Bunn TU3Q - Manual (Page 23)

Page 23
SERVICE (cont.)
TANK HEATER
FIG. 16 TANK HEATER
Location:
The tank heater is located inside the tank and se-
cured to the tank lid.
Test Procedures:
1. Disconnect the brewer from the power supply.
2. With a voltmeter, check the voltage across the
black and white wires on 100 volt and 120 volt
models or the black and red wires for 230 volt
models. Connect the brewer to the power source.
The indication must be:
a) 120 volts ac for two wire 120 volt models.
b) 230 volts ac for two wire 230 volt models.
c) 100 volts ac for two wire 100 volt models.
3. Disconnect the brewer from the power source.
If voltage is present as described, proceed to #4
If voltage is not present as described, refer to the
Wiring Diagrams and check wiring harness.
4. Disconnect the black wire and the white wire or
red wire from the tank heater terminals.
5. Check for continuity across the tank heater termi-
nals.
If continuity is present as described, reconnect the
wires, the tank heater is operating properly.
If continuity is not present as described, replace the
tank heater.
P2200.50
FIG. 17 TANK HEATER TERMINALS
P1284.80
BLK to Control
Thermostat
WHI to Power Cord
(100/120V)or
RED to Thermal Fuse
(230V)
10288 110503
NOTE: If the tank heater remains unable to heat, re-
move and inspect heater for cracks in the sheath.
Removal and Replacement:
1. Disconnect the black wire and the white or red
wire from the tank heater terminals.
2. Remove sprayhead and the hex nut securing the
sprayhead tube to the hood. Set aside for reas-
sembly.
3. Disconnect vent tube and water inlet tube.
4. Remove the six #10 thread cutting screws secur-
ing the tank lid to the tank.
5. Remove the tank lid with limit thermostat, spray-
head tube, tank heater and vent tube.
6. Remove the two hex nuts securing the tank heater
to the tank lid. Remove tank heater with gaskets
and discard.
7. Install new tank heater with gaskets on the tank
lid and secure with two hex nuts.
8. Install tank lid with limit thermostat, sprayhead
tube, tank heater and vent tube using six #10
thread cutting screws.
9. Secure sprayhead tube to hood using a hex nut.
10. Install sprayhead.
11. Connect vent tube and water inlet tube to fitting.
12. Reconnect the wires to the limit thermostat, tank
heater. See limit thermostat section in this manual
when reconnecting wires.
13. Refer to Fig.17 when reconnecting the tank heater
wires.