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1. Fan motor starts.
2. Fife (5) second delay.
3. Ignition spark and fuel switched on.
4. Wait for exhaust gas temperature to rises for min 15°C in 10 seconds. If the temperature is reached
sequence will continue, otherwise sequence will restart from the beginning for maximum of 4 times.
If the temperature level is not reached, the sequence will abort and fault indicator light will light up.
After failure is resolved, the sequence can be reset by pressing reset button for 2 seconds/until failure
indicator light will go off.
5. Wait for exhaust gas temperature to rises 10°C for maximum of 15 seconds. If the temperature is
reached, sequence will continue, otherwise re-ignition will take place maximum of 5 times. If the
temperature level is not reached, the sequence will abort and fault indicator light will light up.
6. After failure is resolved, the sequence can be reset by pressing reset button for 2 seconds/until failure
indicator light will go off.
STARTUP SEQUENCE
Heater cuts the fuel flow if determinate temperature has reached and performs exhaust gas
ventilation (10 sec).
Water runs normally through heater unit without warming. Blower starts automatically before ignition
transformer and solenoid ignited the heating process. WHU heating stays on until water flow is stopped or
unit is turned off.
Any time water flow is stopped the heater will stop after set delay provided the water flow be not restarted
within delay. After water flow is continued, WHU automatically starts ignition sequence.
Heater has equipped with the safety function, which stop heater immediately.
The failure indicator light will light up if one or several of the following conditions are met:
1. Water temperature >110°C.
2. Exhaust gas temperature Stays up and flame is on.
3. Exhaust gas temperature <300°C.
Fan motor has a 15 sec cooling sequence after burner has stopped.
SWITCH OFF SEQUENCE
WHU BURNING PROCESS
Water heating unit WHU110/200 -12V_24V
MAY CHANGE WITHOUT PRIOR NOTICE
November 2014 JLe