Bunn TWIN Coffeemaker User Manual


 
Page 15
TROUBLESHOOTING (cont.)
Water does not heat to proper
temperature (cont.)
IMPORTANT: Make sure no tem-
perature tests are taken before the
ready light is "ON". Tank tempera-
ture must be stabilized before read-
ings are taken.
Spitting or excessive steaming
4a. Temperature Probe (CDBC)
4b. Temperature Probe (CEZ)
5. Limit Thermostat (CDBC & CEZ)
6. Tank Heater (CDBC & CEZ)
1. Lime build up on temperature
probe, tank or tank heater
A) Remove the probe from the
grommet and submerge in a water
bath of approximately 70°F(21°C).
Connect an ohmmeter to pins 3
and 4 of the J3 connector. At
60°F(16°C) the reading should be
15.3k ± 2k OHMS, at 70°F(21°C)
the reading should be 11.8k ± 2k
OHMS, and at 80°F(27°C) the read-
ing should be 9.3k ± 2k OHMS. If
the probe is within these param-
eters, reconnect the J3 plug to the
control board.
B) Remove the probe from the
grommet and submerge in a water
bath of approximately 70°F(21°C).
Connect an ohmmeter to pins 2
and 3 of the J5 connector. At
60°F(16°C) the reading should be
15.3k ± 2k OHMS, at 70°F(21°C)
the reading should be 11.8k ± 2k
OHMS, and at 80°F(27°C) the read-
ing should be 9.3k ± 2k OHMS. If
the probe is within these param-
eters, reconnect the J5 plug to the
control board.
Disconnect the brewer from the
power source. Check for continu-
ity across the limit thermostat ter-
minals. Continuity should be
present. If not replace the limit
thermostat.(See page 28)
Disconnect the brewer from the
power source. Check for continu-
ity between the white terminal of
the terminal block and the black
wire on the relay on the control
board. There should be a low OHM
reading. If no continuity is present,
check for a wiring problem, then
replace the tank heater if no wiring
problem is found.(See page 29)
Inspect probe and tank assembly
for excessive lime deposits. Delime
as required.
PROBABLE CAUSE
REMEDY
HEATING CIRCUIT
PROBLEM
29319 091203