Bunn ES2SA Dosage Pulsometer Malfunction Alarm, Automatic Water Level Malfunction Alarm, Problem

BUNN Espress™

TROUBLESHOOTING

ES•2A™/ES•2SA™

Problem	Probable cause	Remedy
Brew cycle will not	Pump	When starting switch is pressed, pump
start (cont.)		should turn on immediately. If this dies not
		happen, check voltage at terminal block on
		the pump.. If correct voltage is present, use
		a flat-blade screwdriver to turn the motor
		shaft on the rear end of the motor to see if
		the pump itself is locked up. If the shaft
		dies no turn, replace pump assembly.
		Remove the solenoid valve and clear it of
		any obstructions. Rebuild or replace the
		valve if necessary.
	Start switch	Switch must make and break contacts.
		Check with ohmmeter for continuity.
Water is not hot or	Limit thermostat	Check continuity of limit with ohmmeter.
long recovery time.		Disconnect power supply and check across
		limit terminals. If no continuity, replace
		limit thermostat.
	Tank heaters	Check tank heater terminals for correct
		voltage. If voltage is present and machine
		is not heating properly, replace tank heater.
		A good tank heater will show continuity.

DOSAGE PULSOMETER MALFUNCTION ALARM

This alarm is activated if, for any reason, the pump is running and the metering pulses of the volumetric meter are not received by the central control unit, or when there is a time period longer than 5 seconds (approximately) between meter pulses. If an infusion unit is operating (pilot light on the push-button panel turned on), it will shut off and the pilot light will flash on and off. If this happens, the following should be checked:

-Possible obstruction at the coffee outlet (dirty injection head, blocked unit nozzles, etc.)

-Volumetric meter connections.

-Unit electrovalve.

-Unit electrovalve connections.

-Operation of volumetric meter.

-Possible pump malfunction.

To cancel the alarm, just press any push-button on the infusion unit push-button panel that has produced the alarm, however, if the malfunction continues, the alarm will be reactivated when the programmed doses push-button is pressed.

This alarm does not prevent the machine from operating in the continuous dosage mode.

AUTOMATIC WATER LEVEL MALFUNCTION ALARM

This alarm is activated when there is a demand for water but there is not enough water in the tank, and water level is not reached within a maximum prefixed time period in each tank, thus preventing a possible flooding of same. The pilot light on the push-button panel of the infusion units will flash on and off. If this happens, check the following:

• Water level sensor.	• Water level sensor connection.
• Water inlet (possible blockage of inlet).	• Tank water electrovalve.

This alarm does not prevent the machine from operating in the continuous infusion mode and will not be shut off even though the machine is disconnected from the electric supply line. Should this occur, the optical level should be checked by sight and water fed into the boiler manually.

To cancel the alarm after the problem has been solved, place the programming switch in the programming position, then simultaneously press the push-buttons for one short dose and 2 short coffee doses. Then after the alarm has been shut off, return the programming switch to the operating position.

Keep in mind that this alarm will surely be activated when filling a completely empty tank or with a very low water level (after repairs or commissioning of a new machine). To prevent the alarm from being activated, load the water manually.

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