Hotstart DLV User manual

216306-000 rev0
INSTALLATION & OPERATION MANUAL
DUAL FLUID CIRCULATING HEATING SYSTEM
MODEL
DLV

i
installation & operation manual | dlv heating system
IOM216306-000
Corporate & Manufacturing
Headquarters
5723 E. Alki Ave.
Spokane, WA 99212 USA
509.536.8660
[email protected]
Oil & Gas Ofce
21732 Provincial Blvd.
Suite 170
Katy, TX 77450 USA
281.600.3700
[email protected]
Europe Ofce
HOTSTART GmbH
Am Turm 86
53721 Seigburg, Germany
+49.2241.12734.0
[email protected]
Asia Pacic Ofce
HOTSTART Asia Pacic Ltd.
2-27-15-4F Honkomagome
Bunkyo-ku, Tokyo
113-0021, Japan
+81.3.6902.0551
[email protected]
NOTE Typicalheatingsystemidenticationplate.Youridentication
platemayvary.
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. The system is pre-wired,
pre-plumbed and assembled on steel plate. Each heating system has an identication plate which includes
the part number and serial number.
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.

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.

iii
installation & operation manual | dlv heating system
TABLE OF CONTENTS
IDENTIFYING YOUR SYSTEM | I
WARRANTY INFORMATION | I
IMPORTANT SAFETY INFORMATION | II
1 OVERVIEW | 1
1.1 HEATING SYSTEM COMPONENTS | 1
1.2 OPERATION OVERVIEW | 2
2 PLUMBING INSTALLATION | 3
2.1 OIL PLUMBING INSTALLATION | 4
2.1.1 Oil Supply | 4
2.1.2 Oil Return | 4
2.2 OIL PLUMBING ILLUSTRATION | 5
2.3 COOLANT PLUMBING INSTALLATION | 6
2.3.1 Coolant Supply | 6
2.3.2 Coolant Return | 6
2.3.3 Coolant Pressure Relief | 6
2.4 COOLANT PLUMBING ILLUSTRATION | 7
2.5 MOUNTING | 8
2.5.1 Tank and Pump | 8
2.6 MAIN POWER SUPPLY | 9
2.7 CUSTOMER INTERFACE CONNECTIONS | 10
3 SYSTEM COMPONENTS AND OPERATION | 11
3.1 ON/OFF/PRIME SWITCH | 11
3.2 MOTOR PROTECTION SWITCH (MPS) | 11
3.3 PRESSURE/TEMPERATURE GAUGES | 12

iv installation & operation manual | dlv heating system
3.4 PRESSURE RELIEF VALVE | 12
3.5 HIGH-LIMIT TCR (TEMPERATURE CONTROL RELAY) | 12
3.6 CONTROL TCR (TEMPERATURE CONTROL RELAY) | 12
4 HEATING SYSTEM START-UP | 13
5 MAINTENANCE, REPAIR AND TROUBLESHOOTING | 14
5.1 COOLANT/OIL FAULTS | 14
5.2 SYSTEM MAINTENANCE | 14
5.2.1 Plumbing Connections | 14
5.2.2 Electrical Connections | 14
5.2.3 System Mounting | 15
5.2.4 Magnetic Contactors | 15
5.2.5 Pump Seal | 15
5.2.6 Motor Lubrication | 15
5.2.7 Coolant Pressure Relief Valve | 15
5.2.8 Oil Pressure Relief Valve | 15
5.2.9 Coolant & Oil Pressure/Temperature Gauges | 15
5.2.10 Volatile Corrosion Inhibitor (VCI) | 15
5.2.11 Temperature Control Relay (TCR) | 16
5.2.12 Resistance Temperature Device (RTD) | 17
5.2.13 Heating Tank/Element | 18
5.2.14 Reassembly of Heating Element and Tank | 18
5.3 RECOMMENDED MAINTENANCE | 20
5.4 STORAGE REQUIREMENTS | 20
5.5 TROUBLESHOOTING | 21
TABLE OF CONTENTS

1
installation & operation manual | dlv heating system
1 OVERVIEW
1.1 HEATING SYSTEM COMPONENTS
The DLV heating system consists of the following main components: See Fig. 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.
CHECK
VALVE
COOLANT
OUTLET
OIL
OUTLET
COOLANT
PRESSURE
RELIEF
VALVE
COOLANT
PRESSURE/
TEMPERATURE
GAUGE
OIL
INLET
COOLANT
INLET
IDENTIFICATION
PLATE
COOLANT
FAULT LIGHT
COOLANT
ON/OFF/PRIME
SWITCH
OIL
FAULT LIGHT
OIL
ON/OFF/PRIME
SWITCH
LIFT POINTS
OIL
PRESSURE/
TEMPERATURE
GAUGE
HIGH-LIMIT
RTD
(RESISTANCE
TEMPERATURE
DEVICE)
CONTROL
RTD
(RESISTANCE
TEMPERATURE
DEVICE)

2installation & operation manual | dlv heating system
1.2 OPERATION OVERVIEW
The DLV heating system is intended to maintain an engine’s optimal starting temperature while the
engine is shut down. The heating system may be activated locally or by optional remote control (see
SECTION 2.7). 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 1. 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.
COOLANT RETURN
OIL RETURN
OIL SUPPLY
COOLANT SUPPLY
PRESSURE RELIEF

3
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 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.

4installation & operation manual | dlv heating system
2.1 OIL PLUMBING INSTALLATION
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:
• Due to the increased viscosity of lubrication 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 sump, typically near or on the third
inspection cover. 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 customer-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 pump outlet. NOTICE! Do not reduce the return
line inner diameter.
• Install the oil discharge port near the engine oil pump (typically at the P-pipe before it enters the
main engine block) or to the opposite end of the oil sump.
Table 1. HOTSTART recommended hose inner diameters, line lengths and elbow counts for
DLV oil supply lines.
PUMP
INLET
HOSE INNER
DIAMETER MAX. LINE LENGTH MAX. ELBOW COUNT
1 inch NPT 1-1/2 inch 20 feet (6 meters) 4
1-1/2 inch NPT 2 inch 20 feet (6 meter) 4

5
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 SUPPLY
SECTION 2.1.1
OIL
DISCHARGE
PORT
SECTION 2.1.2
OIL SUCTION
PORT
SECTION
2.1.1
CHECK VALVE
SECTION 2.1.1
ISOLATION VALVE
ISOLATION VALVE

6installation & operation manual | dlv heating system
2.3 COOLANT PLUMBING INSTALLATION
2.3.1 COOLANT SUPPLY
When installing the DLV coolant supply line, refer to the following HOTSTART guidelines:
• 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.
• 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.
2.3.2 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.
2.3.3 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.

7
installation & operation manual | dlv heating system
2.4 COOLANT PLUMBING ILLUSTRATION
NOTE: Installation illustrations are for reference only and are not to scale. See part drawings for
dimensions and specications.
COOLANT
RETURN
SECTION 2.3.2
COOLANT
SUPPLY
SECTION 2.3.1
COOLANT
DISCHARGE
PORT
SECTION 2.3.2
PRESSURE RELIEF VALVE
SECTION 2.3.3
COOLANT
SUCTION
PORT
SECTION
2.3.1
ISOLATION VALVE
ISOLATION
VALVE

8installation & operation manual | dlv heating system
2.5 MOUNTING
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.
Overheating hazard: When mounting the heating tank, position the tanks so that they are completely full
of uid while in operation.
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.
2.5.1 TANK AND PUMP
Mount the heater in a vertical orientation with pumps directly below the control box.Reference drawings
for mounting position. When installing the heating system, note that the tanks requires a minimum of 30
inches (63.5 cm) of clearance to remove each element for maintenance. See SECTION 5.1.13.

9
installation & operation manual | dlv heating system
2.6 MAIN POWER SUPPLY
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.
1. Connect the specied power from the customer-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 Fig. 2.
2. Connect the main power ground wire to the ground lug or ground block on the electrical panel
located inside the electrical box.
Figure 2. The main
power supply terminal
blocks located in the
DLV control box.
Example shown is a
three-phase system.
Single phase terminal
blocks will be labeled
L1 and L2 or L and N.
The main power
ground wire must
be connected to the
ground lug or ground
block.

10 installation & operation manual | dlv heating system
2.7 CUSTOMER INTERFACE 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.
Reference electrical schematic drawing for proper wiring locations; the following illustrations are typical
customer interface locations. See Fig. 3 and Fig. 4.
The fault signal (coolant or oil) will indicate a heating system shutdown, triggered by either the high-limit
temperature control relay or the motor protection switch (see SECTION 5.1). The coolant pump motor
and oil pump motor indicate the respective uid system pump is running. When activated, the 24 V dc
shutdown connection shuts down the heating system. When deactivated, normal heating will resume. Use
this connection for remote operation of the heater when the on/off/prime switch is turned to on.
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.
1413
K2
1413
K4
K5
21 22
K6
21 22
K7
A1 A2
TB2:2
TB2:6
TB2:4
TB2:8
TB2:10
TB2:1
TB2:3
TB2:5
TB2:7
TB2:9
COOLANT FAULT, FAULT WHEN CLOSED
COOLANT PUMP MOTOR
OIL PUMP MOTOR
24VDC SHUTDOWN
OIL FAULT, FAULT WHEN CLOSED
TB2
135
2 4 6
7
8
9
10
Figure 3. Customer interface connection
wiring schematic for the DLV heating system.
Figure 4. Customer interface
connections (TB2) as shown in the DLV
control box.

11
installation & operation manual | dlv heating system
3 SYSTEM COMPONENTS AND OPERATION
The control box contains the electrical components for the heating system. The following is an operation
description for the standard parts located in the system, including:
• on/off/prime switch
• Motor protection switch (MPS)
• Pressure gauge
• Pressure relief valve
• Control TCR (temperature control relay)
• High-limit TCR (temperature control relay)
NOTE: Parts in the control box may vary depending on the particular system conguration purchased.
3.1 ON/OFF/PRIME SWITCH
• on – The system is on.
• off – The system is shut off.
• prime – Turn and hold the switch to prime to energize the pump motor in order to remove any air
in the respective uid system without energizing the elements.
3.2 MOTOR PROTECTION SWITCH (MPS)
The motor protection switch (MPS) protects the pump motor
from overloads. 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 5.1.
RESET / ON
STOP / OFF
Figure 5. Motor protection
switches MPS1 (coolant)
and MPS2 (oil). To reset
the MPS, the heating
system must be switched
off and the reset/on
button must be pressed.

12 installation & operation manual | dlv heating system
3.3 PRESSURE/TEMPERATURE GAUGES
The DLV model features a temperature/pressure gauge mounted at the inlet of each heating tank. The
gauges will indicate a pressure increase when the pump motor is engaged by holding the on/off/prime
switch to prime or during normal operation. The gauges will also indicate the current temperature of the
respective uid.
NOTE: Your system’s operating pressure may vary depending on the conguration of the engine.
3.4 PRESSURE RELIEF VALVE
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.
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.
3.5 HIGH-LIMIT TCR (TEMPERATURE CONTROL RELAY)
The high-limit TCR for each uid system
(TCR2 and TCR4) is a protection device to
prevent uid overheating. The high-limit TCR
uses a resistance temperature device (RTD)
located near the tank outlet. The default
setting for both high-limit TCRs is
194 °F (90 °C) and should always be at least
18 °F (10 °C) higher than the control TCR set
point. The high-limit TCR hysteresis is not used
in the high-limit control. See Fig. 6.
3.6 CONTROL TCR
(TEMPERATURE CONTROL RELAY)
The control TCRs are used to control the
temperature of the uid in each system. The
control TCR uses a resistance temperature
device (RTD) to sense the temperature of
the uid as it enters the heater. The standard
setting for the coolant control temperature
relay (TCR1) is 122 °F (50 °C). The standard
setting for the oil control temperature relay
(TCR3) is 104 °F (40 °C). See Fig. 6.
100
100 0
0
11 12 11 12
13 14 A2-13 14 A2-
A3
A1
A3
A1
T1 T2 T3T1 T2 T3
Figure 6. DLV system control TCRs and
high-limit TCRs. The standard setting for
coolant control TCR1 is 122 °F (50 °C); the
standard setting for oil control TCR3 is
104 °F (40 °C).
100
100 0
0
11 12 11 12
13 14 A2-13 14 A2-
A3
A1
A3
A1
T1 T2 T3T1 T2 T3
HIGH LIMIT
COOLANT
HIGH LIMIT
OIL
24

13
installation & operation manual | dlv heating system
4 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 relay (TCR2 and TCR4) must be set at least
18 °F (10 °C) higher than the corresponding control temperature control relay (TCR1 and TCR3) for proper
heating operation. This will prevent nuisance tripping of the high-limit circuit.
1. Check and tighten all electrical and plumbing connections.
2. Ensure isolation valves are open before energizing the system.
3. If you are operating a three-phase heating system, check for proper rotation of the pump motor.
Turn and hold the on/off/prime switch to prime to check the pump for proper rotation. NOTICE!
Do not run the motor/pump assembly dry for more than a few seconds. If the pump motor is not
rotating in the correct direction, switch any two electrical leads at the main power terminal block.
NOTE: Single-phase systems are prewired to ensure the pump motor rotates 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 dials on the temperature control relay TCR1 to the
desired temperature setting for engine coolant. HOTSTART recommends a control temperature on
TCR1 of 122 °F (50 °C). The high-limit temperature setting on TCR2 should be set at 194 °F (90 °C).
See SECTION 3.5 and SECTION 3.6.
7. Turn the control dials on the temperature control relay TCR3 to the desired temperature setting for
engine oil. HOTSTART recommends a control temperature on TCR3 of 104 °F (40 °C). The high-limit
temperature setting on TCR4 should be set at 194 °F (90 °C). See SECTION 3.5 and SECTION 3.6.

14 installation & operation manual | dlv heating system
5 MAINTENANCE, REPAIR AND TROUBLESHOOTING
5.1 COOLANT/OIL 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).
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 respective 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 3.2.)
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 3.5.)
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 5.5.
5.2 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 4 for system start-up procedures.
5.2.1 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.
5.2.2 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.