CU50
Service Manual
Introduction:
This ice machine is the result of Scotsman’s This manual includes the information needed to
decades of experience as an industry leader in the install, start up, maintain and service the ice
design and manufacture of both commercial and
residential ice machines.
machine. Note any Caution or Warning indicators,
as they provide notice of potential hazards. Keep
this manual for future reference.
Table of Contents
Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Page 2
Cabinet Layout . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Page 3
Air flow . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Page 4
Water Quality . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Page 5
Door Covering . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Page 6
Door Panel Attachment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Page 7
Custom Panel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Page 8
Door swing change . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Page 9
Installation: Water & Drain . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Page 10
Gravity Drain . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Page 11
Electrical . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Page 12
Cube Size Adjustment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Page 13
Harvest Time Adjustment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Page 14
Control Settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Page 15
Use . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Page 16
How to clean the condenser and winterize. . . . . . . . . . . . . . . . . . . . . . . . . . . . Page 17
How to remove scale from the ice making system. . . . . . . . . . . . . . . . . . . . . . . . Page 18
System Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Page 19
Water System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Page 20
Components . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Page 21
Controller . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Page 22
Performance Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Page 23
Refrigeration System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Page 24
Thermistor Values . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Page 25
Service Diagnosis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Page 26
Service Diagnosis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Page 27
Removal and Repair . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Page 28
Removal and Repair . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Page 29
Removal and Repair - Cabinet Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . Page 30
Refrigeration Service . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Page 32
March 2010
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CU50
Service Manual
Cabinet Layout
FLOORRADIN
ACCESS HOLE
98.55
3.88
443.23
17.45
606.68
23.89
566.17
22.29
40.51
1.60
377.95
14.88
753.24
29.66
873.25
34.38
DRAIN
FLEXIBTLUEBING
3/8D.I.PUMP MODLUEDL E(IDN)C
5/8D.I.GRAVTIY MODEOTLI(NNLCUDED)
POTABLWEATER INLET
1/4C"OMPRESSTITOINNGFI
97.79
3.85
82.99
3.27
11V5
POWECRORD
39.75
1.57
AIR OUT
AIR IN
81.28
3.20
LEG
ADJTUMSENT
[25.40]
1.00
97.16
3.83
62.04
2.44
188.98
7.44
March 2010
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CU50
Service Manual
Air flow
The machine takes in room temperature air at the
lower right front and forces warm air out the lower
left front. Restricting the airflow will adversely affect
the ability of the ice machine to make ice.
Control Panel
Ice Making
Area
Warm Air Out
Air Intake
Scotsman Ice Systems are designed and
manufactured with the highest regard for safety
and performance. They meet or exceed the
standards of agencies like U.L.
Scotsman assumes no liability or responsibility of
any kind for products manufactured by Scotsman
that have been altered in any way, including the
use of any parts and/or other components not
specifically approved by Scotsman.
Scotsman reserves the right to make design
changes and/or improvements at any time.
Specifications and designs are subject to change
without notice.
March 2010
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CU50
Service Manual
Water Quality
All water, including potable water supplied by
municipalities, contains some impurities or
Filters and Treatment
minerals. Water absorbs impurities from the air as
rain and/or as it flows through the ground. Some of
the impurities are solid particles, these are known
as suspended solids, and a fine particle filter will
remove them. Other impurities are chemically
bonded to the water molecules, and cannot be
filtered out, these are called dissolved solids.
In general, it is always a good idea to filter the
water. A water filter, if it is of the proper type, can
remove taste and odors as well as particles. Some
methods of water treatment for dissolved solids
include reverse osmosis, and polyphosphate
feeders.
RO Water
Ice made by this machine will have a lower mineral
content than the water it was made from. This is
due to the method of making ice. Purer water will
freeze first in the ice making molds. The reason for
this is that anything dissolved in water lowers the
water’s freezing temperature. This concentrates
most of the impurities in the ice machine water
reservoir where they may form hard deposits
known as scale. The machine dilutes the
This machine can be supplied with Reverse
Osmosis water, but the water conductivity must be
no less than 10 microSiemens/cm. A reverse
osmosis system should include post treatment to
satisfy the R.O. water’s potential aggressiveness.
Deionized water is not recommended and is too
clean to allow the machine to function.
concentration of minerals by over-filling the
reservoir during the harvest cycle (with the excess
water flowing down the drain). Between 2 and 4
pints of water flow into the unit each cycle.
Between 1 and 3.5 pints of that rinses the reservoir
and goes down the drain.
Because water softeners exchange one mineral for
another, softened water may not improve water
conditions when used with ice machines. Where
water is very hard, softened water could result in
white, mushy cubes that stick together.
If in doubt about the water, contact a local point of
use water specialist for recommendations on water
treatment.
Some impurities will inevitably remain, and will stick
to the parts in the machine, and will cause
malformed ice cubes. Eventually, built up mineral
scale can shorten machine life.
Installation Overview
To keep the machine operating properly, these
impurities or minerals will have to be regularly
dissolved by an acid cleaning, using Scotsman Ice
Machine Scale Remover. Directions for this may be
found in the section under cleaning.
The ice machine must:
• be connected to cold, potable water
• be connected to a drain
• be connected to the proper power supply
• be able circulate air through the vents at the
front.
Note: Do not build in so that the door is recessed.
March 2010
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CU50
Service Manual
Door swing change
The door can be attached to open with hinges on
the left or right. Retain all screws for re-use.
6. Remove original bottom hinge.
To change:
1. Remove top hinge pin from hinge.
7. Remove two plugs or screws from upper
cabinet bracket.
8. Attach bottom hinge to upper cabinet bracket
using the original screws.
9. Place the door on bottom hinge, tip up to slide
under top hinge.
2. Tilt top of door away from cabinet and lift door
off bottom hinge.
10. Insert hinge pin into top hinge and door.
11. Tighten hinge pin.
12. Replace screws or plugs into holes left by
hinges.
13. Check action and swing of door.
3. Remove two screws and top hinge.
4. Remove plugs or screws from lower cabinet
bracket
5. Attach top hinge to lower cabinet bracket using
original screws.
March 2010
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CU50
Service Manual
Installation Notes
Sealing to floor: In some cases the base of the ice
machine must be sealed to the floor to meet local
code. Food grade silastic sealant such as
Scotsman part number 19-0529-01 is
recommended.
Place the machine in the intended location. Turn
the leg levelers in until the bottom of the unit is as
close to the floor as possible. Be sure the unit is
level and all four levelers are in contact with the
floor.
Place a bead of the sealant between the floor and
the outside edge of the cabinet. The bead must fill
the space between the cabinet bottom edges and
the floor.
Built In Situations: If a finished floor is to be
installed in the area after the ice machine has been
built in, shims the expected thickness of the floor
should be installed under the unit to keep the
machine level with the planned floor level.
Installations on a slab: Use a pump model and
pump the water to the point of drainage. Pump
models will pump 1 story (10 feet) high.
Installations over a crawl space or basement:
Either gravity drain or pump model units may be
used, if there is not enough room behind the
machine for a drain/waste receptacle, the drain will
have to be below the floor.
Note: When installed in a corner, the door swing
may be limited due to handle contact with the wall
or cabinet face.
March 2010
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CU50
Service Manual
Installation: Water & Drain
The recommended water supply tubing is ¼ inch
OD copper. Stainless steel flex or reinforced PVC
Drains
tube may also be used. Install an easily accessible There are two types of ice machine models, one
shut-off valve between the supply and the unit. This that drains by gravity and one that has an internal
shut-off valve should not be installed behind the
unit.
drain pump.
Drain Pump Model drain installation
Note: Do not use self-piercing type valves.
1. Remove the front service panel.
1. Locate the coil of 3/8” ID plastic drain tubing
secured to the back of the unit.
2. Route the plastic drain tube from the back of the
unit to the drain connection point.
IMPORTANT NOTE: Often an air gap is required by
local codes between the ice maker drain tube and
the drain receptacle.
Screw
Securing
Front Service
Panel
2. Route the tubing through the right hole in the
back to the inlet water solenoid valve inlet.
3. Install a compression fitting on the tubing and
connect to the inlet of the solenoid.
Water Inlet
Tube (field
supplied)
Drain Tube,
Route to
building drain
Back View, Drain Pump Model
March 2010
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CU50
Service Manual
Gravity Drain
Caution: Restrictions in the drain system to the
machine will cause water to back up into the ice
storage bin and melt the ice. Gravity drain tubing
must be vented, have no kinks and slope to the
building drain. Air gaps are typically required by
local code.
4. Connect a straight 5/8” barbed connector to the
drain hose, securing with the clamp removed in
step 4.
5. Cut an 8” piece of 5/8” ID X 7/8” OD tygon (clear
plastic) tubing. Slide one end of the tube onto the
outlet of the barbed connector and secure with a
clamp. Leave the other end of the tube lying on the
floor of the base pan until the unit is positioned
over the floor drain.
1. Place the ice machine in front of the installation
opening. Adjust leveling legs to the approximate
height.
2. Remove the front service access panel and the
upper back panel.
6. Route the drain tube. Either a) Insert the drain
tube through the base pan into the floor drain or b)
Route the drain tube through the left hole in the
lower back panel and connect to barbed elbow and
secure with a clamp.
Note: If you are connecting a gravity drain model
and the drain opening has been located in the floor
under the base pan according to the pre install
specifications, follow steps 3 through 5 to drain the
unit through the base. If not, proceed to step 6b.
7. Reinstall the upper back panel.
8. Reinstall the service access panel. Level the
unit.
3. Remove the clamp and barbed elbow and take
off the plastic cover in the base pan below the drain
hose.
Barbed Elbow
Drain Hose
Water Inlet
Tube (field
supplied)
Drain Hose,
Route to
building drain
Back View, Gravity Drain Model
March 2010
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CU50
Service Manual
Electrical
The ice machine is supplied with a power cord. Do
not remove the grounding pin from the cord’s plug.
Do not use extension cords. Follow all codes.
Connect the machine to its own 115 volt, 15 amp
circuit.
Installation check list:
1. Has the unit been connected to the proper
water supply?
2. Has the water supply be checked for leaks?
3. Has the unit been connected to a drain?
4. Has the drain been tested for flow and leaks?
1. If the electrical outlet for the ice maker is
behind the unit, plug in the unit.
2. Position the unit in the installation opening.
5. Has the unit been connected to the proper
electrical supply?
3. Turn on the water supply. Make sure that the
ice maker is plugged in and the power is on.
6. Has the unit been leveled?
4. Slide unit into installation opening, paying
careful attention to water supply and drain
connections. Do not kink!
7. Have all packing materials been removed from
the machine?
5. Pour a couple of quarts of water into the ice
storage bin; on drain pump equipped machines
the drain pump should start and water should
pump out. Check for leaks.
8. Has the door covering been installed?
Initial Start Up
1. Turn on the water supply.
6. Replace the service access panel.
7. Level the unit as needed.
2. Switch on the electrical power.
3. Push and release the On/Off switch to start the
machine. The Ice Making light next to the
On/Off switch will glow Green.
Water will begin to flow into the unit. When the
reservoir is full, water will start to drain from the
machine. After a few minutes the compressor,
water pump and fan motor will begin to operate
and the first ice making cycle will have begun.
4.
No adjustments are needed.
After about a half hour, ice will fall into the ice
storage bin. The machine makes 24 cubes per
batch. It is normal for the first batches of ice to
melt, that continues until the bin has cooled. It will
take 8 to 10 hours of continuous run time to fill the
ice bin. When the bin is full of ice, the ice machine
will shut off. It will automatically restart when the
ice level falls, either from use or normal meltage.
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CU50
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Cube Size Adjustment
The cube size can be adjusted by changing the
amount of freeze cycle time. This is done by a
button press sequence.
Side Views of Cubes
Note: There is only one correct cube size. See the
illustrations.
To adjust cube size:
1. Shut the machine off: If it's off on bin full press
and release the On/Off button once, switching the
Ice Making light off. If the machine is making ice
hold the On/Off button in until the Ice Making light
is off.
Too Small, Adjust Cycle Longer
2. Press and hold the Clean button for 5 seconds
(light on), then release (light out)
3. View the lights. Compare to the table below.
Cube Size Change Table
Just Right
On/Off
off
Water
off
Clean
off
Default
Add 1 minute
on
off
off
Add 2 minutes off
Add 3 minutes off
Add 4 minutes on
on
off
off
on
on
on
- 1 minute
- 2 minutes
- 3 minutes
- 4 minutes
flash
off
off
off
flash
off
off
off
flash
flash
Too Large, Adjust Cycle Shorter
flash
flash
4. Select the amount of change.
5. Push and release the On/Off button until the
correct light pattern is displayed.
6. Push and release the Clean button to select that
setting.
7. Push and release On/Off to return to ice making.
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CU50
Service Manual
Harvest Time Adjustment
The harvest time can be adjusted so that all the ice
harvests during the cycle, plus a few seconds
extra. This is done by a button press sequence.
Harvest Time Table
On/Off
off
Water
off
Clean
off
Default
Note: Do not set harvest time shorter than the
actual time it takes to release all the cubes.
Add 10 seconds on
Add 20 seconds off
Add 30 seconds off
Add 40 seconds on
off
off
on
off
To adjust Harvest Time:
off
on
1. Shut the machine off by holding the On/Off
button in until it shuts off (Ice Making light off).
on
on
- 10 seconds
- 20 seconds
- 30 seconds
- 40 seconds
flash
off
off
off
flash
off
off
2. Press and hold the On button again for 5
seconds, then release (Ice Making light will switch
off).
off
flash
flash
flash
flash
3. View the lights. Compare to the table below.
4. Select the amount of change.
5. Push and release the Clean button until the
correct light pattern is displayed.
6. Push and release the On button to select that
setting.
7. Push and release On/Off to return to ice making.
Ice Making
Indicator Light
Check Water
Indicator Light
Clean - Reset
Button
On - Off
Button
Time To
Clean Unit
Indicator Light
Control Panel
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CU50
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Control Settings
Automatic water purge enable / disable
The control is set at the factory to automatically
select the proper amount of water purge. If desired,
that can be disabled, and a typical purge amount
used.
To disable Automatic purge selection:
1. Press and hold the On/Off button until the unit
shuts off. No lights should be on.
2. Press and hold the ON button for 5 seconds,
then release.
3. Wait between 5 and 20 seconds, then repeat
step 1. All lights will flash once.
To return to Automatic purge selection:
1. Press and hold the ON button for 5 seconds,
then release.
2. Wait between 5 and 20 seconds, then repeat
step 1. All lights will flash twice.
Manual Harvest - from the OFF or Standby Mode
(powered but no lights are on)
1. Press and hold the Clean-Reset button for 5
seconds and release.
2. Wait between 5 and 20 seconds, then repeat
step 1. All lights will flash once. The On/Off light will
be on until harvest has timed out.
Reset time to clean indicator light
Press and hold the Clean-Reset button for 3
seconds.
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CU50
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Use
No special instructions are needed for use. Just
take as much ice as you need, the machine will
replace it. A scoop is provided, and it can be stored
in the machine using the loop of tubing on the right
side as a holder.
The machine can be shut off anytime by just
pushing and releasing the On/Off button. The
machine will shut off at the end of the next cycle.
To shut off immediately, push and hold the On/Off
button in until the machine stops.
Normal cubes are tapered cylinders. If the cubes
are ragged and mis-shaped, mineral scale must be
removed from the ice making system
What shouldn’t be done?
Never keep anything in the ice storage bin that is
not ice. Objects like wine or beer bottles are not
only unsanitary, but the labels can slip off and plug
up the drain.
Maintenance
There are 5 things to keep clean:
1. The outside cabinet & door.
2. The ice storage bin.
3. The condenser.
Never allow the machine to operate without regular
cleaning. The machine will last longer if it is kept
clean. Regular cleaning should happen at least
once per year, and preferably twice. Some water
conditions will dictate even more frequent cleaning
of the ice making section, and some carpets or
pets will dictate more frequent cleaning of the
condenser.
4. The ice making system.
5. The ice scoop.
Note: The Time to Clean light will switch ON after 6
months of use. It will remain ON until the ice
making system is cleaned using the process on
page 13.
How to clean the cabinet.
Wipe off any spills on the surface of the door and
handle as they occur. If anything spilled on the
door or gasket dries onto the surface, wash with
soap and warm water to remove.
Noise:
The ice machine is designed for quiet operation,
but will make some noise during the ice making
cycle. During a freezing cycle, it is normal to hear
the fan moving air and the water pump circulating
water. Ice hitting the bin or ice in the bin can be
heard during harvest.
How to clean the ice storage bin.
The ice storage bin should be sanitized
occasionally. It is usually convenient to sanitize the
bin after the ice making system has been cleaned,
and the storage bin is empty.
A sanitizing solution can be made of 1 ounce of
household bleach and two gallons of hot (95oF. –
115oF.) water. Use a clean cloth and wipe the
interior of the ice storage bin with the sanitizing
solution, pour some of the solution down the drain.
Allow to air dry.
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CU50
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How to clean the condenser and winterize.
Condenser cleaning
Winterizing
The condenser is like the radiator on a car, it has
fins and tubes that can become clogged with dirt
and lint. To clean:
1. Clean the ice making system.
2. Open the door and push and release the On/Off
switch to turn the machine off.
1. Remove the kickplate and front service panel.
2. Locate the condenser surface.
3. Turn off the water supply.
4. Drain the water reservoir by removing the rubber
cap under the reservoir - it's near the back wall of
the ice storage bin.
Rubber Cap
5. Disconnect the incoming water line at the inlet
water valve.
3. Vacuum the surface, removing all dust and lint.
Caution: Do not dent the fins.
6. Open the door, push and release the on/off
switch to turn the machine on.
7. Blow air through the inlet water valve; a tire
pump could do the job.
4. Return the kickplate and front service panel to
their original positions. Fasten them to the cabinet
using the original screws.
8. Drain pump models should have about 1/2
gallon of RV antifreeze (propylene glycol) poured
into the ice storage bin drain.
Note: Automotive antifreeze must NOT be used.
9. Switch off and unplug the machine.
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CU50
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How to remove scale from the ice making system.
1. Scoop out all of the ice, either discard it or save 9. Pour a gallon of hot (95oF. – 115oF.) water into
it in an ice chest or cooler.
the bin to flush out the drain.
2. Press and HOLD the On/off button in for 3
seconds until the Green light goes out.
10. Clean the bin liner of mineral scale by mixing
some ice machine scale remover and hot water,
and using that solution to scrub the scale off of the
liner.
11. Rinse the liner with hot water.
12. Sanitize the bin interior.
3. Press and HOLD the both the Clean-Reset and
On/Off buttons for 5 seconds. The Time to Clean
light will blink on and off.
13. Replace the ice removed in step 1.
14. Push and release the On/Off button to restart
ice making.
4. Pour 8 ounces of Scotsman Ice Machine Scale
Remover (available from a local Scotsman
Distributor or Dealer) into the ice machine
reservoir.
The ice scoop should be washed regularly, wash it
just like any other food container.
Pour Scale
Remover Here
5. Operate the machine for about ½ hour.
6. Push and release the On/Off switch. The
machine will begin to flush out the cleaning
solution.
7. Operate the machine for another ½ hour.
8. Push and release the On/Off switch. The
machine will stop the cleaning process.
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CU50
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System Information
Overall:
Electrical Sequence:
A closed bin thermostat signals to the controller a
need for ice. The controller checks for water, if
water is needed , the controller opens the inlet
water solenoid valve to fill the reservoir. The hot
gas valve is open to equalize the system. When the
reservoir is full, the compressor, fan motor, water
pump are switched on. After 5 seconds the hot gas
valve shuts and ice making begins.
• Refrigerant: 8 oz R-134a
• Compressor: Hermetic, 1300 BTUH,
• Condenser: Forced draft
• Fan blade: 5 blade, 7 inch
• Evaporator: Inverted, 24 cube cells. Copper
cups attached to continuous serpentine
• Metering device: Cap tube
• Defrost method: Hot gas bypass with water
assist
Water is sprayed up into the inverted cup mold. As
the water is cooled and ice begins to form in the
cups, the temperature of the evaporator will fall.
• Spray method: 6 water jets
• Water charge: 40 ounces
• Water valve: 115 volt solenoid, .19 GPM
The freeze cycle continues until the temperature of
the thermistor attached to the evaporator outlet
tube falls to about zero degrees F. At that point the
controller starts a freeze cycle timer, whose default
time is 10 minutes. At the end of the freeze cycle's
timed portion the controller switches to the harvest
cycle.
• Water fill time: Varies with harvest time &
purge setting
• Spray pump: Pedestal type.
• Drain pump: Magnetic drive, controlled by
pressure switch
• Purge method: Overflow standpipe
• Control method: Electronic
The harvest cycle begins with the controller
stopping the water pump and fan motor. At the
same time it opens the hot gas valve and the inlet
water solenoid valve. The ice is released by the
combination of discharge refrigerant gas entering
the evaporator serpentine and warming up the
copper, plus the inlet water that flows to the
evaporator, floods across the plastic platen to
warm it up and be pre-chilled for the next cycle. Ice
cubes drop individually and harvest continues until
the thermistor attached to the suction line warms
up to about 50 degrees F. At that point a harvest
timer starts, whose default time is 20 seconds. At
the end of that time the harvest cycle ends and the
freeze cycle restarts.
• Cycle control: Thermistor + timers
• Freeze cycle timer: 10 minutes, + - 4
• Harvest cycle timer: 20 seconds, + - 40
• Cube size adjustment: Freeze timer change.
• Harvest cycle adjustment: Harvest timer
change
• Bin control: Thermostat. Opens on
temperature fall, Cut Out: 35 degrees F. Cut
In 45 degrees F. Range is adjustable.
Electrical Components:
• Compressor
• Fan motor
• Spray pump motor
• Drain pump motor
• Drain pump switch
• Inlet water solenoid valve
• Hot gas valve
• Transformer
Bin control.
The machine's on and off modes are regulated by a
bin thermostat. The cap tube for the bin thermostat
is in the tube that holds the scoop. The machine
will only begin ice making when the thermostat's
contacts close. If the contacts re-open before the
temperature of the evaporator drops below a preset
point, the machine will stop. If the temperature is
below that point when the contact s open, the
machine will continue through a complete cycle
and stop at the end of the harvest cycle.
• Controller
• Water sensor
• Thermistor
• Bin thermostat
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Water System
The controller uses a Water Sensor to check for
the presence of water in the reservoir and to
measure the conductivity of the water.
Evaporator
The water sensor consists of two stainless steel
probes located in a holder next to the water pump.
The probes sense the conductivity of the water.
The higher the mineral content of the water, the
better it can conduct electricity. The control system
is capable of sensing water as clean as 10
microSiemens/cm.
Pump
If the controller cannot sense water and the bin
thermostat is closed the controller will power the
inlet water solenoid valve to fill the reservoir. The
water fill is timed. There is a maximum amount of
time allowed from the time the controller turned on
the inlet water valve until the water sensor signals
to the controller. That time is 2 1/2 minutes. If
water is not sensed within 2 1/2 minutes, the
controller will not proceed with an ice making
cycle. Instead it will blink the Water light and try
filling the reservoir in 20 minutes.
Reservoir
Drain
Freeze Cycle Water Schematic
Reservoir water dilution
The process of making ice from circulating water
causes the pure water to freeze first, because it
freezes at the warmest temperature. The remaining
water will develop an increasing concentration of
minerals. If that mineral concentration were
allowed to continue, eventually the ice machine
would become coated with mineral scale.
To combat the mineral build up, the reservoir water
is diluted with fresh water every cycle. The
controller adds enough water to fill the reservoir
and extra water to overfill it. The extra water drains
out through the standpipe in the reservoir.
Standpipe
The controller keeps the inlet water solenoid valve
open until the evaporator temperature set point is
reached, plus some extra time. The extra time is
either pre-set or automatically determined by the
controller.
Inlet Water Solenoid Valve
Harvest Cycle Water Schematic
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Components
Model and
Serial Tag
Location
Scoop and Thermostat Bracket
Control Panel, Bin Light and Curtain
Evaporator Platen
Evaporator and Controller
Inlet Water Solenoid Valve
Condenser and Bin Thermostat
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Controller
High
Voltage
Connector
Evaporator
Thermistor
Bin
Thermostat
Comp
Water Sensor
Water
Hot Gas
Fan
Power
Power Supply
Connector
Control Panel
Ribbon
The controller is located at the front of the unit,
under the top panel.
Control Safeties:
No Water. If the Water Sensor cannot detect
water, and the inlet water solenoid valve has been
on for the maximum fill time, the controller will stop
all action and wait 20 minutes to re-try water fill.
During this time the Check Water light on the
control panel will be blinking,
It is powered by a 12 volt transformer. It has 5
indicator lights:
• Compressor - Light is ON if compressor is
powered
• Water - Light is ON if inlet water solenoid
valve is powered
Maximum Freeze Time. If the freeze cycle should
extend to 60 minutes, the controller will
automatically put the machine into a Harvest cycle.
• Hot Gas - Light is ON when Hot Gas Valve is
powered
• Fan - Light is ON when Fan motor is
powered
Maximum Harvest Time. 6 minutes
• Power - Light is ON when power is
connected to controller
Time between restarts. After the machine has
operated and then turned off, the controller will not
restart the machine for four minutes.
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Service Manual
Performance Information
Air Temperature
70
Freeze Cycle, Minutes
100
90
80
60
50
100
90
80
70
60
50
40
37-38
36-37
36-35
32-33
27-28
20-21
18-19
36-37
35-36
32-33
28-29
25-26
19-20
17-18
34-35
33-34
30-31
27-28
24-25
18-19
16-17
32-33
31-32
28-29
25-26
22-23
17-18
15-16
31-32
30-31
27-28
23-24
20-21
16-17
15-16
29-30
28-29
26-27
22-23
19-20
15-16
15-16
Water
Temperature
Air Temperature
70
Harvest Cycle, Seconds
80 -100
100
90
80
60
50
55-60
65-75
70-80
100-120
60-70
70-80
75-85
115-125
70-80
80-90
90-100
95-105
140-150
180-200
110-115
115-120
160-170
210-230
70 - 80
Water
Temperature
50 - 70
75-85
85-95
85-95
125-135
150-170
40 - 50
130-140
Air Temperature
70
Total Cycle, Minutes
100
90
80
60
50
100
90
38-39
38-39
37-38
33-34
29-30
21-22
20-21
37-38
36-37
33-34
29-31
27-28
20-21
19-20
36-37
35-36
31-32
28-29
25-26
19-20
19
34-35
33-34
30-31
26-27
24-25
19-20
18-19
33-34
32-33
29-30
25-26
22-23
19
31-32
30-31
27-28
24-25
21-22
18-19
19-21
80
Water
Temperature
70
60
50
40
19
Ice per cycle: 1 lb
Water drained / cycle: Varies by harvest cycle
length and purge setting. Typical amounts are @
70/50 = 52 oz. @ 90/70 = 13 oz
Compressor amps: 2.6 - 3.2
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Service Manual
Thermistor Values
Deg. F · Ohms
Deg. F · Ohms
Deg. F. · Ohms
Deg. F. Ohms
Deg. F. · Ohms
52 · · · 18873
S3 · · · 18381
54 · · · 17903
55 · · · 17439
56 · · · 16988
57 · · · 16551
58 · · · 16126
59 · · · 15714
60 · · · 15313
61 · · · 14924
62 · · · 14546
63 · · · 14179
64 · · · 13823
65 · · · 13476
66 · · · 13139
67 · · · 12812
68 · · · 12494
69 · · · 12185
70 · · · 11884
71 · · · 11592
72 · · · 11308
73 · · · 11031
74 · · · 10763
75 · · · 10502
76 · · · 10247
77 · · · 10000
78 · · · 9760
79 · · · 9526
80 · · · 9299
81 · · · 9077
82 · · · 8862
83 · · · 8652
84 · · · 8448
85 · · · 8250
86 · · · 8056
87 · · · 7868
88 · · · 7685
89 · · · 7507
90 · · · 7333
91 · · · 7164
92 · · · 6999
93 · · · 6839
94 · · · 6683
95 · · · 6530
96 · · · 6382
97 · · · 6238
98 · · · 6097
99 · · · 5960
100 · · 5826
101 · · 5696
102 · · 5569
103 · · 5446
104 · · 5325
105 · · 5208
106 · · 5093
107 · · 4981
108 · · 4872
109 · · 4766
110 · · 4663
111 · · 4562
112 · · 4463
113 · · 4367
114 · · 4273
115 · · 4182
116 · · 4093
117 · · 4006
118 · · 3921
119 · · 3838
120 · · 3757
121 · · 3678
122 · · 3601
123 · · 3526
124 · · 3452
125 · · 3381
126 · · 3311
127 · · 3243
128 · · 3176
129 · · 3111
130 · · 3047
131 · · 2985
132 · · 2924
133 · · 2865
134 · · 2807
135 · · 2751
136 · · 2696
137 · · 2642
138 · · 2589
139 · · 2537
140 · · 2487
141 · · 2438
142 · · 2390
143 · · 2343
144 · · 2297
145 · · 2252
146 · · 2208
147 · · 2165
148 · · 2123
149 · · 2082
150 · · 2042
151 · · 2003
152 · · 1965
153 · · 1927
154 · · 1890
155 · · 1855
156 · · 1819
157 · · 1785
158 · · 1752
159 · · 1719
160 · · 1687
161 · · 1655
162 · · 1624
163 · · 1594
164 · · 1565
165 · · 1536
166 · · 1508
167 · · 1480
168 · · 1453.
169 · · 1427
170 · · 1401
171 · · 1375
172 · · 1350
173 · · 1326
174 · · 1302
175 · · 1279
176 · · 1256
177 · · 1234
178 · · 1212
179 · · 1190
180 · · 1169
181 · · 1149
182 · · 1129
183 · · 1109
184 · · 1090
185 · · 1071
186 · · 1052
187 · · 1034
188 · · 1016
189 · · 998
190 · · 981
191 · · 965
192 · · 948
193 · · 932
194 · · 916
195 · · 901
196 · · 885
197 · · 871
198 · · 856
199 · · 842
200 · · 828
201 · · 814
202 · · 800
203 · · 787
204 · · 774
205 · · 761
206 · · 749
207 · · 737
208 · · 724
209 · · 713
210 · · 701
211 · · 690
212 · · 679
213 · · 668
214 · · 657
215 · · 646
216 · · 636
217 · · 626
218 · · 616
219 · · 606
220 · · 597
221 · · 587
222 · · 578
223 · · 569
224 · · 560
225 · · 551
226 · · 543
227 · · 534
228 · · 526
229 · · 518
230 · · 510
231 · · 502
232 · · 495
233 · · 487
234 · · 480
235 · · 472
236 · · 465
237 · · 458
238 · · 451
239 · · 444
240 · · 438
241 · · 431
242 · · 425
243 · · 419
244 · · 412
245 · · 406
246 · · 400
247 · · 394
246 · · 389
249 · · 383
250 · · 377
0· · · · 85325
1· · · · 82661
2· · · · 80090
3· · · · 77607
4· · · · 75210
5· · · · 72896
6· · · · 70660
7· · · · 68501
8· · · · 66415
9· · · · 64400
10 · · · 62453
11 · · · 60571
12 · · · 58752
13 · · · 56995
14 · · · 55296
15 · · · 53653
16 · · · 52065
17 · · · 50529
18 · · · 49043
19 · · · 47607
20 · · · 46217
21 · · · 44872
22 · · · 43571
23 · · · 42313
24 · · · 41094
25 · · · 39915
26 · · · 38774
27 · · · 37669
28 · · · 36600
29 · · · 35564
30 · · · 34561
31 · · · 33590
32 · · · 32649
33 · · · 31738
34 · · · 30855
35 · · · 30000
36 · · · 29171
37 · · · 28368
38 · · · 27589
39 · · · 26835
40 · · · 26104
41 · · · 25395
42 · · · 24707
43 · · · 24041
44 · · · 23394
45 · · · 22767
46 · · · 22159
47 · · · 21569
48 · · · 20997
49 · · · 20442
50 · · · 19903
51 · · · 19381
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Service Diagnosis
No Ice
Problem
Likely Cause
Probable Solution
Check breaker or fuse. Reset or
replace, restart and check
No power to unit
Power disconnected
Transformer open
No power to controller
Shut down on maximum
Replace transformer
water fill time - water light Water shut off
flashing
Restore water supply
Water leak
Check curtain, sump
Clean condenser
Dirty condenser
Restricted location, intake air too
hot or blocked
Eliminate restriction, have machine
moved
Evaporator thermistor not sensing
properly
Check thermistor
Remove spray platform and clean
spray jets
Very long freeze cycle
Spray jets dirty
Inlet water valve leaks through
during freeze
Check inlet water valve
Check cube formation,
Low on refrigerant
Check for bleed thru from / missing
check valve in building water
supply
Connected to hot water
Spray pump not pumping
Fan motor not turning
Check pump motor
Check fan motor, check fan blade,
check controller for voltage output
Pump hose disconnected
Check hose
Add access valve, add refrigerant
as a test. If unit makes ice, find and
correct leak.
Very low on refrigerant
Check compressor start
components, check PTCR
resistance and temperature
Cannot make ice
Compressor not operating
Check compressor voltage
Check compressor windings
Hot gas valve leaks through during Check hot gas valve for hot outlet
freeze
during freeze
Check compressor amp draw, if
low and all else is correct, change
compressor
Compressor inefficient
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Service Diagnosis
Makes excessive noise
Problem
Likely Cause
Probable Solution
Replace fan blade
Replace motor mount
Check mounting
Replace pump
Blade is bent
Fan blade vibrates
Fan motor mount is broken
Mounting loose
Compressor vibrates
Water pump vibrates
Panels vibrate
Pump bearings worn
Mounting screws loose
Tighten screws
Makes ice, does not harvest
Problem
Likely Cause
Probable Solution
Ice wrong size
Environment changed
Adjust cube size
Check voltage to coil when unit is
in harvest, check controller
indicator light.
Hot gas valve does not open
Little heat to evaporator
Makes poor quality ice
Water temperature very low
Fan motor does not stop
Adjust harvest time
Check voltage, replace controller
Problem
Likely Cause
Probable Solution
Clean jets
Spray pattern poor
Runs out of water
High TDS water supply
Spray jets dirty
Water leaking from reservoir
Groundwater supply
Correct leak
Treat water
Makes ice, but melts rapidly
Problem
Likely Cause
Probable Solution
Restricted drain
Gravity drain hose has air block
Check for kinks or traps
Pump model switch not starting
pump
Pooled water in bin
Check / replace switch
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Removal and Repair
Bin Thermostat
9. Reverse to reassemble.
Curtain
1. Disconnect electrical power.
1. Shut unit off.
2. Loosen both thumbscrews holding curtain
bracket to freezing chamber.
Electrical Shock
Hazard.
Disconnect electrical
power before
beginning removal
3. Pull out and remove curtain with bracket from ice
machine.
2. Remove service panel.
4. Reverse to reassemble.
Spray Platform
3. Remove back panel.
1. Remove curtain.
Note: If unit is built in it must be pulled out to
change the bin thermostat.
2. Lift spray platform up until it disconnects from its
fitting.
4. Pull cap tube out from the back of the ice
storage bin and cap tube holder.
3. Pull forward and remove from the ice machine.
4. Reverse to reassemble.
Water Pump
5. Remove two screws and the bin thermostat
contact section from its mounting bracket.
6. Disconnect two wires from the bin thermostat
contact section and remove the thermostat from
the ice machine.
1. Remove spray platform
2. Remove back panel.
7. Reverse to reinstall.
Note: If unit is built in it must be pulled out to
change the water pump.
Inlet Water Solenoid Valve
1. Disconnect electrical power.
2. Remove service panel.
3. Shut water supply OFF.
3. Disconnect power and ground wires from pump
motor.
4. Rotate pump body CW and lift up to remove it.
5. Reverse to reassemble.
4. Disconnect inlet water supply tube from inlet
water solenoid valve.
5. Unplug wire harness from valve coil.
6. Remove two screws holding valve to chassis.
7. Squeeze hose clamp larger and push away from
solenoid valve outlet.
8. Pull hose from outlet of valve.
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Removal and Repair
5. Remove screws holding transformer to controller
box and pull transformer up and out of the ice
machine.
Evaporator Thermistor
Note: If unit is built in it must be pulled out to
change the evaporator thermistor.
6. Reverse to reassemble.
Controller
Note: If unit is built in it must be pulled out to
change the controller.
Electrical Shock
Hazard.
Disconnect electrical
power before
beginning removal
1. Disconnect electrical power.
2. Remove top panel
1. Shut machine off. If unit was making ice,
manually harvest the ice.
3. Remove controller box cover.
4. Unplug all connections.
2. Disconnect electrical power.
3. Remove top panel.
5. Remove screws holding controller to housing,
and lift controller from unit.
4. Remove cover from controller box.
5. Disconnect thermistor wire from controller.
Note: To avoid damaging the controller, touch the
metal chassis of the unit prior to touching the
replacement controller.
6. Locate thermistor sensor, it is attached to the
suction line, just above the accumulator and is
covered with insulation tape. Remove the
insulation.
6. Reverse to reassemble.
Control Panel
7. Disconnect sensor bulb from suction line (it's
held on with a metal clip).
1. Disconnect electrical power.
2. Remove top panel
8. Remove thermistor from ice machine.
3. Remove controller box cover.
4. Unplug ribbon cable connection.
9. Reverse to reassemble. It is very important that
the bulb be re-insulated.
Transformer
5. Push control panel away from the front of the
machine. Begin at the ribbon cable attachment
point.
Note: If unit is built in it must be pulled out to
change the transformer.
Note: Control panel is held on by adhesive and the
adhesive is thinnest at the cable point.
1. Disconnect electrical power.
2. Remove top panel.
6. Separate control panel from controller box and
remove from the ice machine.
3. Remove controller cover.
4. Unplug leads from transformer.
7. Reverse to reassemble.
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Removal and Repair - Cabinet Removal
Certain components require the removal of the
cabinet for repair access.
12. Remove curtain & hanger.
1. If the machine is in a freeze mode, perform a
manual harvest.
2. Remove all ice.
3. Drain reservoir.
4. Remove service panel and kick plate.
5. Remove back panel.
13. Locate elbows where water flows onto the
evaporator platen.
6. Disconnect electrical power.
Clip
Electrical Shock
Hazard.
Disconnect electrical
power before
beginning removal
Inlet
Elbow
7. Disconnect water and drain tubing.
8. Remove door.
14. Pull clip up. Push inner elbow back and rotate it
until it points straight up, then push it back through
the hole in the back of the freezing compartment.
9. Remove top panel.
10. Remove controller box cover.
11. Disconnect thermistor from controller, pull wire
back to suction line.
Thermistor
Connector
Inlet
Elbow
Inner
Elbow
15. Pull water inlet elbow out of inner elbow.
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18. Remove two screws holding freezing
compartment brace to cabinet, lift brace up.
23. Lift bin assembly off the base.
Note: Prop evaporator assembly up. A 3' length of
3/4" PVC tubing with one end inserted into the cup
mold and the other against the base will hold it up.
Brace
The hot gas valve, fan motor, condenser and
compressor are now exposed for service.
19. Lift evaporator platen up and tilt back enough
for bin assembly to clear the base.
Air Baffle
20. Remove air baffle.
21. Unplug 7 wire harness connector (at back of
bin).
22. Remove 1 screw at each corner of the base.
Chassis Shown in Front of Bin Assembly
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Refrigeration Service
This ice machine use R-134a type refrigerant.
There are specific rules for handling that
refrigerant.
To check for system pressures, add a field supplied
clamp-on type service valve as a temporary means
of system access. After diagnosis and before final
repair, replace the clamp-on type valve with valves
that are brazed onto the process tubes of the
system.
Use a low flow of dry nitrogen when brazing on the
system.
Install a new filter drier when replacing a
refrigeration component or after a refrigerant leak
repair.
Evacuate the system to at least 300 microns and
use a micron gauge to measure the evacuation
level.
Weigh in the nameplate charge. The machine is
critically charged and a partial ounce mis-charge
will affect performance.
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