Grindmaster AMERICAN METAL WARE 87710 - Manual (Page 10)

American Metal Ware 87710E Coffee Urn Page 11
Possible Cause
1. No power at urn.
2. Power at urn, but no power
at heater terminals.
3. Power at heater terminals,
but no heat.
Possible Cause
1. Thermostat out of calibration.
2. Thermostat is inoperative.
Fluid has leaked out of
diastat assembly of thermostat.
3. Contractor sticking in
closed position.
Service Checks and Cures
Check main switch. Check main fuses.
(Three on 3 phase power, two on single
phase power). Check that pilot light at top
of thermostat bezel is ON.
Check urn control circuit breaker or fuse,
reset or replace if needed. Check that water
level is at STOP mark on gauge. Check that
power contractor has power at coil, and
clicks open and closed at thermostat dial is
turned off and to BREW position. Check
control transformer, if supplied. It may be
burned out. Lastly, check for voltage at
heater terminals. If voltage at heater is
O.K., check for broken or loose wire. Water
must be showing in center gauge glass 2” if
Opt. 39 equipped.
Check heater for an open circuit with
ohmmeter or continuity tester. If necessary,
replace heater. (It is necessary to remove
coffee liner to replace electric heater).
Service Checks and Cures
Set knob on “BREW” and remove knob by
pulling outward. Using small screwdriver in
center of shaft, turn slotted screw clockwise
until pilot light goes out. Check holding
temperature by adding cold water. Light
should come on and water heat up to high
end of “BREW” zone on thermometer dial
and then shut off. NO BOILING.
If impossible to get control to cycle on and
off and control temperature, replace entire
control. Be sure to drain water in urn below
level at which bulb enters urn. Also, shut off
all power before service is attempted.
Contactor must click on and off. If it sticks,
replace.
Operation Malfunction and Service
Problem - Thermostat dial turned to brew and water in tank remains cold.
PROBLEM: Water boils continuously with thermostat dial on position
“BREW” or “HOLD.”