Tank Heater - Bunn TWIN APS Operating & Service Manual

SERVICE (cont.)
TANK HEATERS
FIG. 8 TANK HEATER
Location:
The tank heaters are located inside the tanks and
secured to the tank bottoms.
Test Procedures:
1. Disconnect the brewer from the power supply.
2. With a voltmeter, check the voltage across the red
wire from the terminal block and the black wire
from the control board. Connect the brewer to the
power source. The indication must be 240 volts
ac.
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 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.

NOTE- If the tank heater remains unable to heat,
remove and inspect heater for cracks in the sheath.
Removal and Replacement:
1. Remove the top cover or top warmer housing and
front access panel as previously described.
2. Disconnect the vent hose from the top of the tank
by pulling the elbow fitting from the grommet in
the top of the tank lid.
3. Drain water from the tank.
4. Disconnect the water supply tube to the dispense
valve from the side of the tank.
5. Disconnect the water supply tube to the solenoid
valve from the bottom of the tank.
6. If removing the left tank, on brewers with faucet,
P1855
disconnect the outlet water line to the faucet from
the side of the tank.
7. Disconnect the temperature probe and clip (black
lead) from the top of the tank by pulling the probe
from the grommet in the top of the tank lid.
8. Disconnect the pink wire from the level probe.
9. Disconnect the green wire from the top of the tank.
10. Disconnect the limit thermostat from the side of
the tank.
11. Disconnect the two white wires from the tank
warmer blanket.
12. Disconnect the black wire and red wire from the
tank heater terminals.
13. Remove the four #8-32 nuts securing the tank to
the mounting brackets and remove the tank as-
sembly.
14. Remove the eight #8-32 nuts securing the tank lid
to the tank.
15. Remove the two hex nuts securing the tank heater
to the bottom of the tank. Remove tank heater with
gaskets and discard.
16. Install new tank heater with gaskets to the bottom
of the tank and secure with two hex nuts.
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