Water Level Control Operation - Curtis RU-150 Service Manual

WATER LEVEL CONTROL OPERATION

For the contact points referenced in this section,
see the schematic diagram below.
Components Involved:
1. Probe Assembly
2. Liquid Level Control Board
3. Water Inlet Valve Assembly
PROBLEM: Water is not flowing into the urn
jacket.
PROCEDURE:
Turn off the unit and test the probe assembly
and check for grounded wiring. Pull orange wire
from the terminal of the liquid level control board
at point A, with the quick disconnect terminal
attached to the orange wire and with the other
lead of the meter, touch the metal surface of the
urn. Any reading in the meter dial will indicate
the presence of a ground in either the terminals,
wire, or probe assembly. Find the ground and
repair it. If there is no reading at all on your ohm-
meter, the probe is okay. Return the orange wire
to the terminal 4 of the liquid level control board
where it was removed.
Turn the unit on and clamp the leads of your volt-
meter at the terminals of the valve coil as shown
at B of the illustration below. Under normal
conditions, the voltmeter should read 110 to 120
volts while the urn is filling up and power to the
coil should stop once the water level reaches the
probe tip. If the voltmeter does not show voltage,
the liquid level control board is not working prop-
erly. It is not sending power to the solenoid valve
and the valve does not open. Replace the board.
If both the probe and the liquid level control
board are functioning normally, check the water
inlet valve. Turn on the unit and disconnect the
white and the blue wires from the coil on the
valve (points B). Use a lamp cord with alligator
clips; hookup the terminals to the cord. Plug the
cord into a 120 volt outlet. The valve should open
when plugged in and close when unplugged.
Repeat this three or four times. If you don't hear
the sound of the solenoid, then the coil is bad. If
you hear water flowing through the valve when
unplugged, the diaphragm is either torn or needs
cleaning. Replace the water inlet valve.
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