Hurricane SCH25, Service And Troubleshooting Manual

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1. The combustion fan will turn ON and run for 20 seconds.
2. The igniter will turn ON and the combustion fan will turn OFF.
3. The igniter will glow for 10 seconds to allow it to reach ignition
temperature.
4. After the igniter has been glowing for 10 seconds, the air compressor,
fuel pump, fuel solenoid and combustion fan will turn ON.
5. The air compressor provides a constant air supply to the nozzle under
a specific pressure and flow rate. The air is filtered before it enters
the compressor. In the nozzle the compressed air is guided over the
tip of the nozzle where it creates a negative pressure in the centre
tube. This negative pressure is used to draw fuel from the fuel
regulator. All fuel lines from the regulator to the nozzle must be
airtight. Any leaks will have an adverse effect on the flame. The
nozzle produces a solid cone spray pattern with extremely fine
particles of fuel. This spray is then ignited when it makes contact
with the igniter.
6. The fuel pump pumps fuel from the fuel tank up to the fuel regulator.
Before the fuel enters the fuel pump, it should pass through an
external filter. There is also an internal filter between the fuel pump
and the fuel regulator. Fuel is only allowed to pass the regulator
when there is a negative pressure between the regulator and the
nozzle. In between the fuel regulator and the nozzle is a fuel
solenoid. This fuel solenoid prevents the fuel being drawn back from
the nozzle when the burner is off. This allows for a clean ignition.
7. The combustion fan draws outside air. This is used to create a forced
air flow through the combustion chamber. This is for optimal
combustion and to exhaust the combustion gases through an exhaust
pipe system into the atmosphere.
8. After ignition takes place, the igniter will remain ON for an additional
5 seconds. This is so if there are any air bubbles in the fuel system,
the atomised fuel will continue to be ignited.
9. After 5 seconds, the igniter will turn OFF and the air compressor, fuel
pump, fuel solenoid and combustion fan will remain ON. At this point
the flame sensor will also look for a flame.
10.The burner will continue to run until one of the following occurs:
1. The coolant inside the heater reaches the set operating
temperature range
2. The heater is switched off
3. One of the components faults
4. A flame out occurs
5. A voltage fault occurs
Note: After any of the above situations, the combustion fan will run for
2 minutes to purge exhaust gases from the system. The only time the
combustion fan will not run after the system cycles or faults is when the