Service manual
Page 8
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 qualied 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 specied.
    •  Follow recommended service procedures
    •  Replace all protective shields or safety notices
PROBLEM
Brew cycle will not start (CT, 
CTF, CWT, CWTA, CWTB, CWTF, 
CWTFA, CWTFB, SINGLE CW & 
SINGLE CWF)
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 across the black and 
white terminals on two wire 120 
volt brewers.
(A2) Check the terminal block 
for 120 volts across the red and 
white terminals and the black 
and white terminals on three wire 
120/240 volt brewers.
(A3) Check the terminal block for 
200 volts on "B Series" brewers 
or 230 volts on "A Series" brew-
ers across the red and black 
terminals.
(B) Check circuit breakers or 
fuses.
10841 020503










