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SERVICE (cont.)

DILUTION SOLENOID VALVE

P1277.40

FIG. 10 DILUTION SOLENOID VALVE

Location:

Viewing the brewer from the rear the dilution so- lenoid is mounted on the center of the solenoid mount- ing bracket which is secured to the trunk base.

Test Procedure:

1.Disconnect the brewer from the power source.

2.With a voltmeter, check the voltage across the white/blue and white/violet wires on the dilution solenoid terminals when the ON/OFF switch is in the ÒONÓ position and the start switch is momen- tarily placed in the lower position. Connect the brewer to the power source. After the approxi- mate setting on the delay dial, the indication must be:

a)120 volts ac for two wire 120 volt models.

b)240 volts ac for two wire 240 volt models.

c)100 volts ac for two wire 100 volt models, re- main for the approximate setting on the dilution dial, and then return to its previous indication.

3.Disconnect the brewer from the power supply.

If voltage is present as described, proceed to #4.

If voltage is not present as described, refer to the Wir- ing Diagrams and check the wiring harness.

4.Remove both wires from the coil and check for continuity across the coil terminals.

5.Check the solenoid valve for coil action. Connect the brewer to the power source, place the ON/OFF switch in the ÒONÓ position and momentarily place the start switch in the lower position and release. Listen carefully after the approximate setting on the delay dial in the vicinity of the solenoid valve for a ÒclickingÓ sound as the coil magnet attracts and after the approximate setting on the dilution dial, repels the plunger.

6.Disconnect the brewer from the power source.

If the sound is heard as described and water will not pass through the solenoid valve, there may be a block- age in the water line before or after the solenoid valve or, the solenoid valve may require inspection for wear, and removal of waterborne particles.

If the sound is not heard as described, replace the solenoid valve.

Removal and Replacement:

1.Remove all wires from the solenoid valves.

2.Turn off the water supply to the brewer.

3.Disconnect the water lines to and from the sole- noid valves.

4.Remove the two 8-32 keps nuts holding the mounting bracket to the trunk base.

5.Lift out the bracket.

6.Remove the two 10-32 slotted-head screws hold- ing the solenoid valve to the mounting bracket.

7.Securely install the new solenoid valve to the mounting bracket.

8.Attach the mounting bracket to the trunk base.

9.Securely fasten the water lines to and from the solenoid valves.

10.Refer to Fig. 11 when reconnecting the wires.

WHI/VIO to Dilution WHI/GRN to Solenoid

Brew Timer TL4

WHI/VIO to Brew Solenoid WHI/VIO to Brew Timer TL1

WHI/BLU to Dilution

Timer TL4

BREW

WHI/VIO to Dilution

SOLENOID

Solenoid

BRN/WHI to Selector

If continuity is present as described, reconnect the white/blue and white/violet wires and proceed to #5. If continuity is not present as described, replace the solenoid valve.

DILUTION Switch

SOLENOID

SWEETENER

SOLENOID (Optional)

FIG. 11 SOLENOID VALVE TERMINALS

P1278

10225 031804

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Bunn TU3 service manual Dilution Solenoid Valve
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TU3 specifications

The Bunn TU3 is a renowned commercial coffee brewer known for its reliability and performance in bustling coffee shops, restaurants, and diners. Designed to cater to high-demand environments, the TU3 stands out with a variety of features that ensure an optimal brewing experience.

One of the primary characteristics of the Bunn TU3 is its capability to brew large volumes of coffee efficiently. It has a 3-gallon capacity, making it ideal for establishments that serve numerous customers throughout the day. This model can produce up to 19 gallons of coffee per hour, allowing establishments to keep pace with customer demand without sacrificing quality or flavor.

At the heart of the Bunn TU3's performance are its advanced brewing technologies. The brewer features a patented "multi-stream" spray head that evenly distributes hot water over coffee grounds, ensuring optimal extraction for a richer taste. This technology contributes to the consistent flavor profile that customers expect in a quality cup of coffee.

The TU3 is also equipped with a built-in hot water faucet, providing added convenience for brewing tea or instant beverages. Operators can easily access boiling water without interfering with the brewing process, streamlining service during peak hours. The adjustable temperature settings further enhance control over the brewing process, allowing for customization based on the coffee type or personal preference.

In terms of construction, the Bunn TU3 is built to withstand the rigors of commercial use. The brewer boasts a durable stainless steel body that is not only stylish but also easy to clean, helping maintain a professional appearance in any setting. Additionally, the brewer's design incorporates features such as a splash guard and easy-to-use controls, making it user-friendly for staff members.

Energy efficiency is another highlight of the Bunn TU3. Its innovative design helps in reducing energy consumption while still providing rapid brewing capabilities. This feature is particularly appealing to environmentally conscious operators looking to minimize their operational impact.

Overall, the Bunn TU3 coffee brewer combines speed, reliability, and exceptional brewing technology, making it a top choice for businesses that prioritize quality coffee service. Its combination of durability, efficiency, and user-friendly features ensures that it can handle the demands of any high-volume coffee operation, delivering excellent results cup after cup.
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