Tank Heater(S) - Bunn CWT-APS-DV Operating & Service Manual

SERVICE (cont.)
TANK HEATERS
FIG. 12 TANK HEATERS
Location:
The tank heaters are located inside the tank and
secured to the tank lid.
Test Procedures:
With Voltage selector switch set to 120V:
1. Disconnect the brewer from the power supply.
2. With a voltmeter, check the tank heater voltage
across the white wire from the terminal block and
black wire from the tank heater. Connect the
brewer to the power source. The indication must
be 120V ac.
If voltage is present as described, proceed to #3
If voltage is not present as described, refer to the
Wiring Diagrams and check wiring harness.
With Voltage selector switch set 208-240V:
1. Disconnect the brewer from the power source.
2. Check voltage across the red wire from the termi-
nal block and black wire from the tank heater.
Connect the brewer to the power source. The
indication must be 208/240 volts ac.
5. Disconnect the brewer from the power source.
If voltage is present as described, proceed to #3
If voltage is not present as described, refer to the
Wiring Diagrams and check wiring harness.
3. Disconnect the black and blue wires or the red and
white/violet wires from the tank heater terminals.
4. Check for continuity across tank heater terminals.
If continuity is present as described, reconnect the
wires, the tank heaters are operating properly.
If continuity is not present as described, replace the
open tank heater.
NOTE- If the tank heater(s) remain unable to heat,
remove and inspect heater(s) for cracks in the sheath.
Removal and Replacement:
1. Disconnect the water supply tube from the fill
basin.
2. Remove the tank inlet fitting securing the fill basin
to the tank lid, remove fill basin, splash guard and
tank inlet gasket. Set all parts aside for reassem-
bly.
P2759.40
3. Turn off water supply to the brewer and disconnect
the inlet and outlet water lines to the faucet coil
assembly.
4. Disconnect the black wire on the limit thermostat
from the tank heater switch. Disconnect the blue
wire from the limit thermostat to the control ther-
mostat.
5. Disconnect the black, red, white/violet and blue
wires from the tank heater terminals.
6. Remove sprayhead and the hex nut securing the
sprayhead tube to the hood. Set aside for reas-
sembly.
7. Remove the eight #8-32 nuts securing the tank lid
to the tank.
8. Remove the tank lid with limit thermostat, spray-
head, tank heaters and coil assembly.
9 Remove the two hex nuts securing each tank
heater to the tank lid. Remove tank heater(s) with
gaskets and discard.
10. Install new tank heater(s) with gaskets on the tank
lid and secure with two hex nuts.
11. Install tank lid with limit thermostat, sprayhead
tube, tank heaters, coil assembly using eight #8-
32 hex nut.
12. Reconnect the inlet and outlet water lines to the
faucet coil assembly.
13. Secure sprayhead tube to hood using a hex nut.
14. Install sprayhead.
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