16
TROUBLESHOOTING
To help the service technicians in the eld to
understand the operation of the RU models, we
separate the basic functions of the unit into four
different areas:
1. Heat Supply
2. Water Level Control
3. Brewing Cycle
4. Aeration
These four functions, even though they utilize
the same power supply, work independently from
each other.
In the following illustrations, problems are isolated
to only that system where a malfunction is locat-
ed, so in the eld or shop, you will know exactly
what components are involved.
HEAT SUPPLY OPERATION
For the contact points referenced in this section,
see the schematic diagram below.
Components involved:
1. Power Block
2. Thermostat
3. Heating Elements
HEAT SUPPLY
PROBLEM: Water will not heat up or heats up
too slowly.
PROCEDURE: Take a voltage reading at termi-
nals L1 and L3 of the power block (marked A & A)
and if there is current at the power block.
If there is power, turn the thermostat all the way
to boil and clamp your ammeter around heating
element wire at point B shown in the single phase
diagram below. The reading should be approxi-
mately the same as indicated in the serial plate of
the machine.
If the meter reads only half of the amps that
your urn is rated at (check serial plate), one of
the heating elements has burnt out. Clamp your
ammeter at points C to determine which of the
heating elements is bad. Replace the heating ele-
ment.
If the water temperature in the urn is too hot (boil-
ing) or too cold when the pilot light goes out, the
thermostat must be calibrated. Reset the thermo-
stat calibration, refer to the steps on page 10.
If the thermostat will not hold a calibration, re-
place the thermostat.
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