Bunn TWIN APS, Operating & Service Manual

Page: 11 / 32

Page 11
Will not fill or refill
Fill or refill does not shut "OFF"
(ON/OFF Switch "ON")
PROBABLE CAUSE REMEDY
PROBLEM
1. Power off to brewer
2. Water shut off
3. Display flashing
4. ON/OFF Switch
5. Lime build up on Probe
6. Refill Valve or Control Board
7. Water is too conductive for proper
operation when using the factory
setting of sensing threshold
1. Lime build up on probe
Press ON/OFF switch on control
panel to determine if power is "ON".
Make sure water is ON.
Brewer has shut down due to mal-
function (See Diagnostic Chart in
manual, Page 20, or under top lid of
brewer).
Make sure ON/OFF Switch is "ON"
and indicator is lit.
Remove the Probe and check for
lime deposit on tip. Clean and rein-
stall.
Disconnect the brewer from the
power source and remove wires
from refill valve coil. Check for con-
tinuity across the terminals of the
solenoid coil. If continuity is not
present, replace the refill valve (See
page 28). If continuity is present,
the coil may be stuck closed. Shut
water off to brewer. Set the ON/OFF
switch to the "OFF" position. Open
the faucet and drain water down in
the tank until flow stops or slows to
a trickle. Attach a voltmeter to the
terminals of the refill solenoid. Con-
nect the brewer to the power source.
Press the switch "ON". Within five
seconds, voltage should be present
at the solenoid terminals. If voltage
is not present, refer to the wiring
diagrams and check the wiring har-
ness.
Reset the
Water Sensing Threshold
Adjustment Procedures on page 8.
Remove Probe and check for lime
deposits on tip. Clean and reinstall.
TROUBLESHOOTING (cont.)
REFILL CIRCUIT
36672 030104