6
Controls water heater burn process according to the measured exhaust gas and water output temperatures
and water flow sensor.
If at any time water flow is stopped the burner will stop after a delay of 4 seconds if the water flow is not
restored within that time.
Burner will stop immediately and the failure indicator light will start indicating if one or several of the following
conditions is met:
A. Water temperature >110C (Alarm 3),
B. Exhaust gas temperature > 300C (Alarm 4),
C. Exhaust gas temperature drops more than 15°C after burning sequence has started (Alarm 2), if
ignition sequence has failed (Alarm 1), or if emergency stop button has been pressed indicator light
burns continuously. See TABLE 1.
After failure is resolved, Press the Reset button for 2 seconds to reset the fault.
Fan motor has a 15 seconds cooling sequence after burner has stopped.
WHU BURNING PROCESS
Alarm 1 0.5s/0.5s
Alarm 2 1s/1s
Alarm 3 2s/1s
Alarm 4 3s/1s
Emergency Stop
Continues
ALARM SEQUENCE TABLE 1.
Water heating unit WHU110/200 -12V_24V
MAY CHANGE WITHOUT PRIOR NOTICE
November 2014 JLe