Bunn BrewWise DBC Service Manual page 10

TROUBLESHOOTING (cont.)
Power
Water flows into tank continuously
with power applied to brewer.
Water will not heat or display shows
HEATING TIME TOO LONG
Possible Cause
1. Refill Probe or Sensitivity Set-
ting
2. Electronic Control Board
1. Limit Thermostat
CAUTION - Do not eliminate or
bypass limit thermostat. Use only
replacement part #23717.0003.
2. Tank Heaters
Page 10
Troubleshooting Procedures
Check the sensitivity setting. Refer to
Refill function. If the left three digit
number is less than the right number,
the machine "thinks" it is full and the
refill valve should be off. If the left
number is larger than the right, then
the refill valve will automatically be
turned on to fill the tank. The right
number is the threshold setting and
can be adjusted to compensate for
extreme water conditions: very pure,
low conductance water requires a
higher setting, while high mineral
content, high conductance water
requires a lower setting. Note that
the left number changes from a high
value when water is NOT touching
the refill probe to a low value when
water IS touching the probe. For best
operation, the right number should
be set to a value midway between
these low and high numbers. Before
changing the setting, confirm that the
refill probe is free of scale buildup
and the connection to it is secure.
Substitute a control board known to
be in good working order.
Remove power from the brewer.
Press reset button on limit ther-
mostat. Then check for continuity
through it.
Remove power from the brewer.
Check for continuity through the
tank heaters.
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