Bunn service manual Initial Setup, Start-Up, BUNN Espress, ES2A/ES2SA

BUNN Espress™

INITIAL SETUP

ES•2A™/ES•2SA™

START-UP

Retighten the tank cover bolts, nuts, flat section strips, tank heaters, and the individual tank section lids (at upper part of the tank). Fill the tank with water to the optimum water level zone (N) using the water feed tap. In the models with and electronic water level control fill the tank to the minimum water level zone (-).

Connect the electrical system.

Turn on the toggle switch located on the base (left side bottom). The indicator lamp on the front of the base (left side) will light up. When the toggle switch is turned on, in the model with an electronic water level control, the electronic water level operation pilot light will light up, start the pump set and open the water inlet valve (located inside the machine) introducing water into the tank until it reaches the optimum water level zone

(N).

NOTE: During the initial fill of the tank, if manual fill is not used and automatic is filling the tank, the alarm condition will arise (during re-fill no water goes through the flowmeter). Refer to “DOSAGE PULSEMETER MALFUNCTION ALARM” in the TROUBLE SHOOTING section in this manual for further instruction.

When the water makes contact with the sensor probe, this will close the inlet valve, shut off the pump set, and disconnect the pilot light.

While waiting for the machine to reach working pressure (tank pressure gauge), check and adjust the pump set as on page 4.

When the tank and the pump pipes are filled, press the “continuous doses” push button on each set and the pumping unit will immediately start injecting water into the corresponding tank section and tube leading to the units until water begins to flow through them. This indicates that air has been bled from the hydraulic circuit and the push-buttons can be pressed again to shut off the pump.

Before the tank pressure reaches 1.2 bar, air must be bled from inside the tank as described on page 4. When the tank pressure gauge indicates 1.2 bar, the electrical pressure switch will disconnect. If this does not occur at the mentioned pressure, adjust the pressure switch (page 29 figure 1), placed inside the machine on the right side, using the inside adjustment screw. Tightening the screws lowers the tripping pressure and

vice-versa.

When the water in the individual tank sections and hydraulic circuit expands do to heating, the water pressure gauge reading will exceed 8-9 bar working pressure, and when the pressure reaches 11 bar the pressure release valve will open to release said pressure. If not, the inside nut (page 19 figure 13) must be adjusted so that it discharges the pressure at an indicated pressure of 11 bar.

Place a dose of ground coffee (approx. 6 grams) in the cup of the filter-holder and after lightly tamping the coffee, and wiping the rim free of any excess grounds, place the filter holder in the group head unit.

Turn on the push button control (red button) and all the mechanisms of the unit will begin operating, Let it run about 30 seconds and observe the pump feed pressure.

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