Bunn U3 Coffeemaker User Manual


 
Page 8
PROBLEM
Brew cycle will not start
PROBABLE CAUSE
1. No water
2. No power or incorrect voltage to
the brewer
REMEDY
Water lines and valves to the brewer
must be open.
(A1) Check the terminal block for
120 volts ac across the red and white
terminals and the black and white
terminal on three wire 102/208 volt
or 120/240 volt models.
(A2) Check the terminal block for 208
volts ac, 230 volts ac or 240 volts
ac on "A Series" brewers across the
red and black terminals on two wire
single phase 208 volt, 230 volt and
240 volt models.
(A3) Check the terminal block for 208
volts ac, 240 volts ac, 380 volts ac
across the black and blue terminals,
the blue and red and the black and
red terminals on three wire three
phase 208 volt, 240 volt and 380
volt models.
TROUBLESHOOTING
A troubleshooting guide is provided to suggest probable causes and remedies for the most likely problems
encountered. If the problem remains after exhausting the troubleshooting steps, contact the Bunn-O-Matic
Technical Service Department.
Inspection, testing, and repair of electrical equipment should be performed only by qualied service person-
nel.
All electronic components have 120 volt ac and low voltage dc potential on their terminals. Shorting of
terminals or the application of external voltages may result in board failure.
Intermittent operation of electronic circuit boards is unlikely. Board failure will normally be permanent. If
an intermittent condition is encountered, the cause will likely be a switch contact or a loose connection at a
terminal or crimp.
Solenoid removal requires interrupting the water supply to the valve. Damage may result if solenoids are
energized for more than ten minutes without a supply of water.
The use of two wrenches is recommended whenever plumbing ttings are tightened or loosened. This will
help to avoid twists and kinks in the tubing.
Make certain that all plumbing connections are sealed and electrical connections tight and isolated.
This brewer is heated at all times. Keep away from combustibles.
WARNING Exercise extreme caution when servicing electrical equipment.
Unplug the brewer when servicing, except when electrical tests are specied.
Follow recommended service procedures
Replace all protective shields or safety notices
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