Hoshizaki CRMR27 User manual

Models
Undercounter
Worktop
Prep Table
Commercial Series
Refrigerated Kitchen Equipment
Service Manual
Number: 73191
Issued: 9-29-2011
Revised: 5-1-2017
hoshizakiamerica.com

2
WARNING
Only qualied service technicians should install and service the appliance. To
obtain the name and phone number of your local Hoshizaki Certied Service
Representative, visit www.hoshizaki.com. No service should be undertaken until
the technician has thoroughly read this Service Manual. Failure to service and
maintain the appliance in accordance with this manual will adversely affect safety,
performance, component life, and warranty coverage. Proper installation is the
responsibility of the installer. Product failure or property damage due to improper
installation is not covered under warranty.
Hoshizaki provides this manual primarily to assist qualied service technicians in the
service of the appliance.
Should the reader have any questions or concerns which have not been satisfactorily
addressed, please call, send an e-mail message, or write to the Hoshizaki Technical
Support Department for assistance.
Phone: [phone]
Fax: [phone]
E-mail: [email protected]
618 Highway 74 South
Peachtree City, GA 30269
Attn: Hoshizaki Technical Support Department
Web Site: www.hoshizaki.com
NOTE: To expedite assistance, all correspondence/communication MUST include the
following information:
• Model Number
• Serial Number
• Complete and detailed explanation of the problem.

3
IMPORTANT
This manual should be read carefully before the appliance is serviced. Read
the warnings and guidelines contained in this booklet carefully as they provide
essential information for the continued safe use, service, and maintenance of the
appliance. Retain this booklet for any further reference that may be necessary.
CONTENTS
Important Safety Information ................................................................................................. 5
I. Construction and Refrigeration Circuit Diagram ................................................................. 8
A. Construction.................................................................................................................. 8
B. Refrigeration Circuit Diagram........................................................................................ 9
II. Sequence of Operation and Service Diagnosis............................................................... 10
A1. Thermostat Control Sequence of Operation Flow Chart............................................ 10
1. Undercounter and Work Top: Refrigerator.............................................................. 10
2. Prep Table...............................................................................................................11
3. Undercounter and Work Top: Freezer .....................................................................11
A2. Thermistor/Control Module Sequence of Operation Flow Chart ............................... 12
1. Undercounter and Work Top: Refrigerator.............................................................. 12
2. Prep Table.............................................................................................................. 13
3. Undercounter and Work Top: Freezer .................................................................... 14
B1. Thermostat Control Service Diagnosis ...................................................................... 15
1. Undercounter and Worktop: Refrigerator................................................................ 15
2. Prep Table.............................................................................................................. 16
3. Undercounter and Worktop: Freezer...................................................................... 17
B2. Thermistor/Control Module Service Diagnosis.......................................................... 19
C. Defrost Timer Check ................................................................................................... 23
D. Control Module Check................................................................................................. 24
E. Diagnostic Table .......................................................................................................... 26
III. Controls and Adjustments............................................................................................... 28
A. Temperature Settings .................................................................................................. 28
B. Defrost......................................................................................................................... 28
C. Safety Devices ............................................................................................................ 30
D. Perimeter and Mullion Heaters.................................................................................... 30
IV. Refrigeration Circuit and Component Service Information.............................................. 31
A. Refrigeration Circuit Service Information .................................................................... 31
B. Component Service Information.................................................................................. 33
C. Door Reversal ............................................................................................................. 34
D. Door/Drawer Location Reversal .................................................................................. 37
V. Preparing the Appliance for Periods of Non-Use ............................................................. 48
VI. Disposal.......................................................................................................................... 49

4
VII. Technical Information..................................................................................................... 50
A. Electrical and Refrigerant Data ................................................................................... 50
B. Wiring Diagrams.......................................................................................................... 51
1a. Undercounter and Worktop: Refrigerator; Cabinet Thermostat............................ 51
1b. Undercounter and Worktop: Refrigerator; Cabinet Thermistor/Control Module.... 52
2a. Prep Table; Cabinet Thermostat (Without Defrost Heater)................................... 53
2b. Prep Table; Cabinet Thermostat (With Defrost Heater) ........................................ 54
2c. Prep Table; Cabinet Thermistor/Control Module................................................... 55
3a. Undercounter and Work Top: Freezer; Cabinet Thermostat................................. 56
3b. Undercounter and Work Top: Freezer; Cabinet Thermistor/Control Module......... 57

5
Important Safety Information
Throughout this manual, notices appear to bring your attention to situations which could
result in death, serious injury, damage to the appliance, or damage to property.
WARNING Indicates a hazardous situation which could result in death or
serious injury.
NOTICE Indicates a situation which could result in damage to the
appliance or property.
IMPORTANT Indicates important information about the use and care of the
appliance.
WARNING
This appliance should be destined only to the use for which it has been expressly
conceived. Any other use should be considered improper and therefore dangerous.
The manufacturer cannot be held responsible for injury or damage resulting from
improper, incorrect, and unreasonable use. Failure to service and maintain the
appliance in accordance with this manual will adversely affect safety, performance,
component life, and warranty coverage.
To reduce the risk of death, electric shock, serious injury, or re, follow basic
precautions including the following:
• Only qualied service technicians should install and service this appliance.
• This appliance must be installed in accordance with applicable national, state, and
local codes and regulations.
• To reduce the risk of electric shock, do not touch the plug with damp hands.
• Unplug the appliance before servicing.
• This appliance requires an independent power supply of proper capacity. See
the nameplate for electrical specications. Failure to use an independent power
supply of proper capacity can result in a tripped breaker, blown fuse, damage to
existing wiring, or component failure. This could lead to heat generation or re.
• THIS APPLIANCE MUST BE GROUNDED. This appliance is equipped with a
NEMA5-15 three-prong grounding plug to reduce the risk of potential shock
hazards. It must be plugged into a properly grounded, independent 3-prong wall
outlet. If the outlet is a 2-prong outlet, it is your personal responsibility to have
a qualied electrician replace it with a properly grounded, independent 3-prong
wall outlet. Do not remove the ground prong from the power cord and do not use
an adapter plug. Failure to follow these instructions may result in death, electric
shock, or re.
• Do not use an extension cord.
• Do not use an appliance with a damaged power cord. The power cord should not
be altered, jerked, bundled, weighed down, pinched, or tangled. Such actions
could result in electric shock or re. To unplug the appliance, be sure to pull the
plug, not the cord, and do not jerk the cord.

6
WARNING, continued
• The GREEN ground wire in the factory-installed power cord is connected to the
appliance. If it becomes necessary to remove or replace the power cord, be sure
to connect the power cord's ground wire.
• Do not splash, pour, or spray water directly onto or into the appliance. This might
cause short circuit, electric shock, corrosion, or failure.
• Do not make any alterations to the appliance. Alterations could result in electric
shock, injury, re, or damage to the appliance.
• This appliance is not intended for use by persons (including children) with reduced
physical, sensory, or mental capabilities, or lack of experience and knowledge,
unless they have been given supervision or instruction concerning use of the
appliance by a person responsible for their safety.
• Children should be properly supervised around this appliance.
• Do not climb, stand, or hang on the appliance or door or allow children or animals
to do so. Do not climb into the appliance or allow children or animals to do so.
Death or serious injury could occur or the appliance could be damaged.
• Be careful not to pinch ngers when opening and closing the doors or rail cover
(prep table models). Be careful when opening and closing the doors or rail cover
when children are in the area.
• Open and close the doors and rail cover (prep table models) with care. Opening
the doors or rail cover too quickly or forcefully may cause injury or damage to the
appliance or surrounding equipment.
• Do not use combustible spray or place volatile or ammable substances in or near
the appliance. They might catch re.
• Keep the area around the appliance clean. Dirt, dust, or insects in the appliance
could cause harm to individuals or damage to the equipment.
• Do not throw anything onto the shelves or load any single shelf with more than
120lb. (54.5 kg) of product. They might fall off and cause injury.
• This appliance is designed only for temporary storage of food. Employ sanitary
methods. Use for any other purposes (for example, storage of chemicals or
medical supplies such as vaccine and serum) could cause deterioration of stored
items.
• Do not block air inlets or outlets, otherwise cooling performance may be reduced.
• Do not tightly pack the cabinet. Allow some space between items to ensure good
air ow. Also allow space between items and interior surfaces.
• Do not put warm or hot foods in the cabinet. Let them cool rst, or they will raise
the cabinet temperature and could deteriorate other foods in the cabinet or
overload the appliance.

7
WARNING, continued
• All foods should be wrapped in plastic lm or stored in sealed containers.
Otherwise foods may dry up, pass their smells onto other foods, cause frost
to develop, result in poor appliance performance, or increase the likelihood of
cross-contamination. Certain dressings and food ingredients, if not stored in
sealed containers, may accelerate corrosion of the evaporator, resulting in failure.
• Do not store items near air outlets. Otherwise, items may freeze up and crack or
break causing a risk of injury or contamination of other food.
Additional Warnings for Prep Table Models
• The entire rail must always be covered by rail dividers and pans (1/6 size, up to
6"(15cm)deep). Otherwise, the appliance will not cool properly.
• Use only 1/6 size pans up to 6"(15cm) deep. Do not use damaged pans.
• Ingredients must be pre-chilled to 37°F (3°C) or less before placing in rail.
• Keep the rail cover closed when not actively preparing food.
• The rail is for keeping ingredients cool while preparing food. If not actively
preparing food for a long period such as overnight, seal pans with plastic
wrap in addition to closing the rail cover. Depending on conditions, the cabinet
temperature setting may need to be adjusted to prevent items from freezing.
Alternatively, seal ingredients and store them in a refrigerator or freezer.
NOTICE
• Protect the oor when moving the appliance to prevent damage to the oor.
• Keep ventilation openings, in the appliance enclosure or in the built-in structure,
clear of obstruction. Do not place anything on top of the appliance in an
undercounter installation. There must be at least 1.5" (4 cm) overhead clearance
for proper ventilation. The factory-installed rear bumpers must be in place
to ensure proper rear clearance. Blockage of airow could negatively affect
performance and damage the appliance.
• Do not allow the appliance to bear any outside weight.
• To prevent deformation or cracks, do not spray insecticide onto the plastic parts or
let them come into contact with oil.
• To avoid damage to the gasket, use only the door handle when opening and
closing.
• To avoid damage to the top seal, do not lift the appliance by the top panel or
remove the top panel.
Additional Notice for Prep Table and Mega Top Models
• Do not place anything on top of the rail hood or rail cover and do not lift the
appliance by the rail hood or rail cover. The rail hood and rail cover are not
designed to bear any outside weight.
• CRMR27-8(-12M) Auxiliary Code B-5 to C-7: Do not place anything on the air
distribution table beneath the pans. The air distribution table is not a load-bearing
surface.

8
I. Construction and Refrigeration Circuit Diagram
A. Construction
Power Cord
Compressor
Condenser Fan Motor
Condenser
Rear Panel
Defrost Timer:
Prep Table and
Freezer.
Verify Auxiliary
Code in Parts List
for Change
Thermometer
Door
Door Gasket
Nameplate
• Evaporator
• Evaporator Fan
• Evaporator Fan Shroud
Cabinet Temperature Control Dial
(Cabinet Thermostat/Thermistor)
Verify Auxiliary Code in Parts List
for Change
Pans
Rail Dividers
Upper Front Upper Rear
Lower Rear
Lower Front
Rail Cover
Air Distribution Table Panels
Undercounter, Worktop, Prep Table
Common Parts
Prep Table
Specic Parts
Model Shown: CRMF27
Model Shown: CRMR27-12M
Rail Hood
Cutting Board
CRMR27-8, CRMR27-12M
Auxiliary Codes B-5 to C-7
Model Shown: CRMR36-10
Control Module:
Verify Auxiliary Code in
Parts List for Change

9
B. Refrigeration Circuit Diagram
1. Refrigerator and Freezer
Evaporator Fans
(1, 2, or 3 depending on model) Evaporator
Compressor
Drier
Condenser Fan
Condenser
Freezer and Prep Table Models: Defrost Heater, Defrost Safety Thermostat, and Defrost Thermistor
Cabinet Thermostat Bulb
Capillary Tube
High-Pressure Switch
CRMR60 and CRMR72 Prep Table,
CRMF48, and CRMF60
Thermostatic
Expansion Valve
CRMF48(-W)
Auxiliary Code: A-5 and B-5

10
II. Sequence of Operation and Service Diagnosis
The steps in the sequence are as outlined below.
See the table for default cabinet temperature control settings.
Model Default Cabinet Temperature
Control Setting
Approximate Default Temperature
Undercounter
Worktop
Between 4 and 5 Refrigerator: 34°F (1°C)
Freezer: -5°F (-21°C)
Prep Table 6 34°F (1°C)
A1. Thermostat Control Sequence of Operation Flow Chart
1. Undercounter and Work Top: Refrigerator
Refrigerator Sequence Flow Chart
1. Startup/Cool Down 2. Cool Down Achieved
CTh closed
Comp energized
ConFM energized
EvapFM energized
CTh open
EvapFM energized CRMR60 and CRMR72
Comp de-energized
ConFM de-energized
EvapFM de-energized CRMR27 and CRMR48
CTh in control
CTh above setpoint CTh cools to setpoint
CTh above setpoint
Off cycle defrost
between run cycles.
Legend:
Comp-compressor
ConFM-condenser fan motor
CTh-cabinet thermostat
EvapFM-evaporator fan motor

11
2. Prep Table
Prep Table/Mega Top Sequence Flow Chart
2. Cool Down 3. Cool Down Achieved
CTh closed
Comp energized
ConFM energized
EvapFM energized
(with DH)
CTh open
EvapFM energized
Comp de-energized
ConFM de-energized
4. Defrost
8 or 6-hr. DT terminates
20 or 25-min. DT starts
DH de-energized (if applicable)
CTh above setpoint CTh cools to setpoint
CTh above setpoint CTh above setpoint
20 or 25 min. DT in
control
CTh in control
1. Startup
EvapFM energized
(without DH)
8 or 6-hr. DT terminates
20 or 25-min. DT starts
DH energized
EvapFM energized (without DH)
Comp de-energized
ConFM de-energized
EvapFM de-energized (with DH)
Legend:
Comp-compressor
ConFM-condenser fan motor
CTh-cabinet thermistor
DH-defrost heater
DTh-defrost thermistor
EvapFM-evaporator fan motor
MH-mullion heater
PH-perimeter heater
Freezer Sequence Flow Chart
1. Startup/Cool Down 2. Cool Down Achieved
CTh closed
Comp energized
ConFM energized
EvapFM energized
MH energized
PH energized
CTh open
Comp de-energized
ConFM de-energized
EvapFM de-energized
MH de-energized
PH de-energized
3. Defrost
8 or 6-hr. DT terminates
20 or 25-min. DT starts
DH energized
Comp de-energized
ConFM de-energized
EvapFM de-energized
MH de-energized
PH de-energized
20 or 25-min. DT terminates
8 or 6-hr. DT starts
DH de-energized
CTh in control
CTh above setpoint CTh cools to setpoint
CTh above setpoint
CTh above setpoint
DT* in control
Legend:
Comp-compressor
ConFM-condenser fan motor
CTh-cabinet thermistor
DH-defrost heater
DTh-defrost thermistor
EvapFM-evaporator fan motor
MH-mullion heater
PH-perimeter heater
3. Undercounter and Work Top: Freezer

12
A2. Thermistor/Control Module Sequence of Operation Flow Chart
1. Undercounter and Work Top: Refrigerator
1. Startup/Cool Down 2. Cool Down Achieved
Comp energized
ConFM energized
EvapFM energized
Comp de-energized
ConFM de-energized
EvapFM de-energized
CTh in control
Off cycle defrost
between run cycles
Refrigerator Sequence Flow Chart
2-min. Comp
on timer starts
2-min. Comp
off timer starts
Legend:
Comp-compressor
ConFM-condenser fan motor
CTh-cabinet thermistor
EvapFM-evaporator fan motor
Power on
Red LED On
(5 sec. Delay)
Green LED Flashes
If Red LED ashes, check CTh
Green LED Flashes
If Red LED ashes, check CTh
CTh above setpoint CTh cools to setpoint
CTh above setpoint
Note: Delays
a) 2-min. minimum Comp on timer starts when Comp energizes.
b) 2-min. minimum Comp off timer starts when Comp de-energizes.
*
*
*

13
2. Prep Table
Prep Table Top Sequence Flow Chart
2. Cool Down 3. Cool Down Achieved
Comp energized ConFM energized EvapFM energized
EvapFM energized Comp de-energized ConFM de-energized
4. Defrost
CTh above setpoint CTh cools to setpoint
CTh above
setpoint
44°F (6.7°C)
achieved
CTh in control
1. Startup
EvapFM energized 6-hr. DT terminates
5-min. min. DT starts 25-min. max. DT starts DH energized Comp de-energized ConFM de-energized EvapFM de-energized
Defrost: time/temp. initiated temp. terminated
Power on Red LED On (5 sec. Delay)
Red LED Off Green LED Flashes If Red LED Flashes, check CTh or DTh
Legend: Comp-compressor ConFM-condenser fan motor CTh-cabinet thermistor DH-defrost heater DTh-defrost thermistor EvapFM-evaporator fan motor
Note: Delays
a) 2-min. minimum Comp on timer starts when Comp energizes. b) 2-min. minimum Comp off timer starts when Comp de-energizes. c) 5-min. minimum defrost time. d) 25-min. maximum defrost time. e) DOT (drip off time) 1-min. Comp/ConFM delay timer starts when defrost termination temperature is met (drip off time (DOT)). f) FDD (fan delay after defrost) EvapFM starts once 30-sec. EvapFM delay timer terminates or DTh reaches 40°F (4.4°C).
g) If evaporator temperature raises above 50°F (10°C) during the cooling cycle, 6-hr. DT resets.
*
2-min. Comp off timer starts
2-min. Comp on timer starts
Evap. Temp. reaches 44°F (6.7°C) DH de-energized 6-hr DT starts After DOT Delay: Comp energized ConFM energized After FDD EvapFM energized
*
*
*
*
*
*
DTh in control

14
3. Undercounter and Work Top: Freezer
Freezer Sequence Flow Chart
Legend: Comp-compressor ConFM-condenser fan motor CTh-cabinet thermistor DH-defrost heater DTh-defrost thermistor EvapFM-evaporator fan motor MH-mullion heater PH-perimeter heater
1. Startup/Cool Down 2. Cool Down Achieved
Comp energized ConFM energized EvapFM energized MH energized PH energized
CTh in control
Setpoint Achieved CTh warms
above setpoint
3. Defrost
Comp de-energized ConFM de-energized EvapFM de-energized MH de-energized PH de-energized
5. Defrost Termination
DTh in control
2-min. Comp off timer starts
2-min. Comp on timer starts
6-hr. or 8-hr. DT starts
Defrost Termination: Temp. achieved: 45°F (7°C) or 50°F (°10C)
6-hr. or 8-hr. DT terminates Evap. temp. below 41°F (5°C) 5-min. min. DT starts 60-min. max. DT starts DH energized Comp de-energized ConFM de-energized EvapFM de-energized
MH de-energized
PH de-energized
Defrost Initiation: Time/Temp achieved.
Note: Delays
a) 2-min. minimum Comp on timer starts when Comp energizes. b) 2-min. minimum Comp off timer starts when Comp de-energizes. c) 5-min. minimum defrost time. d) 1-hr. maximum defrost time. e) DOT (drip off time) 3-min. Comp/ConFM delay timer starts when defrost termination temperature is met (drip off time (DOT)). f) FDD (fan delay after defrost) EvapFM starts once 7-minute EvapFM delay timer terminates or DTh reaches 25°F (-4°C).
*
DH de-energized 6-hr. or 8-hr. DT starts After DOT Delay: Comp energized ConFM energized MH energized PH energized After FDD EvapFM energized
*
*
Defrost Terminated
6-hr. or 8-hr. DT terminates
Evap. temp. below 41°F (5°C)
Power on Red LED On (5 sec. Delay)
Red LED off Green LED Flashes If Red LED ashes, check CTh or DTh

15
B1. Thermostat Control Service Diagnosis
WARNING
• The appliance should be diagnosed and repaired only by qualied service
personnel to reduce the risk of death, electric shock, serious injury, or re.
• Risk of electric shock. Use extreme caution and exercise safe electrical practices.
• Moving parts (e.g., fan blade) can crush and cut. Keep hands clear.
• Make sure all food zones are clean after the appliance is serviced.
The diagnostic procedure is a sequence check that allows you to diagnose the electrical
system and components. Before proceeding, check for correct installation and proper
voltage per nameplate.
See the table for default cabinet temperature control settings.
Model Default Cabinet Temperature
Control Setting
Approximate Default Temperature
Undercounter
Worktop
Between 4 and 5 Refrigerator: 34°F (1°C)
Freezer: -5°F (-21°C)
Prep Table 6 34°F (1°C)
Note: When checking voltage (115VAC), always choose a white (W) neutral wire to
establish a good neutral connection.
1. Undercounter and Worktop: Refrigerator
1) Unplug the appliance from the electrical outlet.
2) Remove the rear panel.
3) Plug the appliance back into the electrical outlet.
4) Startup/Cool Down–Temperature above setpoint. CTh closed. Comp, ConFM, and
EvapFM energize. Diagnosis: Conrm that Comp, ConFM, and EvapFM energize.
Ifnot, conrm that temperature is above setpoint and CTh is closed. Check both
terminals of CTh (BK) or (BR) to a neutral (W) for 115VAC. If 115VAC is present on
one terminal and not the other, replace CTh. If 115VAC is present on both terminals,
Check voltage at Comp, external protector, and Comp terminals. Check Comp winding
continuity. Check voltage on ConFM and EvapFM. Check ConFM and EvapFM winding
continuity and check fan blades for binding.
If Comp, ConFM, and EvapFM are energized and the cabinet temperature does not
cool down, check for a restriction in the refrigeration circuit, low refrigerant charge, or
inefficient Comp.5)
5) Cool Down Achieved–Temperature cools to setpoint. CThopens. Comp, ConFM, and
EvapFM de-energize. Note: EvapFM continues on CRMR60 and CRMR72.
Diagnosis: If temperature has cooled to setpoint and Comp and ConFM do not
de-energize, check CTh continuity. If CTh defective, replace CTh.
Note: EvapFM de-energizes with Comp on CRMR27 and CRMR48 and continues on
CRMR60 and CRMR72.

16
2. Prep Table
1) Unplug the appliance from the electrical outlet.
2) Remove the rear panel.
3) Plug the appliance back into the electrical outlet.
4) Startup/Cool Down–Temperature above setpoint. CTh closed. Comp, ConFM, and
EvapFM energize. Diagnosis: Check that Comp, ConFM, and EvapFM energize.
Ifnot, conrm that the appliance is not in a defrost cycle. DT is operating properly,
temperature is above setpoint, and CTh is closed. Check voltage on DT. In cooling,
115VAC is present on both DT terminal #1 (BK) and DT terminal #4(BK) or (BR) to a
neutral (W). If 115VAC is present on terminal #2 (R) to a neutral (W), advance DT out
of defrost cycle or replace DT. Check both terminals of CTh (BK) or (BR) to a neutral
(W) for 115VAC. If 115VAC is present on one terminal and not the other, replace CTh.
If115VAC is present on both terminals, check for voltage at Comp, external protector,
and Comp terminals. Check Comp winding continuity. Check voltage on ConFM and
EvapFM. Check ConFM and EvapFM winding continuity and fan blades for binding.
Note: CRMR60-xx and CRMR72-xx, also see "HPS Activation (CRMR60 and CRMR72
Prep Table)" below.
If Comp, ConFM, and EvapFM are energized and the cabinet temperature does not
cool down, check for a restriction in the refrigeration circuit, low refrigerant charge, or
inefficient Comp.
HPS Activation (CRMR60 and CRMR72 Prep Table): Check continuity of HPS.
If open, allow time for system pressure to equalize and HPS to reset. If HPS does
not reset, replace HPS and diagnose reason for HPS activation. Conrm ConFM is
energized and fan blade turns freely. Check that the condenser coil is not clogged or
restricted. Check that there are no restrictions in the refrigeration circuit (drier).
Conrm that the appliance location meets factory requirements:
• This appliance is not intended for outdoor use. Normal operating ambient temperature
should be within 45°F to 100°F (7°C to 38°C).
• The appliance should not be located next to ovens, grills, or other high heat producing
equipment.
6) Cool Down Achieved–Temperature cools to setpoint. CTh opens. EvapFM continues.
Comp and ConFM de-energize. Diagnosis: If cabinet temperature has cooled to
setpoint and Comp and ConFM do not de-energize, check CTh continuity. If CTh
defective, replace CTh.
7) Defrost–Defrost Initiation: DT terminates. EvapFM continues (auxiliary code C-5 and
earlier). If CTh closed, Comp and ConFM de-energize. EvapFM de-energizes (auxiliary
code C-6 and later) and DH energizes (CRMR48-xx aux. code C-7 and later. All others
aux. code D-8 and later).
Defrost Termination: DT terminates. EvapFM continues (auxiliary code C-5 and earlier).
If CTh closed, Comp and ConFM energize. EvapFM energizes (auxiliary code C-6
and later) and DHde-energizes (CRMR48-xx aux. code C-7 and later. All others aux.
code D-8 and later).

17
Diagnosis: Defrost Initiation: Manually advance DT cam to terminate DT. Conrm
Comp and ConFM de-energize or remain de-energized and on auxiliary code C-6
and later, conrm EvapFM de-energizes. For CRMR48-xx aux. code C-7 and later
and all other aux. code D-8 and later, conrm DH energizes. If not, replace DT.
Defrost Termination: Advance DT cam to terminate DT. If CTh closed, conrm Comp
and ConFM energize and on auxiliary code C-5 and earlier, conrm EvapFM
energizes. For CRMR48-xx aux. code C-7 and later and all other aux. code D-8 and
later, conrm DH de-energizes. If not, check DT voltage terminal #2(R) to a neutral
(W). If115VAC is present, replace DT.
3. Undercounter and Worktop: Freezer
4) Startup/Cool Down–Temperature above setpoint. CTh closed. Comp, ConFM,
EvapFM, PH, and MH energize. Diagnosis: Check that Comp, ConFM, EvapFM,
PH, and MH energize. If not, conrm that the appliance is not in a defrost cycle, DT is
operating properly, temperature is above setpoint, and CTh is closed. Check voltage
onDT. In cooling, 115VAC is present on both DT terminal #1 (BK) and DT terminal
#4 (BK) to a neutral (W). If 115VAC is present on terminal #2 (R) to a neutral (W),
advance DT out of defrost cycle or replace DT. Check both terminals of CTh (BK) to a
neutral (W) for 115VAC. If 115VAC is present on one terminal and not the other, replace
CTh. If 115VAC is present on both terminals, check Comp, ConFM, and EvapFM. For
CRMF48(-01)(-W)(-W01) and CRMF60(-W), also see "HPS Activation (CRMF48(-01)
(-W)(-W01) and CRMF60(-W))" below.
Check voltage at Comp, external protector, and Comp terminals. Check Comp windings.
Check voltage on ConFM and EvapFM. Check ConFM and EvapFM windings. Check
fan blades for binding.
If Comp, ConFM, and EvapFM are energized and the cabinet temperature does not
cool down, check for a restriction in the refrigeration circuit, low refrigerant charge,
inefficient Comp, or defective TXV (CRMF48(-01)(-W)(-W01) auxiliary codes A-5 and
B-5).
HPS Activation (CRMF48 and CRMF60): Check continuity of HPS. If open, allow time
for system pressure to equalize and HPS to reset. If HPS does not reset, replace HPS
and diagnose reason for HPS activation. Conrm ConFM is energized and fan blade
turns freely. Check that the condenser coil is not clogged or restricted. Check that there
are no restrictions in the refrigeration circuit (drier, TXV (auxiliary codes A-5 and B-5)).
Conrm that the appliance location meets factory requirements:
• This appliance is not intended for outdoor use. Normal operating ambient temperature
should be within 45°F to 100°F (7°C to 38°C).
• The appliance should not be located next to ovens, grills, or other high heat producing
equipment.
• A minimum of 1.5" (4 cm) overhead clearance should be provided for proper
ventilation.
5) Cool Down Achieved–Temperature cools to setpoint. CTh opens. Comp, ConFM,
EvapFM, PH, and MH de-energize. Diagnosis: If temperature has cooled to setpoint
and Comp, ConFM, EvapFM, PH, and MH do not de-energize, check CTh continuity.
IfCTh defective, replace CTh.

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6a) Defrost
Early DT's were designed with 8-hr. interval and 20-min. defrost cycle.
Later DT's were designed with 6-hr. interval and 25-min. defrost cycle.
Manual advance in and out of defrost by turning the defrost dial is quickest way to
troubleshoot components.
Defrost Initiation: DT terminates. DH energizes. If CTh closed, Comp, ConFM,
EvapFM, PH, and MH de-energize.
Defrost Termination: DT terminates. DH de-energizes. If CTh closed, Comp, ConFM,
EvapFM, PH, and MH energize.
Diagnosis: Defrost Initiation: Manually advance DT cam to terminate DT. Conrm DH
energizes and Comp, ConFM, EvapFM, PH, and MH de-energize. If not, replace
DT. If Comp, ConFM, EvapFM, PH, and MH de-energize, check DH. Conrm DST is
closed. If not, let DH cool, then recheck DST. If DST is still open, replace DST. Check
DH amp draw and DH continuity.
Defrost Termination: Advance DT cam to terminate DT. If CTh closed, conrm Comp,
ConFM, EvapFM, PH, and MH energize. Conrm DH de-energizes. If not, check DT
voltage terminal #2 (R) to a neutral (W). If 115VAC is present, replace DT.
7) PH and MH Diagnosis: Check that PH and MH energize. Check for 115VAC at PH and
MH. If 115VAC is not present, check power supply. If 115VAC is present, check amp
draw of PH and MH. If an amp reading is not present, check the continuity of PH and
MH. If defective, replace PH or MH.
Legend: Comp–compressor; ConFM–condenser fan motor; CTh–cabinet thermostat;
DH–defrostheater; DST–defrost safety thermostat; DT–defrost timer;
EvapFM–evaporator fan motor; HPS–high-pressure switch; MH–mullion heater;
PH–perimeterheater; TXV–thermostatic expansion valve

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B2. Thermistor/Control Module Service Diagnosis
WARNING
• The appliance should be diagnosed and repaired only by qualied service
personnel to reduce the risk of death, electric shock, serious injury, or re.
• Risk of electric shock. Use extreme caution and exercise safe electrical practices.
• Moving parts (e.g., fan blade) can crush and cut. Keep hands clear.
• Appliance is heavy. Use care when lifting or positioning. Work in pairs when
needed to prevent injury or damage.
• Make sure all food zones are clean after the appliance is serviced.
The diagnostic procedure is a sequence check that allows you to diagnose the electrical
system and components. Before proceeding, check for correct installation and proper
voltage per nameplate.
See the table for default cabinet temperature control settings.
Model Default Cabinet Temperature
Control Setting
Approximate Default Temperature
Undercounter
Worktop
Between 4 and 5 Refrigerator: 34°F (1°C)
Freezer: -5°F (-21°C)
Prep Table 6 34°F (1°C)
The diagnostic procedure is a sequence check that allows you to diagnose the electrical
system and components. Before proceeding, check for correct installation and proper
voltage per nameplate.
Conrm that the appliance location meets factory requirements:
• This appliance is not intended for outdoor use. Normal operating ambient
temperature should be within 45°F to 86°F (7°C to 30°C).
• The appliance should not be located next to ovens, grills, or other high heat
producing equipment. Check CM using the steps in "II.C. Control Module Check."
Note: • When checking voltage (115VAC), always choose a white (W) neutral wire to
establish a good neutral connection.
• CM has high and low voltage protection. If off on either protection, no LED is
visible and all components are off.
High Voltage: 135VAC
Low Voltage: 90VAC
• Solid red LED for 5 sec. at startup.
• Flashing green LED: Normal operation.
• Flashing red LED: check cabinet thermistor and defrost thermistor (if applicable).
• CM has a 2 min. minimum on time and 2 min. minimum off time for Comp.
1. Service Diagnosis: All Refrigerators, Prep Tables, and Freezers
1) Unplug the appliance from the electrical outlet.
2) Remove the rear panel.

20
3) Plug the appliance back into the electrical outlet. If appliance was in defrost when power
supply was disconnected, defrost is terminated and normal cooling cycle begins when
power supply is reconnected.
4) Startup/Cool Down–There is a slight delay (solid red LED for 5 sec., then ashing
green LED). Temperature above setpoint at CTh and if applicable, conrm appliance is
not in a defrost cycle (PT and Freezers). Comp, CondFM, and EvapFM energize. 2-min.
Comp on timer starts.
Freezers: PH, and MH energize.
a) CTh Diagnosis: If CTh fails, a red LED ashes along with the green LED on the CM.
Conrm CTh is properly connected to CM. Check Ohm reading of CTh. Replace as
needed.
b) TD Diagnosis: Conrm TD is set between 4 and 5. Check Ohm reading of TD.
Replace as needed.
c) CM Diagnosis: Conrm green LED is ashing. If not, check for 115VAC between
CM 2 (L) black (BK) wire and CM 3 white (W) neutral wire. If 115VAC is not present,
check power cord connections and breaker/fuse. Conrm wiring connections are
secure for both CM 2 (L) black (BK) (power supply) and CM 3 white (W) (neutral).
If 115VAC is present and green LED is not ashing, replace CM.
d) Comp/CondFM Diagnosis:Check that Comp and ConFM energize. If not, conrm
that the temperature is above setpoint. Next, check for 115VAC at CM (C) 1 brown
(BR) wire to neutral (W) wire. If 115VAC is not present, replace CM. If 115VAC is
present, check HPS continuity (if applicable). See "f) HPS Activation" below.
Comp: If 115VAC is present, check Comp external overload, start cap, start relay, and
Comp motor windings. Replace as needed.
CondFM: If 115VAC is present, check fan blade for binding, then check ConFM motor
windings.
e) EvapFM Diagnosis: Check that EvapFM(s) energize. If not, check for 115VAC at
CM (F) 5 dark blue (DBU) wire to neutral (W) wire. If 115VAC is not present, replace
CM. If 115VAC is present, check fan blades for binding, then check EvapFM motor
windings.
f) HPS Activation (CRMR60 and CRMR72 Prep Table and Freezer Models):
Check continuity of HPS. If open, allow time for system pressure to equalize and
HPS to reset. If HPS does not reset, replace HPS and diagnose reason for HPS
activation. Conrm ConFM is energized and fan blade turns freely. Check that the
condenser coil is not clogged or restricted. Check that there are no restrictions in the
refrigeration circuit (drier).
g) PH and MH Diagnosis (Freezer only): PH and MH follow Comp operation. When
Comp is energized, PH and MH are energized. If 115VAC is present, check amp draw
of PH and MH. If an amp reading is not present, check the continuity of PH and MH.
If defective, replace PH or MH.
If Comp, ConFM, and EvapFM are energized and the cabinet does not cool down,
check for a restriction in the refrigeration circuit, low refrigerant charge, or inefficient
Comp.