed areas.
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