Bunn ES.1A - Manual (Page 17)

15
BUNN Espress™ Model ES•1A™ TROUBLESHOOTING
Probable cause
Solenoid valve
Pump
Solenoid valve
Limit thermostat(s)
Tank heater
Remedy
Check voltage at terminals. If voltage is
present when the dose switch is pressed,
disconnect power supply, remove wires
from coil terminals and check coil termi-
nal continuity. If there is continuity re-
place solenoid.
When start switch is pressed, pump should
turn on immediately. If this dies not hap-
pen, check voltage at terminal block on the
pump. If correct voltage is present, use a
flat-blade screwdriver to turn the motor
shaft on the rear end of the motor to see if
the pump itself is locked up. If the shaft
does not turn, replace pump assembly.
Remove the solenoid valve and clear it of
any obstructions. Rebuild or replace the
valve if necessary.
Disconnect power supply , remove all wires
check across limit terminals for continuity.
If no continuity, replace limit thermostat(s).
Check tank heater terminals for correct
voltage. If voltage is present and machine
is not heating properly, replace tank heater.
Problem
Brew cycle will not
start (cont.)
Water is not hot or
long recovery time.