Tank Heaters - Bunn Axiom Series Service & Repair Manual

TANK HEATERS

Location:
The tank heaters are located inside the tank and secured
to the tank bottom.
Test Procedures:
1. With a voltmeter, check voltage across the white
wire (120V Models) or red wire (120/208-240V
Models) from the terminal block and black wire
from the control board. Connect brewer to the
power source. The indication must be 120 volts
ac for two wire 120 volt models or 208-240 volts
ac for three wire 120/208-240 volt models (during
a heating cycle).
2. 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. If harness
checks ok, replace control board.
3. Disconnect the wires from the tank heater termi-
nals.
4. Check resistance value across tank heater terminals
and compare to chart.
If resistance is present as described, reconnect the
wires, the tank heater is ok.
If resistance is not present as described, replace the
tank heater.
NOTE- If any resistance is read between sheath and
either terminal, remove and inspect heater for cracks
in the sheath.
HEATER
1425W-120V
3500W-240V
1850W-240V
3500W-200V
3000W-240V
2268W-240V
TERMINAL TO SHEATH - INFINITE (OPEN)
RESISTANCE
10.10
16.46
31.14
11.43
19.20
6.35
Page 20
2268W
Large
Dia.
FIG. 20-1 DV TANK HEATERS
Removal and Replacement:
1. Remove the top cover or top warmer housing and
front access panel as previously described.
2. Drain water from the tank.
3. Disconnect all the hoses from the tank.
4. Disconnect the temperature probe from the top of
the tank by pulling the probe from the grommet in
the top of the tank lid.
5. Remove both level probes from their grommets.
6. Disconnect the green wire from the top of the
tank.
7. Disconnect the limit thermostat from the side of
the tank.
8. Disconnect the two white wires from the tank
warmer blanket.
9. Disconnect the wires from tank heater terminals.
10. Remove the four #8-32 nuts securing the tank to
the mounting brackets and remove the tank as-
sembly.
11. Remove the eight #8-32 nuts securing the tank lid
to the tank.
12. Remove the two hex nuts securing the tank heater
to the bottom of the tank. Remove tank heater with
gaskets and discard.
13. Install new tank heater(s) with gaskets to the bot-
tom of the tank and secure with two hex nuts.
14. Install tank assembly onto mounting brackets and
secure in place with four #8-32 nuts.
15. Install tank lid and secure in place with eight #8-32
nuts.
16. Connect the two white wires of the tank warmer
blanket.
1425W
Small
Dia.
39132 041708