Tank Heater; Disconnect The Brewer From The Power Source - Bunn Single Operating & Service Manual

SERVICE (cont.)

TANK HEATER

FIG. 26 TANK HEATER
Location:
The tank heater is located inside the hood on the
right rear of the tank lid.
Test Procedure:
Electro/Mechanical Models.
1. Disconnect the brewer from the power supply.
2 Check the voltage across the black and the red wire
on 120V, 208 or 240V models on the tank heaters.
With a voltmeter, and with the control thermostat
turned to the "ON" position (fully clockwise), con-
nect the brewer to the power supply and check
the voltage across the wires. The indication should
be:
a.) 120 volts ac for two wire 120 volt models,208
volts ac for three wire 120/208 volt models and
240 volts ac for three wire 120/240 volt models.
b.) 200 to 240 volts ac for two wire 200 or 240
volt models.
3. Disconnect the brewer from the power supply.
BLK to Contac-
tor T2
P824
RED to Con-
tactor T1
ELECTRO/MECHANICAL
FIG. 27 TANK HEATER TERMINALS
If voltage is present as described, proceed to #4. If
voltage is not present as described, refer to the wiring
diagrams and check the wiring harness.
4. Disconnect wires from the tank heater and check
for continuity across the terminals of the tank
heater.
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 the heater for cracks in the sheath.
Electronic Control Models:

1. Disconnect the brewer from the power source.

2. Disconnect wires from heater.
3. Check for continuity across the tank heater termi-
nals.
If continuity is present as described, 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 the heater for cracks in the sheath.
Removal and Replacement:
1. Remove wires from tank heater.
2. Remove the four #8-32 nuts securing tank heat to
tank lid.
3. Remove tank heater and gasket.
4. Install new tank heater and gasket with four #8-32
nuts on tank lid.
5. Refer to Fig. 27 when reconnecting the wires.
BLK to Limit
Thermostat
Page 35
BLU Lead from Triac
Assy.
ELECTRONIC
P837
27038 030901