Bunn FMD-1 User Guide

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b) 208 volts ac for three wire 120/208 volt models.

 

c) 240 volts ac for three wire 120/240 volt models.

 

d) 230 volts ac for two wire 230 volt models.

5.  Disconnect the dispenser from the power source.

If voltage is present as described the control thermostat 

is operating properly. Reinstall bulb into the tank.

If voltage is not present as described, replace the ther-

mostat.

Removal and Replacement.

1.  Remove  the  thermostat  capillary  bulb  by  firmly 

pulling-up on the capillary at the tank lid. This will 

disengage the grommet from the tank lid.

2.  Loosen the two #6-32 screws securing the thermostat 

to the front tank mounting bracket.

3.  Disconnect the wires from the thermostat.

4.   Remove  thermostat  and  remove  the  screws  and 

spacers from the thermostat.

5.  Discard thermostat.

6.  Install two spacers and two #6-32 screws on the 

new thermostat. 

7.  Position the thermostat on the botttom side of the 

front  tank  mounting  bracket  and  tighten  the  two 

#6-32 screws. 

8.  Slide the grommet to the line 4.5” above the bulb on 

the new capillary tube.

9.  Insert the capillary bulb through the hole in the tank 

lid and press the grommet firmly and evenly so that 

the groove in the grommet fits into the tank lid.

10. Carefully bend the capillary tube so that the tube and 

bulb inside the tank are in the vertical position and 

away from any electrical connections.

11. Refer to Fig. 11 and reconnect the wires. 

NOTE - The capillary tube must be clear of any electrical 

termination and not kinked.

FIG. 11 THERMOSTAT TERMINALS

P1668

BLK from Limit

Thermostat

BLK from Tank

Heater Switch

FIG. 12 CONTROL BOARD

Location:

          The Control Board is located behind the lower front 

access cover mounted on the component bracket.

Test Procedure:

Liquid Level Control Circuitry:

1.  Disconnect the dispenser from the power source.

2.   Disconnect the six pin connector from J3 of the 

control board.

3.  Check the voltage across pins 5 & 6 of  the six pin 

connector on the wiring harness with a voltmeter. 

Connect the dispenser to the power source. The 

indication must be 24 volts ac.

4.  Disconnect the dispenser from the power source.

If voltage is present as described, proceed to step 5.

If voltage is not present as described, refer to the wiring 

diagram and check the dispenser wiring harness.

5.  Reconnect the six pin connector of the wiring har-

ness to J3 of the control board.

P1666

29112 091307