Tank Heater - Bunn FMD-3 Operating & Service Manual

SERVICE (cont.)

TANk HEATER

FIG. 35 TANK HEATER
Location:
The tank heater is located inside the tank and se-
cured to the tank lid.
Test Procedure:
1. Disconnect the dispenser from the power source.
2. With a voltmeter, check the voltage across the
black and white wires 120 volt or 240 volt models
or black and red wires for 120/208 volt models or
120/240 volt models. Connect the dispenser to the
power source. The indication must be:
a) 120 volts ac for two wire 120 volt models;
b) 208 volts ac for three wire 120/208 volt mod-
els.
c) 240 volts ac for three wire 120/240 volt models
and two wire 240 volt models.
d) 230 volts ac for two wire 230 volt models.
3. Disconnect the dispenser from the power source.
If voltage is present as described, proceed to #4.
If voltage is not present as described, refer to the
dispenser Wiring Diagrams and check the wiring har-
ness.
4. Disconnect the black wire and the white 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.
NOTE - If the tank heater remains unable to heat, remove
and inspect heater for cracks in the sheath.
Removal and Replacement:
1. Shut off water supply to the dispenser.
2. Disconnect the water supply tube on the tank lid.
3. Disconnect the black wires on the limit thermo-
stat.
4. Disconnect the black wire and the white or red wire
from the tank heater terminals.
5. Disconnect the pink wire from the liquid level
probe.
6. Disconnect the green wire from the tank.
7. Remove the thermostat capillary bulb/temperature
P1637.40
probe by firmly pulling up on the capillary at the
tank lid. This will disengage the grommet from the
tank lid.
8. Remove the ten #8-32 nuts securing the tank lid to
the tank.
9. Remove tank lid with limit thermostat, liquid level
probe and tank heater as an assembly.
10. Remove the two hex nuts securing the tank heater
to the tank lid. Remove tank heater with gaskets
and discard.
11. Install new tank heater with gaskets on the tank lid
and secure with two hex nuts.
12. Install tank lid with limit thermostat, liquid level
probe and tank heater on the tank and secure with
ten #8-32 hex nuts.
13. Connect water inlet line to the tank lid.
14. Reconnect the black wires to limit thermostat, the
pink wire to the liquid level probe and the green
wire to the tank. Refer to the limit thermostat and
the liquid level board and probe sections in this
manual when reconnecting wires.
15. Refer to Fig. 36 when reconnecting the wires to
the tank heater.
37
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