Hotstart DLV User manual

216306-000 rev1
INSTALLATION & OPERATION MANUAL
DUAL FLUID CIRCULATING HEATING SYSTEM
MODEL
DLV

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i
installation & operation manual | dlv heating system
IOM216306-000
Corporate &
Manufacturing
Headquarters
Spokane, WA, USA
509.536.8660
[email protected]
Oil & Gas Ofce
Katy, TX, USA
281.600.3700
[email protected]
Railroad Ofce
Merrillville, IN, USA
+49.2241.12734.0
[email protected]
Europe Ofce
Koln, Germany
+49.2241.12734.0
[email protected]m
United Kingdom Ofce
Birmingham, UK
+49.2241.12734.0
[email protected]
Asia Pacic Ofce
Tokyo, Japan
+81.3.6902.0551
[email protected]
IDENTIFYING YOUR SYSTEM
The Hotstart heating system is designed to heat uids for use in marine propulsion, diesel-powered generator sets,
locomotives, gas compression or any large-engine applications. Each heating system has an identication plate which
includes the part number and serial number.
This operation manual describes the installation, operation and maintenance of the heating system. Model specics,
capabilities and features may vary. See part drawings for dimensions and specications.
When ordering replacement parts, be sure to reference your heating system’s model number
and serial number found on the identication plate and following label:
WARRANTY INFORMATION
Warranty information can be found at www.hotstart.com or by contacting our customer service department at
509.536.8660. Have your model number and serial number ready when contacting the warranty department.
COPYRIGHT
Hotstart Manufacturing, Inc. is the owner of all trademarks and copyrightable material contained herein; all rights are
reserved; no form of reproduction is authorized without prior written consent from Hotstart Manufacturing, Inc.
NOTE: Typical heating
system
identication
plate. Your
identication
plate may vary.

ii installation & operation manual | dlv heating system
IMPORTANT SAFETY
INFORMATION
WARNING
!
Hazardous voltage: Before wiring, servicing or cleaning
the heating system, turn off the power and follow your
organization’s lockout and tagout procedure. Failure
to do so could allow others to turn on the power
unexpectedly, resulting in harmful or fatal electrical
shock.
Electrical hazard: All electrical work must be done by
qualied personnel in accordance with national, state
and local codes.
CAUTION
!
Read instructions carefully: The safety of any system
incorporating this heater is the responsibility of the
assembler. The safe and proper use of this heater
is dependent upon the installer following sound
engineering practices. If the equipment is used in
a manner not specied by the manufacturer, the
protection provided by the equipment may be
impaired. All applicable electrical safety standards
dened by local jurisdictions must be followed.
(Reference EU directive 2006/95/EC in EU countries.)
• Read carefully: Installers and operators of
this equipment must be thoroughly familiar
with the instructions in this manual before
commencing work.
• Hot surfaces: Avoid contact with the
system while it is in service. Some surfaces
may remain hot even if the system is not
energized.
• Proper lifting: Proper rigging and safety
equipment must be used to move this
equipment. Do not lift the heating system
by any cords, electrical conduit or cabling.
Create a plan before attempting to move.
Proper lifting locations are identied on each
system; use these locations when lifting and
mounting the system.
• Rotating equipment: The heating system
can start automatically and without warning.
Avoid contact unless a lockout at the service
panel has been installed.
• Grounding: The heater must be connected
to a suitable ground (protective earthing
conductor).
• Overcurrent limiting: The power supply must
be protected by a suitable overcurrent
limiting device.
• Power disconnection: A means to
disconnect the heater from the power supply
is required. Hotstart recommends that a
power switch or circuit breaker be located
near the heater for safety and ease of use.
NOTICE
EU Countries only: Equipment rated for the conditions
listed in EN 601010-1 1.4.1 Ingress protection rating
IP55. (Special conditions for specic applications may
apply.)

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installation & operation manual | dlv heating system
TABLE OF CONTENTS
1 OVERVIEW | 1
1.1 HEATING SYSTEM COMPONENTS | 1
1.2 OPERATION OVERVIEW | 2
2 PLUMBING INSTALLATION | 3
2.1 OIL PLUMBING | 4
2.1.1 Oil Supply | 4
2.1.2 Oil Return | 4
2.1.3 Oil Pressure Relief Valve | 4
2.2 OIL PLUMBING ILLUSTRATION | 5
2.3 COOLANT PLUMBING ILLUSTRATION | 6
2.4 COOLANT PLUMBING | 7
2.4.1 Coolant Supply | 7
2.4.2 Coolant Return | 7
2.4.3 Coolant Pressure Relief | 7
2.5 MOUNTING | 8
2.5.1 Tanks and Pumps | 8
2.6 ELECTRICAL CONNECTIONS | 8
2.6.1 Main Power Supply | 8
2.6.2 Motor Rotation Check | 8
2.6.3 Customer Interface Connections | 9
3 SYSTEM COMPONENTS AND
OPERATION | 9
3.1 SYSTEM COMPONENTS | 9
3.1.1 Motor Protection Switch (MPS) | 9
3.1.2 High-Limit TCR (Temperature Control Relay) | 10
3.1.3 Control TCR (Temperature Control Relay) | 10
3.2 INTERFACE COMPONENTS | 10
3.2.1 On/Off/Prime Switch | 10
3.2.2 Pressure/Temperature Gauges | 10
3.2.3 Pressure Relief Valves | 10
3.3 HEATING SYSTEM START-UP | 11
3.3.1 First Run Procedure | 11
4 MAINTENANCE, REPAIR AND
TROUBLESHOOTING | 12
4.1 SYSTEM FAULTS | 12
4.1.1 Coolant Faults | 12
4.1.2 Oil Faults | 12
4.2 SYSTEM MAINTENANCE | 12
4.2.1 Plumbing Connections | 12
4.2.2 Electrical Connections | 12
4.2.3 System Mounting | 12
4.2.4 Magnetic Contactors | 12
4.2.5 Pump Seal | 12
4.2.6 Motor Lubrication | 13
4.2.7 Oil Pressure Relief Valve | 13
4.2.8 Pressure/Temperature Gauges | 13
4.2.9 Volatile Corrosion Inhibitor (VCI) | 13
4.2.10 Temperature Control Relay (TCR) | 14
4.2.11 Resistance Temperature Device (RTD) | 15
4.2.12 Heating Tank/Element | 16
4.2.13 Reassembly of Heating Element and Tank | 16
4.3 RECOMMENDED MAINTENANCE | 17
4.4 STORAGE REQUIREMENTS | 17
4.5 TROUBLESHOOTING | 18
5 APPENDIX | 19
5.1 INSTALLATION KITS | 19
5.1.1 Coolant & Oil Install Kit (Optional) | 20
5.1.1 Coolant & Oil Install Kit (Optional) | 21
5.1.2 DLV Installation Kit Parts List | 22

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iv installation & operation manual | dlv heating system

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installation & operation manual | dlv heating system
1 OVERVIEW
1.1 HEATING SYSTEM COMPONENTS
The heating system consists of the following main components: See Figure 1.
NOTE: Component illustrations are for reference only and are not to scale. See part drawings for dimensions
and specications.
Figure 1. DLV heating
system components.
A. Oil on/off/prime switch
B. oil fault light
C. Coolant on/off/prime switch
D. coolant fault light
E. Lift points
F. Check valve
G. Coolant outlet (1.0″ NPT)
H. Oil outlet (1.0″ NPT)
I. Coolant High-Limit RTD (resistance
temperature device)
J. Oil High-Limit RTD (resistance
temperature device)
K. Coolant pump/motor
L. Coolant pressure/temperature gauge
M. Coolant Control RTD (resistance
temperature device)
N. Oil Control RTD (resistance
temperature device)
O. Coolant pressure relief valve (0.5″ NPT)
P. Oil inlet (1.0″NPT)
Q. Coolant inlet (1.0″NPT)
R. Oil pump/motor
S. Identication plate
F
A
B
C
D
E
G
I
J
H
M
N
L
O
S
Q
P
K
R

2installation & operation manual | dlv heating system
1.2 OPERATION OVERVIEW
The DLV heating system is intended to maintain an engine’s optimal starting temperature and optimal lubrication oil
temperature while the engine is shut down. The heating system may be activated locally or by optional remote control
(see SECTION 2.6.3). The DLV heating system should be deactivated upon engine start-up.
During heating system operation, a centrifugal pump takes coolant from the drain area low on the engine water jacket
and forces it through the heating tank and into the coolant return line. Simultaneously, a rotary gear pump takes oil from
the sump and forces it through the heating tank to the oil return line. The coolant pump and oil pump will continuously
circulate uid throughout the engine. To maintain consistent uid temperature, the heating elements will cycle on and off
at the user-selected temperature control point.
A coolant check valve (included with the DLV unit and installed at the coolant outlet) and an oil check valve (user-supplied
and installed near the oil suction port) prevent backow while the engine is operating. When the engine is shut down, the
heating system should be activated locally or remotely to resume maintaining the engine’s optimal starting temperature.
Figure 2.
DLV operation
overview, showing
oil and coolant
circulation. While the
heating elements
cycle on and off to
maintain the preset
temperature, the
pumps circulate uid
continuously during
operation.
Component
illustrations are for
reference only and
are not to scale.
See part drawings
for dimensions and
specications.
OIL SUPPLY
COOLANT SUPPLY
COOLANT RETURN
OIL RETURN

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installation & operation manual | dlv heating system
2 PLUMBING INSTALLATION
CAUTION
!
Pressure hazard: Power must be turned off and locked out at the service panel when the isolation valves are in the
closed position. Failure to do so may cause damage to heating system components, damage to lubrication oil, uid
leaks and unexpected release of heated coolant.
Overheating hazard: After completing line installation, top off the uid levels to compensate for the uid used to ll
the lines and heating tank. Do not operate the heating system without the presence of uid. Position the heating tank
to ensure it is completely full of uid while in operation.
Pump priming: Fill each supply line with uid. Pump is not self-priming. Fluid must be present in the pump before start-
up. Trapped air inside the pump will cause pump and seal damage.
Pump seal damage: Do not reduce the coolant supply line or oil supply line to an inner diameter smaller than the
corresponding pump inlet; pump seal damage will occur.
Check valve: Hotstart recommends installing a customer-supplied swing-type or full-ow check valve to prevent
oil from owing back into the oil sump. If the pump is installed above the minimum oil level, a check valve must be
installed.
Isolation valves: Hotstart recommends installing full-ow ball valves to isolate the heating system in order to perform
service on the system or engine without draining oil or coolant.
Pressurized steam hazard: Coolant pressure relief valve outlet must be vented to the atmosphere in case an over-
pressure release of heated coolant occurs. Do not connect pressure relief plumbing to coolant system.
CAUTION
!
Lifting hazard: Proper rigging and safety equipment must be used to move this equipment. Do not lift the heating
system by any cords, electrical conduit or cabling. Create a plan before attempting to move. Proper lifting locations are
identied on each system; use these locations when lifting and mounting the system.
NOTICE
Heating system damage: Engine vibration will damage the heating system; isolate the heating system from vibration.
Never mount the heating system or components directly to the engine. If the heating system is installed using rigid
pipe, use a section of exible hose to the supply and return ports to isolate the heating system from engine vibration.
Improper mounting hazard: Reference heating system component drawings before mounting the system. Unless
mounted properly, the heating system will be unstable.

4installation & operation manual | dlv heating system
2.1 OIL PLUMBING
2.1.1 OIL SUPPLY
Installing a short, straight oil supply line with a minimum
of ow restriction is the most important step toward
ensuring heating system longevity. When installing
the DLV oil supply line, refer to the following Hotstart
guidelines (see SECTION 5.1 for optional coolant and
oil install kit components):
PUMP
INLET
HOSE INNER
DIAMETER
MAX. LINE
LENGTH
MAX. ELBOW
COUNT
1 inch
NPT 1-1/2 inch 20 feet (6 meters) 4
• Due to the increased viscosity of oil, the oil
supply line must be as short and as straight
as possible. Any 90° elbows will reduce the
maximum recommended oil supply length.
See Table 1 for Hotstart DLV oil supply
recommendations:
NOTE: Each additional pair of 90° elbows will reduce
the maximum recommended line length by ve
feet (1.5 meters). To minimize ow restriction,
Hotstart recommends using sweeping bends or
45° ttings.
• At a minimum, size the oil supply line per the
pump inlet. NOTICE! Do not reduce the
supply line inner diameter; pump seal
damage will occur.
NOTE: To maximize ow and allow the longest possible
supply line, install the largest practical inner
diameter hose; for most installations, Hotstart
recommends using a hose with a size larger
inner diameter than the pump inlet.
• Install the oil suction port as low as possible
in the oil tank. NOTICE! Avoid installing
the oil suction port in a location that may
allow debris or sediment to enter the
heating system.
• HOTSTART recommends installing a user-
supplied, swing-type or full-ow check valve
to prevent oil owing into the sump. Install
the check valve as close to the oil supply port
as possible.
2.1.2 OIL RETURN
When installing the DLV oil return line, refer to the
following Hotstart guidelines:
• At a minimum, size the oil return line per
the heating system outlet. NOTICE! Do not
reduce the return line inner diameter.
• Install the oil discharge port near the engine
oil pump, the opposite end of the oil sump or
at the lower P-pipe for railroad applications.
2.1.3 OIL PRESSURE RELIEF VALVE
The oil pump pressure relief valve is internal to the pump
and releases pressure from the discharge side of the
pump to the suction side of the pump at 75 psi (525 kPa).
No plumbing for this component is required.
B
A
Figure 4. Typical oil discharge port (A) installed at locomotive engine
lower P-pipe. Note coolant suction port (B) located at locomotive
main engine drain.
Table 1. HOTSTART recommended hose inner diameters, line
lengths and elbow counts for DLV oil supply lines.
Figure 3. Typical oil suction port installations for railroad applications:
near third inspection cover (above) and through cover (below).

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installation & operation manual | dlv heating system
2.2 OIL PLUMBING ILLUSTRATION
NOTE: Installation illustrations are for reference only and are not to scale. See part drawings for dimensions
and specications.
OIL RETURN
SECTION
2.1.2
OIL
DISCHARGE
PORT
SECTION 2.1.2
OIL SUCTION
PORT
SECTION 2.1.1
CHECK VALVE
SECTION 2.1.1
OIL SUPPLY
SECTION 2.1.1
ISOLATION
VALVES

6installation & operation manual | dlv heating system
2.3 COOLANT PLUMBING ILLUSTRATION
NOTE: Installation illustrations are for reference only and are not to scale. See part drawings for dimensions
and specications.
PRESSURE
RELIEF
VALVE
SECTION 2.4.3
COOLANT RETURN
SECTION 2.4.2
COOLANT
DISCHARGE
PORT
SECTION 2.4.2
COOLANT
SUCTION PORT
SECTION 2.4.1
COOLANT SUPPLY
SECTION 2.4.1
ISOLATION VALVES

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installation & operation manual | dlv heating system
2.4 COOLANT PLUMBING
2.4.1 COOLANT SUPPLY
When installing the DLV coolant supply line, refer to the
following HOTSTART guidelines (see SECTION 5.1 for
optional coolant and oil install kit components):
• At a minimum, size the coolant supply line
per the pump inlet. NOTICE! Do not reduce
the supply line inner diameter; pump seal
damage will occur.
NOTE: To maximize ow and allow the longest
possible supply line, install the largest
practical inner diameter hose; for most
installations, Hotstart recommends using a
hose with a size larger inner diameter than
the pump inlet.
• Install the coolant suction port as low as
possible on the engine’s water jacket, typically
near the main water drain. See Figure 5.
• To minimize ow restriction, the coolant
supply line must be as short and as straight
as possible. Use elbow ttings sparingly;
Hotstart recommends using sweeping bends
or 45° ttings.
2.4.2 COOLANT RETURN
When installing the DLV coolant return line, refer to the
following Hotstart guidelines:
• Size the coolant return line per the pump
outlet. NOTICE! Do not reduce the return
line inner diameter.
• Install the coolant discharge port as high as
possible on the engine’s water jacket on the
opposite end of the suction port; typically
near the aftercooler water line discharge port.
NOTE: To ensure even heat distribution, the coolant
return line may be split and routed to two
return ports. Size both return lines per the
outlet of the heating system. For engines
without an aftercooler, typical installation
points are along the water line from the
radiator to the engine block. See Figure 6.
2.4.3 COOLANT PRESSURE RELIEF
To safeguard personnel and equipment, attach an
appropriately sized pipe to the pressure relief valve and
route to a safe area, bucket or catch-basin. CAUTION!
Coolant pressure relief valve outlet must be plumbed to
a safe area in case an over-pressure release of heated
coolant occurs. Do not connect pressure relief plumbing
to coolant system.
Figure 6. Typical coolant discharge ports installed on a turbocharged
locomotive engine (above) and supercharged engine at Y-pipe
(below). To distribute heat evenly, the return line is split into two
discharge ports. Each port is installed at a welded 45° tting, angled
to ensure majority of heated coolant is transferred directly to engine
block. Note incorrectly oriented tting (inset). This tting should be
angled in the opposite direction to allow ow toward the engine.
AB
Figure 5. Coolant suction port installed at main locomotive engine
drain. Note suction port (A) has been installed at the same level as
the drain (B), ensuring DLV pump will draw water from the cooling
system’s lowest point.

8installation & operation manual | dlv heating system
2.5 MOUNTING
2.5.1 TANKS AND PUMPS
Mount the heater in a vertical orientation with pump
motor assemblies directly below control box. Reference
drawings for mounting position. When installing the
heating system, Hotstart recommends 30 inches (76
cm) of clearance to remove element for maintenance.
Reference part drawings for minimum clearance required
for your model. See SECTION 4.2.12.
2.6 ELECTRICAL CONNECTIONS
WARNING
!
Hazardous voltage: Before wiring, servicing or cleaning
the heating system, turn off the power and follow your
organization’s lockout and tagout procedure. Failure
to do so could allow others to turn on the power
unexpectedly, resulting in harmful or fatal electrical
shock.
Electrical hazard: All wiring shall be done by qualied
personnel in accordance with national, state and local
codes. Each system shall be grounded in accordance
with the National Electrical Code. Failure to properly
ground the system may result in electrical shock.
2.6.1 MAIN POWER SUPPLY
1. Connect the specied power from the user-
supplied circuit breaker to the terminal blocks
located in the main control box.
NOTE: The specied power source must be within
plus or minus 10% of the rated voltage.
NOTE: The circuit breaker must be near the
heating system and easily accessible.
Hotstart recommends connecting the
heating system to a circuit breaker rated for
125% of the system’s maximum load.
NOTE: The main power supply operates the
heating elements and the circulating
pumps. A transformer is used to operate
the control circuit. The transformer and
control circuits are overload-protected.
hFor three-phase applications, the terminal
blocks are labeled L1,L2 and L3.
hFor single-phase applications, use the terminal
blocks labeled L1 and L2 or L and N.
See Figure 9 on following page.
2. Connect the main power ground wire to the ground
lug or ground block on the electrical panel located
inside the electrical box.
2.6.2 MOTOR ROTATION CHECK
NOTICE
Pump rotation (three-phase only): For three-phase
applications, check for proper pump rotation prior to
introducing uid to the pump. Reverse rotation while
the pump is lled with uid will cause pump seal failure.
Pump damage: Do not run the motor/pump assembly
dry for more than a few seconds. Running a motor/
pump for a prolonged period without being completely
lled with uid may cause damage to the pump seal.
The following procedures are for three-phase
applications only. Single-phase systems are prewired to
ensure the pump motor rotates in the correct direction.
1. With main power connected to the heating system
motor (see SECTION 2.6.1), energize the pump
while observing the rotation of the pump motor fan
at the rear of the motor. Refer to rotation decal on
motor for correct rotation.
hIf the pump motor does not rotate in the correct
direction, disconnect power and switch any two
electrical leads at the main power terminal block
(L1, L2, L3). Reconnect power. Repeat step 1 to
ensure motor rotates in the correct direction.
J
A
Figure 7. DLV 0.438 inch (11.13 mm)
diameter mounting holes ×6 (A).
Mount unit in orientation shown. Do
not mount at an angle or in any other
orientation.
Figure 8. Underside
of DLV control box,
showing 1.25 ″NPT
main power entrance
(A) and 0.5 ″NPT
customer interface
wiring entrance (B).
J
A
B

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installation & operation manual | dlv heating system
2.6.3 CUSTOMER INTERFACE
CONNECTIONS
The following customer interface connections are
available for remote control and monitoring:
• Coolant Fault Signal
TB2:1/TB2:2 (C)
The fault signal will indicate a coolant
heating system shutdown, triggered by
either the high-limit temperature control
relay or the motor protection switch (see
SECTION 4.1.1).
• Coolant Motor Run Signal
TB2:3/TB2:4 (D)
A motor run signal indicates the coolant
pump motor is running. If no signal is present,
the pump motor is not running.
• Oil Fault Signal
TB2:5/TB2:6 (E)
The fault signal will indicate an oil heating
system shutdown, triggered by either
the high-limit temperature control relay
or the motor protection switch (see
SECTION 4.1.1).
• Oil Motor Run Signal
TB2:7/TB2:8 (F)
A motor run signal indicates the oil pump
motor is running. If no signal is present, the
pump motor is not running.
• Remote On/Off 24 V DC shutdown (G)
TB2:9/TB2:10
When activated, the remote on/off
connection shuts down the heating system.
When deactivated, normal heating will
resume. Use this connection for remote
operation of the heater when the local/
off/remote switch is turned to remote.
NOTE: The 24 V DC shutdown connection is
wired NC (normally closed) from the
factory; see system wiring schematic for
directions to switch to NO (normally open)
operation.
3 SYSTEM COMPONENTS
AND OPERATION
3.1 SYSTEM COMPONENTS
3.1.1 MOTOR PROTECTION SWITCH (MPS)
The motor protection switch (MPS) protects the pump
motor from overloads. See Figure 10 on the following
page. The MPS will be set at the full load amperage
of the motor when shipped from the factory. To reset
the MPS, the on/off/prime switch must be switched
to off and the operator must press the MPS reset/on
button. See SECTION 4.1.
AB
C D E F G
Figure 9. Main power supply and
customer interface connections
as shown in the DLV control box.
Reference electrical schematic
drawing for proper wiring locations;
the following illustrations are typical
customer interface locations.
A. Main power ground block
B. Main power terminal block
C. Coolant fault signal
D. Coolant motor run signal
E. Oil fault signal
F. Oil motor run signal
G. Remote On/Off 24 V DC
shutdown
21 22
21 22

10 installation & operation manual | dlv heating system
3.1.2 HIGH-LIMIT TCR (TEMPERATURE
CONTROL RELAY)
The high-limit TCRs (TCR2, TCR4) are protection devices
to prevent uid overheating. The high-limit TCR uses a
resistance temperature device (RTD) located near each tank
outlet. The default setting for the coolant and oil high-limit
TCRs is 194 °F (90 °C) at 0% hysteresis and should always be
at least 18 °F (10 °C) higher than the corresponding control
TCR set point. The high-limit TCR hysteresis is not used in
the high-limit control. See Figure 10.
3.1.3 CONTROL TCR (TEMPERATURE
CONTROL RELAY)
The control TCRs (TCR1, TCR3) are used to control the
temperature of the respective uids. The control TCRs
use a resistance temperature device (RTD) to sense the
temperature of the uid as it enters the heating tank. The
standard setting for the coolant control temperature relay
(TCR1) is 122 °F (50 °C) at 10% hysteresis. The standard
setting for the oil control temperature relay (TCR3) is
104 °F (40 °C) at 10% hysteresis. See Figure 10.
3.2 INTERFACE COMPONENTS
The following is an operation description for the standard
parts located in the system.
NOTE: Parts in the control box may vary depending on
the particular system conguration purchased.
3.2.1 ON/OFF/PRIME SWITCH
• on – The system is on. In this state, the 24
V DC shutdown may be used to activate or
deactivate the system.
• off – The system is shut off.
• prime – Turn and hold the switch to prime to
energize the corresponding pump motor in
order to remove any air in the heating system
without energizing the elements.
3.2.2 PRESSURE/TEMPERATURE
GAUGES
The DLV model features a temperature/pressure gauge
mounted at the outlet of each heating tank. The gauge
will indicate a pressure increase when the pump motor
is engaged by turning and holding the on/off/prime
switch to prime or during normal operation. The gauge
will also indicate the current uid temperature.
NOTE: Your system’s operating pressure may vary
depending on the conguration of the engine.
3.2.3 PRESSURE RELIEF VALVES
CAUTION
!
Pressurized steam hazard: Coolant pressure relief valve
outlet must be plumbed to a safe area in case an over-
pressure release of heated coolant occurs.
K1
K3
TCR2 TCR4
K4 K2
TCR1 TCR3
HIGHLIMIT
OIL
HIGHLIMIT
COOLANT
CONTROL
OIL
CONTROL
COOLANT
CD
A
B
K1
K3
TCR2 TCR4
K4 K2
TCR1 TCR3
HIGH LIMIT
OIL
HIGH LIMIT
COOLANT
CONTROL
OIL
CONTROL
COOLANT
MPS2 MPS1
01000100
CD
A
B
K1
K3
TCR2 TCR4
K4 K2
TCR1 TCR3
HIGH LIMIT
OIL
HIGH LIMIT
COOLANT
CONTROL
OIL
CONTROL
COOLANT
MPS2 MPS1
01000100
CD
A
B
K1
K3
TCR2 TCR4
K4 K2
TCR1 TCR3
HIGH LIMIT
OIL
HIGH LIMIT
COOLANT
CONTROL
OIL
CONTROL
COOLANT
MPS2 MPS1
01000100
Figure 10. DLV motor protection switch (below), showing reset/on (A)
and stop/off (B) buttons. To reset the MPS, the heating system must
be switched off and the MPS reset/on button must be pressed.
DLV control and high-limit TCRs (right). The standard setting for TCR1
control dial (C) is 122 °F (50 °C). The standard setting for TCR3 control
dial (D) is 104 °F (40 °C).

11
installation & operation manual | dlv heating system
The coolant pressure relief valve is mounted at the
coolant heating tank outlet and is set to relieve at 100
psi (690 kPa). During normal operation, pressure release
events are rare. To safeguard personnel and equipment,
attach an appropriately sized pipe to the pressure relief
valve outlet and direct ow to a safe area, bucket or
other catch-basin.
The oil pump pressure relief valve is internal to the pump
and releases pressure from the discharge side of the
pump to the suction side of the pump at 75 psi (525
kPa). No plumbing for this component is required. The
pressure relief valve cap must always point toward the
inlet side of the pump. When examining the pump, note
that the outlet will be designated by an installed screw.
See Figure 11.
3.3 HEATING SYSTEM START-UP
WARNING
!
Hazardous voltage: Before wiring, servicing or cleaning
the heating system, turn off the power and follow
your organization’s lockout and tagout procedure.
Failure to do so could allow others to turn on the
power unexpectedly, resulting in harmful or fatal
electrical shock.
NOTICE
Pump damage: Do not run the motor/pump assembly
dry for more than a few seconds. Running a pump that
is not completely lled with uid will cause damage to
the pump seal.
Proper heating operation: The high-limit temperature
control relays (TCR2, TCR4) must be set at least 18
°F (10 °C) higher than the corresponding control
temperature control relay for proper heating
operation. This will prevent nuisance tripping of
the high-limit circuit.
3.3.1 FIRST RUN PROCEDURE
1. Check and tighten all electrical and plumbing
connections.
2. Ensure isolation valves are open before energizing
the system.
3. Check the pump for proper rotation. NOTICE!
Do not run the motor/pump assembly dry for
more than a few seconds.
hFor three-phase heating systems, turn and
hold the on/off/prime switch to prime while
observing the rotation of the pump motor fan
at the rear of the motor. If the pump motor is
not rotating in the correct direction, switch any
two electrical leads at the main power terminal
block. See SECTION 2.6.2.Repeat this
procedure for both pump motors.
hSingle-phase systems are prewired to ensure the
pump motors rotate in the correct direction.
4. Bleed all trapped air from the heating system by
opening a plug or pipe tting at or near the pump.
Turn and hold the on/off/prime switch to prime
to evacuate any remaining air in the lines.
NOTE: When priming the pump, the pressure
gauge should indicate an increase in
pressure. Your system’s operating pressure
may vary depending on the conguration
of the engine.
5. Turn the on/off/prime switch to on to energize
the heating system.
6. Once operation is satisfactory, turn the control
dial on the temperature control relay TCR1 to the
desired temperature setting for engine coolant.
Turn the control dial on the temperature control
relay TCR3 to the desired temperature setting
for engine oil. Hotstart recommends a control
temperature on TCR1 of 122 °F (50 °C) and a
control temperature on TCR3 of 104 °F (40 °C). The
high-limit temperature setting on TCR2 and TCR4
should be set at 194 °F (90 °C). See SECTION
3.1.2 and SECTION 3.1.3.
OPEN
SCREW PORT
PRESSURE RELIEF
VALVE CAP
INSTALLED
SCREW
PUMP INLET PUMP OUTLET
Figure 11. DLV oil pump assembly. Note that the
pressure relief valve cap must always point toward
the inlet side of pump. Screw is installed on outlet
side of pump.

12 installation & operation manual | dlv heating system
4 MAINTENANCE,
REPAIR AND
TROUBLESHOOTING
4.1 SYSTEM FAULTS
4.1.1 COOLANT FAULTS
The coolant fault light will display if:
• The coolant pump motor protection switch is
tripped (MPS1).
• The coolant high-limit temperature is
exceeded (TCR2).
4.1.2 OIL FAULTS
The oil fault light will display if:
• The oil pump motor protection switch is
tripped (MPS2).
• The oil high-limit temperature is exceeded
(TCR4).
A failure in the pump motor that causes the motor
protection switch (MPS1 or MPS2) to trip will shut down
the corresponding heating system. A fault signal will
be transmitted and the coolant or oil fault light will
illuminate. If this failure occurs, the on/off/prime
switch must be switched to off and the operator must
press the MPS reset/on button to reset the fault. (See
SECTION 3.1.1.)
If there is a failure that causes a high temperature to
occur, the high-limit temperature controller (TCR2
or TCR4) will shut down the coolant or oil heating
system, including the pump motor. A fault signal will
be transmitted and the coolant or oil fault light will
illuminate. To restart the system, the on/off/prime
switch must be switched to off and then back to on
to resume operation once the uid temperature drops
below the high-limit preset (See SECTION 3.1.2.)
NOTE: A high-limit fault can only occur when the
respective heating element is energized. A fault
in one uid system will not cause the other uid
system to shut down.
For additional troubleshooting, see SECTION 4.5.
4.2 SYSTEM MAINTENANCE
WARNING
!
Hazardous voltage: Before wiring, servicing or cleaning
the heating system, turn off the power and follow your
organization’s lockout and tagout procedure. Failure
to do so could allow others to turn on the power
unexpectedly, resulting in harmful or fatal electrical
shock.
Instructions for the following maintenance procedures
are provided to ensure trouble-free operation of your
heating system. Replacement parts must meet or exceed
original part requirements in order to maintain the
compliance level of the original heating system.
NOTE: After maintenance is performed, refer
to SECTION 3.3.1 for system start-up
procedures.
4.2.1 PLUMBING CONNECTIONS
Periodically check plumbing connections for leaks and,
if necessary, tighten connections. A loose connection on
the suction side will cause a loss of flow and cavitation in
the pump. It can also pull air into the heating tank and
cause an element failure.
4.2.2 ELECTRICAL CONNECTIONS
Vibration may cause terminals to loosen. At start-up,
tighten electrical connections. Check connections
again in a week. Tighten all electrical connections every
three months.
4.2.3 SYSTEM MOUNTING
Vibration may cause mounting bolts to loosen.
Periodically check and tighten all mounting bolts.
4.2.4 MAGNETIC CONTACTORS
Magnetic contactors are used as voltage switching
controls for motors and heating elements in Hotstart
heating systems. The contactors use 120 volt or 240
volt coils. To test for failure, check for continuity across
the coil connections; an open or direct-short reading
indicates a failed contactor coil.
The contacts on the magnetic contactor should be
inspected periodically for welding, arc erosion and
mechanical wear. If any of these conditions exist,
replace the magnetic contactor. Hotstart recommends
contactors be replaced every five years.
4.2.5 PUMP SEAL
Pump mechanical seals are controlled leakage devices
and are not intended to create a zero leak seal. Some
leaking from the seal is expected during normal
operation. If seal becomes worn, replacement pump
seals are available. To ensure pump seal longevity,
ensure the supply lines do not restrict flow excessively
(see SECTION 2.1.1 and SECTION 2.4.1) and run the

13
installation & operation manual | dlv heating system
heating system for 20 minutes monthly during offseason
periods (see SECTION 4.4).
NOTE: Instructions to replace the pump seals are
included with replacement seals.
4.2.6 MOTOR LUBRICATION
Motors are installed with initial lubrication. If your motor
has provisions for relubrication, refer to the motor
manufacturer for recommended relubrication schedule
intervals. For recommended lubrication type, refer to the
motor nameplate.
NOTE: New motors installed on heating systems
placed in extended storage for a year or longer
may require relubrication. See SECTION 4.4.
4.2.7 OIL PRESSURE RELIEF VALVE
The oil pump pressure relief valve is internal to the pump
and releases pressure from the discharge side of the
pump to the suction side of the pump. No maintenance
for this part is required.
4.2.8 PRESSURE/TEMPERATURE
GAUGES
The pressure/temperature gauges will indicate a pressure
increase when the pump motor is engaged by turning
and holding the on/off/prime switch to prime or
during normal heater operation. The gauges will also
indicate the current temperature of the respective uid.
No maintenance for these parts are required.
4.2.9 VOLATILE CORROSION
INHIBITOR (VCI)
A volatile corrosion inhibitor (VCI) is provided with each
control box and should be replaced once a year.
NOTE: Heating systems placed in extended storage
will require that the VCI is replaced at six month
intervals. See SECTION 4.4.

14 installation & operation manual | dlv heating system
4.2.10 TEMPERATURE CONTROL RELAY
(TCR)
WARNING
!
Hazardous voltage: Before wiring, servicing or cleaning
the heating system, turn off the power and follow your
organization’s lockout and tagout procedure. Failure
to do so could allow others to turn on the power
unexpectedly, resulting in harmful or fatal electrical
shock.
If the DLV heating system does not maintain the desired
preset control temperature or signals a high-limit
temperature fault immediately upon system start-up,
the TCR (temperature control relay), the RTD (resistance
temperature device), or the RTD cable may require
replacement. To perform this troubleshooting, you
will need:
• Ohmmeter
1. De-energize the heating system. Verify uid
is present and ow is not restricted. Check
temperature gauge to ensure the liquid in the tank
is below 122 °F (50 °C).
2. Verify the control TCR is set correctly. Verify that
high-limit TCR is set at least 18 °F (10 °C) higher
than the control TCR set point.
3. Using the ohmmeter, measure the resistance
between TCR terminals T1 and T2. (See Figure 12.)
hIf the measured resistance is between 80 and
120 ohms continue troubleshooting. Proceed
to step 4.
hIf the resistance is lower than 80 ohms or
higher than 120 ohms,contact HOTSTART
for further assistance.
4. Using the ohmmeter, test for continuity between
TCR terminals T2 and T3:
hIf there is continuity between TCR terminals
T2 and T3, the TCR, RTD and RTD cable are
functioning correctly. Close control panel.
Allow uid to cool below high-limit preset
temperature. Perform system start-up (see
SECTION 3.3.1). If fault or temperature
problems persist after start-up, contact Hotstart
for further assistance.
hIf there is no continuity between TCR terminals
T2 and T3, locate connected RTD on the
heating tank. Unscrew the RTD plug from
RTD. See Table 2 and Figure 14, Figure 15. on
following page.
5. Using the ohmmeter, touch the probes to RTD
pin 1 and pin 3. See Figure 13.Note the resistance.
Touch the probes to RTD pin 1 and pin 4 to check
for continuity:
hIf the resistance between RTD pin 1 and
pin 3 is between 80 and 120 ohms and there
is continuity between RTD pin 1 and pin 4, the
RTD is functioning properly. Replace the
RTD cable.
hIf the resistance between RTD pin 1 and pin 3
is not between 80 and 120 ohms or there is
no continuity between pin 1 and pin 4, the
RTD is malfunctioning. Replace the RTD. See
SECTION 4.2.11.
PIN 1
(BROWN
WIRE)
PIN 3
(BLUE
WIRE)
PIN 4
(BLACK
WIRE)
K1
K3
TCR2 TCR4
K4 K2
TCR1 TCR3
HIGH LIMIT
OIL
HIGH LIMIT
COOLANT
CONTROL
OIL
CONTROL
COOLANT
K1
K3
TCR2 TCR4
K4 K2
TCR1 TCR3
HIGHLIMIT
OIL
HIGHLIMIT
COOLANT
CONTROL
OIL
CONTROL
COOLANT
Figure 12. Control TCRs (TCR1,
TCR3) showing terminals T1, T2
and T3.
Figure 13. RTD pins 1, 3 and 4. The resistance between pin 1 and
pin 3 should measure between 80 and 120 ohms. There should be
continuity between pin 1 and pin 4.
TCR TYPE RTD Position
TCR1 Coolant Control 50 °C Coolant Tank Inlet
TCR2 Coolant High-limit 90 °C Coolant Tank Outlet
TCR3 Oil Control 40 °C Oil Tank Inlet
TCR4 Oil High-limit 90 °C Oil Tank Outlet
Table 2. TCR types, default temperature settings and
corresponding RTD positions.