Hoshizaki Steelheart UR/WR27B Series User manual

Models
Undercounter
Worktop
Prep Table
Refrigerated Kitchen Equipment
Steelheart B Series
Service Manual
Number: 73247
Issued: 3-22-2021
Revision: 7-6-2022
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 ................................................................................................. 4
I. Construction and Refrigeration Circuit Diagram ................................................................. 8
A. Construction.................................................................................................................. 8
B. Refrigeration Circuit Diagram...................................................................................... 10
II. Sequence of Operation and Service Diagnosis................................................................11
A. Sequence of Operation Flow Chart..............................................................................11
1. UR/WR: Refrigerator ...............................................................................................11
2. SR: Refrigerator..................................................................................................... 12
3. UF/WF: Freezer ..................................................................................................... 13
B. Service Diagnosis ....................................................................................................... 14
1. Diagnostic Procedures ........................................................................................... 15
C. Control Module Check................................................................................................. 20
D. Thermistor Check........................................................................................................ 23
E. Diagnostic Table.......................................................................................................... 24
III. Controls and Adjustments............................................................................................... 27
A. Temperature Settings .................................................................................................. 27
B. Defrost......................................................................................................................... 28
C. Safety Devices ............................................................................................................ 29
D. Perimeter and Mullion Heaters (UF/WF only).............................................................. 29
IV. Refrigeration Circuit and Component Service Information.............................................. 30
A. Refrigeration Circuit Service Information .................................................................... 32
B. Component Service Information.................................................................................. 35
V. Preparing the Appliance for Periods of Non-Use ............................................................. 36
VI. Disposal.......................................................................................................................... 37
VII. Technical Information..................................................................................................... 38
A. Electrical and Refrigerant Data ................................................................................... 38
B. Wiring Diagrams.......................................................................................................... 39
1. UR/WR27, UR/WR36, UR/WR48 (except glass door), and SR36.......................... 39
2. UF/WF27, SR27, and SR48.................................................................................... 40
3. UR/WR48 (glass door), UR/WR60, and UR/WR72............................................... 41
4. UF/WF48, UF/WF60, SR60, and SR72................................................................. 42

4
DANGER
Risk of Fire or Explosion
Flammable Refrigerant Used
• Follow handling instructions carefully
in compliance with U.S. government
regulations.
• Do not use mechanical devices to defrost.
• Do not puncture refrigerant tubing. Risk
of re or explosion due to puncture
of refrigerant tubing; follow handling
instructions carefully.
• Component parts shall be replaced with
like components.
• Servicing shall be done by factory
authorized service personnel to minimize
the risk of possible ignition due to incorrect
parts or improper service.
• Consult instruction manual/service manual
before attempting to install or service this
product. All safety precautions must be
followed.
• Dispose of properly in accordance with
federal or local regulations.
• Do not place any potential ignition sources
in or near the appliance.
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.
DANGER Indicates a hazardous situation that, if not avoided, will result in
death or serious injury.
WARNING Indicates a hazardous situation that, if not avoided, could result
in death or serious injury.
NOTICE Indicates a situation that, if not avoided, could result in damage
to the appliance or property.
IMPORTANT Indicates important information about the use and care of the
appliance.
Risque De Feu Ou D'Explosion
Le Frigorigène Est Inammable
• Suivre attentivement les instructions
de manipulation conformément à la
réglementation gouvernementale.
• Ne pas utiliser d'appareils mécaniques
pour dégivrer le réfrigérateur.
• Ne pas perforer la tubulure contenant le
frigorigène. Risque de feu ou d'explosion
si la tubulure contenant le frigorigène
est perforée; suivre les instructions de
manutention avec soin.
• Les pièces des composants doivent être
remplacées par des pièces et accessoires
équivalents.
• L’entretien doit être effectué par le
personnel de service autorisé par le
fabricant an de minimiser les risques
d’inammation attribuables à l’installation
d’une pièce inadéquate ou à la mauvaise
exécution du service.
• Consulter le manuel du propriétaire/
guide de réparation avant de tenter une
réparation. Toutes les mesures de sécurité
doivent être respectées.
• Éliminer conformément aux règlements
fédéraux ou locaux.
• Ne placez aucune source d’inammation
potentielle dans ou près de l’appareil.

5
WARNING
The 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 install,
operate, 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 the appliance.
• Wear appropriate personal protective
equipment (PPE) when servicing the
appliance.
• The appliance must be installed in
accordance with applicable national, state,
and local codes and regulations.
• Appliance is heavy. Use care when lifting
or positioning. Work in pairs when needed
to prevent injury or damage. Do not lift
using the top section or the doors/drawers.
• To reduce the risk of electric shock, do not
touch the plug with damp hands.
• Unplug the appliance before servicing.
• The 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.
• THE APPLIANCE MUST BE
GROUNDED. The 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.
• 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.
• The 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.

6
• 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.
• Food storage and handling must comply with
applicable codes and regulations.
• 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.
WARNING, continued
• Children should be properly supervised
around the appliance.
• Do not climb, stand, or hang on the
appliance or doors/drawers 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/drawers or
rail cover (SR models) or when handling
food pans. Be careful when opening and
closing the doors/drawers or rail cover
when children are in the area.
• Open and close the doors/drawers and rail
cover (SR models) with care. Opening the
doors/drawers 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.
• Do not load any single drawer with more
than 75 lb. (34 kg) of product. Depending
on the weight of product in the drawers,
secure the unit as necessary to prevent it
from overturning. Do not open more than
one drawer at a time.
• The 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.

7
WARNING, continued
Additional Warnings for SR 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/drawer 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 SR 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.

8
I. Construction and Refrigeration Circuit Diagram
A. Construction
1. Solid Door Models
Compressor Condenser Fan Motor
Condenser
Rear Panel
Thermometer
Door
Door Gasket
Nameplate
• Evaporator
• Evaporator Fan
• Evaporator Fan Shroud
Control Module with Cabinet
Temperature Control Dial
Model Shown: UR27B
Model Shown: UR27B

9
2. Glass Door Models
Compressor Condenser Fan Motor
Condenser
Rear Panel
Thermometer
Door
Door Gasket
Nameplate
• Evaporator
• Evaporator Fan
• Evaporator Fan Shroud
Control Module with Cabinet
Temperature Control Dial
Model Shown: UR27B-GLP01
LED Driver
Channel
Model Shown: UR27B-GLP01
LED Lights

10
B. Refrigeration Circuit Diagram
Evaporator Fans
(1, 2, or 3 depending on model)
Evaporator
Compressor
Drier
Condenser Fan
Condenser
SR and UF/WF Models: Defrost Heater
Capillary Tube
Cabinet Thermistor
Defrost Thermistor
Condensate Pan