Generac Mobile MFH900 User manual

SAVE THIS MANUAL FOR FUTURE REFERENCE
MFH900
Flameless Air Heater
Owner’s Manual
For technical assistance contact:
www.generacmobileproducts.com
Technical Support
1-800-926-9768

Use this page to record important information about your unit
Record the information found on your unit data label on
this page. See Unit Serial Number Locations.
Engine and generator serial numbers are located on data
plates affixed to the engine and generator, respectively.
When contacting a Generac Mobile Authorized Service
Dealer (GMASD) about parts and service, always provide
the unit model and serial number.
Operation and Maintenance: Proper maintenance and
care of the unit ensures a minimum number of problems
and keeps operating expenses at a minimum. It is the
operator’s responsibility to perform all safety checks, to
verify that all maintenance for safe operation is per-
formed promptly, and to have the equipment checked
periodically by a GMASD. Normal maintenance, service,
and replacement of parts are the responsibility of the
owner/operator and, as such, are not considered defects
in materials or workmanship within the terms of the war-
ranty. Individual operating habits and usage may contrib-
ute to the need for additional maintenance or service.
Unit Model No.
Unit Serial No.
Engine Model No.
Engine Serial No.
Generator Model No.
Generator Serial No.
(000394)
WARNING
Breathing diesel engine exhaust exposes you
to chemicals known to the State of California
to cause cancer and birth defects or other
reproductive harm.
• Always start and operate the engine in a
well-ventilated area.
• If in an enclosed area, vent the exhaust to
the outside.
• Do not modify or tamper with the exhaust
system.
• Do not idle the engine except as necessary.
For more information go to
www.P65Warnings.ca.gov/diesel.
(000393a)
WARNING
CANCER AND REPRODUCTIVE HARM
www.P65Warnings.ca.gov.

Owner’s Manual for Flameless Air Heater iii
Table of Contents
Section 1: Introduction and Safety
Introduction ..................................................................1
Read This Manual Thoroughly ....................................1
Safety Rules .................................................................1
How to Obtain Service .................................................1
General Hazards ...........................................................2
Explosion and Fire Hazards ........................................2
Trailer Hazards .............................................................3
Battery Hazards ............................................................3
Service Safety ..............................................................3
Towing Safety ...............................................................3
Hitch and Coupling ......................................................4
Running Lights ............................................................4
Safe Towing Techniques .............................................4
Reporting Trailer Safety Defects ................................4
Section 2: General Information
Specifications ...............................................................5
Unit Dimensions ...........................................................6
Unit Serial Number Locations .....................................6
Component Locations .................................................7
Exterior ........................................................................7
Interior .........................................................................8
Control Panel ..............................................................10
Controller ....................................................................11
Controller Display: Alert (Icon) Definitions .................12
Controller Faceplate Icons ........................................13
Emissions Information ..............................................14
Engine Oil Recommendations ..................................14
Coolant Recommendation ........................................14
Fuel System ................................................................14
Hydraulic Oil ...............................................................15
Trailer Towing Guidelines .........................................15
Wheel Chock Guidelines ...........................................15
Rooftop Beacon .........................................................15
Home Page (Default Operator Display) ....................15
Controller Mode .........................................................16
Controller Monitoring, Diagnostic, and
Protective Features ....................................................17
Advanced Controller Functions .................................19
Section 3: Operation
Before Starting Engine ..............................................21
Pre-start Checklist .....................................................21
Engine Oil Check .......................................................21
Hydraulic Oil Check ...................................................21
Engine Coolant Check ...............................................21
Battery Check ............................................................21
Starting Engine and Heater .......................................22
Adjusting Air Output Temperature ...........................22
Adjusting Heater CFM ...............................................22
Changing Controller Mode ........................................23
Shutting Down Engine and Heater ...........................23
Emergency Stop Switch ............................................23
Battery Disconnect Switch ........................................23
Before Towing Unit ....................................................23
Section 4: Maintenance
Maintenance Tasks ....................................................25
Daily Walk Around Inspection ...................................25
Checking Engine Oil Level ........................................25
Draining Fluids—Union Fluid Drain ...........................26
Adding Coolant ..........................................................26
Removing Crankcase Filter .......................................27
Engine Diagnostic Port and ECM ..............................27
Maintenance Schedule ..............................................28
Engine Maintenance Schedule ..................................28
Hydraulic Oil Schedule ..............................................29
Hydraulic Oil Filters Schedule ...................................29
Accessing and Resetting Controller
Service Intervals ........................................................29
Other Maintenance Checks .......................................30
Section 5: Troubleshooting
General Troubleshooting Guide ...............................31
Controller Warnings and Faults ...............................34
Section 6: Wiring Diagrams
Main Control System .................................................37
Perkins Engine Aftertreatment .................................38
J1939 CAN Bus Network ...........................................39
Trailer Harness—Electric Brakes .............................40
Trailer Harness—Lights Only or With
Surge Brakes ..............................................................41
Hydraulic Circuit ........................................................43

iv Owner’s Manual for Flameless Air Heater
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Owner’s Manual for Flameless Air Heater 1
Section 1: Introduction and Safety
Introduction
Thank you for purchasing a Generac Mobile product.
This unit has been designed to provide high-perfor-
mance, efficient operation, and years of quality use when
maintained properly.
The MFH900 flameless air heater is designed and built
for sustained, reliable heat production in industrial oper-
ating conditions and environments. The MFH900 is built
to withstand frequent handling under these conditions.
The unit is mounted on a trailer that has forklift pockets,
tie-down points, and a central lifting point. The fully
enclosed design protects the operating components,
allowing all-weather storage and operations.
The information in this manual is accurate based on
products produced at the time of publication. The manu-
facturer reserves the right to make technical updates,
corrections, and product revisions at any time without
notice.
Read This Manual Thoroughly
If any section of the manual is not understood, contact
your nearest Generac Mobile Authorized Service Dealer
(GMP ASD), or contact Generac Mobile customer service
at 800-926-9768, or visit www.generacmobileprod-
ucts.com with any questions or concerns.
The owner is responsible for proper maintenance and
safe use of the equipment. The manufacturer strongly
recommends that if the operator is also the owner, to
read the owner’s manual and thoroughly understand all
instructions before using this equipment. The manufac-
turer also strongly recommends instructing other users to
properly start and operate the unit. This prepares them if
they need to operate the equipment in an emergency.
SAVE THESE INSTRUCTIONS for future reference. This
manual contains important instructions for the machine
that should be followed during installation, operation, and
maintenance of the heater and batteries. Always supply
this manual to any individual that will use this machine.
Safety Rules
The manufacturer cannot anticipate every possible cir-
cumstance that might involve a hazard. The alerts in this
manual, and on tags and decals affixed to the unit, are
not all inclusive. If using a procedure, work method, or
operating technique that the manufacturer does not spe-
cifically recommend, verify that it is safe for others and
does not render the equipment unsafe.
Throughout this publication, and on tags and decals
affixed to the unit, DANGER, WARNING, CAUTION, and
NOTE blocks are used to alert personnel to special
instructions about a particular operation that may be haz-
ardous if performed incorrectly or carelessly. Observe
them carefully. Alert definitions are as follows:
NOTE: Notes contain additional information important to
a procedure and will be found within the regular text of
this manual.
These safety alerts cannot eliminate the hazards that
they indicate. Common sense and strict compliance with
the special instructions while performing the action or
service are essential to preventing accidents.
How to Obtain Service
When the unit requires servicing or repairs, contact a
GMP ASD for assistance. Service technicians are fac-
tory-trained and are capable of handling all service
needs. For assistance locating a dealer, go to https://
www.generacmobileproducts.com/parts-service/find-
service.
When contacting a GMP ASD about parts and service,
always supply the complete model and serial number of
the unit as given on the data decal located on the unit.
Record the model and serial numbers in the spaces pro-
vided on the front cover of this manual.
(000100a)
WARNING
Consult Manual. Read and understand manual
completely before using product. Failure to
completely understand manual and product
could result in death or serious injury.
(000001)
DANGER
Indicates a hazardous situation which, if not avoided,
will result in death or serious injury.
(000002)
WARNING
Indicates a hazardous situation which, if not avoided,
could result in death or serious injury.
(000003)
CAUTION
Indicates a hazardous situation which, if not avoided,
could result in minor or moderate injury.

2Owner’s Manual for Flameless Air Heater
Introduction and Safety
General Hazards
Explosion and Fire Hazards
Asphyxiation. Running engines produce
carbon monoxide, a colorless, odorless,
poisonous gas. Carbon monoxide, if not
avoided, will result in death or serious injury.
(000103)
DANGER
Personal injury. Do not operate unit during transport.
Doing so could result in death, serious injury, or
property damage.
(000231a)
WARNING
(000111)
WARNING
Moving Parts. Keep clothing, hair, and
appendages away from moving parts. Failure
to do so could result in death or serious injury.
CAUTION
(000291)
Equipment damage. Do not attempt to start or operate
a unit in need of repair or scheduled maintenance.
Doing so could result in serious injury, death, or
equipment failure or damage.
WARNING
(000108)
WARNING
Hot Surfaces. When operating machine, do not
touch hot surfaces. Keep machine away from
combustibles during use. Hot surfaces could
result in severe burns or fire.
(000107)
WARNING
Hearing Loss. Hearing protection is
recommended when using this machine.
Failure to wear hearing protection could
result in permanant hearing loss.
CAUTION
(000229)
Equipment or property damage. Do not block air
intake or restrict proper air flow. Doing so could
result in unsafe operation or damage to unit.
CAUTION
(000240a)
Unit damage. Do not stop engine before heating
unit is cooled. Doing so could result in unit damage.
CAUTION
(000246b)
Equipment Damage. The emergency stop switch is
not to be used to power down the unit under normal
operating circumstances. Doing so could result in
equipment damage.
(000105)
DANGER
Explosion and Fire. Fuel and vapors are
extremely flammable and explosive. Add fuel
in a well ventilated area. Keep fire and spark
away. Failure to do so will result in death
or serious injury.
(000214)
DANGER
Explosion and Fire. Do not fill fuel tank past full line.
Allow for fuel expansion. Overfilling may cause fuel
to spill onto engine causing fire or explosion, which
will result in death or serious injury.
(000143)
DANGER
Explosion and Fire. Fuel and vapors are extremely
flammable and explosive. Store fuel in a well
ventilated area. Keep fire and spark away. Failure
to do so will result in death or serious injury.
(000147)
WARNING
Risk of Fire. Unit must be positioned in a
manner that prevents combustible material
accumulation underneath. Failure to do so
could result in death or serious injury.
WARNING
Fire risk. Fuel and vapors are extremely
flammable. Do not operate indoors. Doing so
could result in death, serious injury, or
property or equipment damage. (000281)
Explosion and fire risk. Do not smoke near unit.
Keep fire and spark away. Failure to do so could
result in death, serious injury, or property or
equipment damage. (000282)
WARNING

Owner’s Manual for Flameless Air Heater 3
Introduction and Safety
Trailer Hazards
Battery Hazards
Always recycle batteries in accordance with local laws
and regulations. Contact your local solid waste collection
site or recycling facility to obtain information on local
recycling processes. For more information on battery
recycling, visit the Battery Council International website
at: http://batterycouncil.org
Service Safety
•DO NOT perform even routine service (oil/filter
changes, cleaning, etc.) unless all electrical com-
ponents are shut down.
•Replace all missing and hard to read decals.
Decals provide important operating instructions
and warn of dangers and hazards.
Towing Safety
Towing a trailer requires care. The trailer and vehicle
must be in good condition and securely fastened to each
other to reduce the possibility of an accident. Some
states require that large trailers be registered and
licensed. Contact your local Department of Transporta-
tion (DOT) office to verify license requirements for your
particular unit.
WARNING
Personal injury. Trailer must be securely coupled to
the hitch with the chains correctly attached. Uncoupled
or unchained towing could result in death or serious
injury. (000233a)
(000234a)
WARNING
Crushing hazard. Verify unit is properly secured and
on level ground. An unsecured unit can suddenly roll
or move, causing death or serious injury.
WARNING
Property or Equipment Damage. Tighten wheel lug
nuts after first 50 miles to factory specifications.
Failure to do so could result in death, serious injury,
property or equipment damage. (000235)
WARNING
Rollover hazard. Unit must be placed on flat, level
ground to prevent tipping or rollover. Failure to do so
could result in death, serious injury, or property or
equipment damage. (000283)
WARNING
Property or equipment damage. Do not alter the trailer.
Alterations can damage essential safety items. Doing
so could result in death, serious injury, or property or
equipment damage. (000285)
(000162)
WARNING
Explosion. Do not dispose of batteries in a fire.
Batteries are explosive. Electrolyte solution can cause
burns and blindness. If electrolyte contacts skin or eyes,
flush with water and seek immediate medical attention.
(000163a)
WARNING
Risk of burn. Do not open or mutilate batteries.
Batteries contain electrolyte solution which can
cause burns and blindness. If electrolyte contacts
skin or eyes, flush with water and seek immediate
medical attention.
(000130)
WARNING
Accidental Start-up. Disconnect the negative battery
cable, then the positive battery cable when working
on unit. Failure to do so could result in death
or serious injury.
(000181)
WARNING
Vision Loss. Eye protection is required to avoid
spray from spark plug hole when cranking engine.
Failure to do so could result in vision loss.
WARNING
(000228)
Environmental Hazard. Always recycle batteries at an
official recycling center in accordance with all local
laws and regulations. Failure to do so could result in
environmental damage, death, or serious injury.
CAUTION
(000419)
Personal injury. Wear appropriate personal protective
equipment at all times while operating and servicing
unit. Failure to do so could result in personal injury.

4Owner’s Manual for Flameless Air Heater
Introduction and Safety
Hitch and Coupling
•Verify the hitch and coupling on the towing vehicle
are rated equal to, or greater than, the trailer’s
Gross Vehicle Weight Rating (GVWR).
•Verify the trailer hitch and the coupling are compat-
ible. Verify the coupling is securely fastened to the
vehicle.
•DO NOT tow the trailer using defective parts.
Inspect the hitch and coupling for wear or damage
before every tow.
•To eliminate squeaking, wipe the coupler clean and
apply fresh grease each time the trailer is towed.
•Connect safety chains in a crossing pattern under
the tongue.
•Before towing the trailer, verify that the weight of
the trailer is equal across all tires. On trailers with
adjustable height hitches, adjust the angle of the
trailer tongue to keep the trailer as level as possi-
ble.
•Verify all access doors on the trailer are closed and
locked.
Running Lights
•Verify directional and brake lights on trailer are
connected and working properly.
Safe Towing Techniques
•Practice turning, stopping, and backing up in an
area away from heavy traffic prior to transporting
the unit.
•Maximum recommended speed for highway towing
is 45 mph (72 km/h). Recommended off-road tow-
ing speed is 10 mph (16 km/h) or less, depending
on terrain.
•When towing, maintain extra space between vehi-
cles and avoid soft shoulders, curbs, and sudden
lane changes.
•Reduce speed before curves, and maintain speed
throughout the curve.
Reduce speed before going over bumps or holes. Keep
your foot off the accelerator while going over bumps or
holes.
Reporting Trailer Safety Defects
If you believe your trailer has a defect which could cause
a crash, injury, or death, you should immediately inform
the National Highway Traffic Safety Administration
(NHTSA) in addition to notifying Generac Mobile Prod-
ucts, LLC.
If NHTSA receives similar complaints, it may open an
investigation. If it finds that a safety defect exists in a
group of vehicles, it may order a recall and remedy cam-
paign. However, NHTSA cannot become involved in an
individual problem between you, your dealer, or Generac
Mobile Products, LLC.
To contact NHTSA, you may either call the Auto Safety
Hotline toll-free at 1-888-327-4236 (TTY:1-800-424-
9153), go to http://www.safercar.gov; or write to:
Administrator
NHTSA
1200 New Jersey Avenue S.E.
Washington, DC 20590
You can also obtain other information about motor vehi-
cle safety from http://www.safercar.gov.

Owner’s Manual for Flameless Air Heater 5
Section 2: General Information
Specifications
Description Unit of Measure MFH900
Engine
Make (Model) — Perkins (1204F-E44TTA)
EPA Certification tier 4 Final
Type — Diesel, liquid cooled, 4-stroke
Horsepower At Operating Speed hp (kW) 150 (112 kW)
Operating Speed rpm 2,200
Displacement in3 (L) 268.5 (4.4)
Cylinders qty 4
Fuel Type — #1 diesel (below 32 °F [0° C]), #2 diesel
Fuel Consumption gph (Lph) 4.9 (29.9)
DEF Consumption gph (Lph) 0.4 (1.51)
Fan — Puller type, 26 in (66 cm) diameter, seven blades, 26° pitch
Capacities
Minimum Run Time hr 26
Fuel—Tank, Usable gal (L) 200 (757.1), 178 (673.8)
DEF—Tank, Usable gal (L) 10 (38), 8 (30)
HTF—Tank, System gal (L) 14 (53), 20.6 (77.9 L)
Coolant gal (L) 4.8 (18)
Oil qt (L) 10.3 (9.75)
Heater
Type — Flameless, self-contained
Maximum Heat Produced BTU/hr (kW/hr) 875,000 (256.44)
Air Output—Temperature Range °F (°C) 120–180 (48.9–82.2)
Air Output—Volume ft3/min (m3/min) 3,500–5,000 (99.1–141.6)
Air Ducts qty, diameter Two, 12 in (30.5 cm)
Estimated Efficiency % 85
HTF Pump type Variable displacement piston pump
Trailer
Brakes Type Electric
Per-Axle Rating lb (kg) 8,000 (3,628.7)
Axles qty 1
Tire Size — ST215/75R15.7
Hitch size, type 2-5/16 in, ball coupler
Maximum Tire Pressure psi (kPa) 123 (848)
Electrical
System Voltage VDC 24
Battery—Voltage (Quantity Per Unit) VDC (qty) 12 (2)
Battery—Rating CCA 950
Battery—Group Number — 31
Controller, Display — Epec 3610, Wachendorf OPUS A3
Unit Weight
Dry lb (kg) 6,590 (2,992)
Operating lb (kg) 7,700 (3,512)
Specifications are subject to change without notice.

6Owner’s Manual for Flameless Air Heater
General Information
Unit Dimensions
Figure 2-1. MFH900
Unit Serial Number Locations
See Figure 2-2 for unit ID tag and Vehicle Identification
Number (VIN) tag. Important information, such as the unit
serial number, model number, VIN and tire loading
information are found on these tags. Record the
information from these tags so it is available if the tags
are lost or damaged. When ordering parts or requesting
assistance, you may be asked to provide this information.
Figure 2-2. Serial Number Locations
ABC
192 in (4.88 m) 94 in (2.39 m) 76.5 in (1.93 m)
B
AC
009912
Unit ID Tag
Inside unit, on engine mount
Serial Number
V
A
Model
KVA
Manufacturing Code
1 ph. 1.0PF 3 ph. .8PF 3 ph. 1.0PF
KW
Country of Origin
Weight (lbs/kg) RPM/Frequency
Rating
Ins. Class
FOR ELECTRICAL EQUIPMENT
ONLY.POUR MATERIAL
ELECTRIQUE SEULEMENT.
209649
Form: SFC626B
Manufactured by Generac Mobile Products, LLC.,
[phone] [phone]
VIN Tag
TIRE AND LOADING INFORMATION
RENSEIGNEMENTS SUR LES
PNEUS ET LE CHARGEMENT
SEE OWNER’S
MANUAL FOR
ADDITIONAL
INFORMATION
VOIR LE
MANUEL DE
L’USAGER
POUR
PLUS DE
RENSEIGNEMENTS
MANUFACTURED BY/FABRIQUE PAR: Generac Mobile Products LLC DATE: 00/0000
GVWR/PNBV: 000KG (0000LBS) COLD INF. PRESS./
PRESS.DE
V.I.N./N.I.V.:
00000000000000000
TYPE: TRAILER
MODEL: XXX000
GAWR / PNBE TIRE / PNEU RIM / JANTE GONF A FROID - KPA(PSI/LPC) SGL / DUAL
EACH
AXLE
THIS VEHICLE CONFORMS TOALL APPLICABLE STANDARDS PRESCRIBED UNDER THE U.S. FEDERAL MOTOR VEHICLE SAFETY STANDARDS(FMVSS)AND CANADIAN
MOTOR VEHICLE SAFETY REGULATIONSIN EFFECT ON THE DATE OF MANUFACTURE.
CE VEHICULE EST CONFORMEA TOUTES LES NORMES QUI LUI SONT APPLICABLES EN VERTU DU REGLEMENT SUR LASECURITE DES VEHICULES AUTOMOBILES DU CANADA EN VIGUEUR A LADATE SA
FABRICATION.
The weight of cargo should never exceed 0000KG (0000LBS)
Le poids du chargement ne doit jamais depasser 0000KG (0000LBS)

Owner’s Manual for Flameless Air Heater 7
General Information
Component Locations
Exterior
Figure 2-3. Exterior Components
A Roof beacon G Fuel fill
B Radiator fill access panel H Tie-down (4 locations)
C Air intake I Forklift pocket (4 locations)
D Exhaust J DEF fill
E Control panel K Battery for breakaway brakes
F Emergency stop switch L Union fluid drain port
M Hot air discharge ducts
A
G
D
F
H
J
K
I
L
M
B
C
E

8Owner’s Manual for Flameless Air Heater
General Information
Interior
Figure 2-4. Interior Components—1 of 2
A Engine crankcase filter L HTF ball valve
B Secondary fuel filter M Engine oil level gauge (dipstick)
C Primary fuel filter (water separator) N Engine oil filter
D Fuel lift pump O Engine oil ball valve
E Heat transfer fluid (HTF or hydraulic fluid)
reservoir
P Engine oil fill
F HTF fill point and breather Q DEF pump
G HTF level switch R DEF pump filter (under cap)
H HTF high-temperature switch S Coolant overflow tank
I HTF thermistor T Clog sensor for HTF filters
J HTF filter (2 locations) U Perkins ECU engine diagnostic port
K Inline fuel filter
000000
B
G
A
D
E
C
F
J
O
L
I
N
M
K
H
P
Q
R
S
T
U

Owner’s Manual for Flameless Air Heater 9
General Information
Figure 2-5. Interior Components—2 of 2
A Selective catalytic reduction (SCR) canister G Engine starter
B Intake air filter H Ground strip (on floor)
C Engine radiator I Fuse block (next to ground strip)
D Union drain manifold (through hole in floor)—ball
valves for DEF, coolant, and fuel
J Battery disconnect switch
E Positive air shutdown (PAS) K Hydraulic manifold (behind shield)
F Battery (2 locations) L Series turbocharger (behind shield)
000000
B
A
D
E
F
G
H
I
C
J
L
K

10 Owner’s Manual for Flameless Air Heater
General Information
Control Panel
Figure 2-6. Control Panel
AController
BUnit start switch
CMain power switch
DLight switch
EEmergency stop switch
FUSB port
E
C
A
B
D
F

Owner’s Manual for Flameless Air Heater 11
General Information
Controller
Figure 2-7. MFH900 Controller—Common Functions
AMain button (eight)
Eight buttons around the screen are for page-to-page navigation or real-time heater adjustment.
See Figure 2-8. On most pages, an icon displays next to each button (A). Each icon indicates
what navigation or adjustment occurs when the corresponding button is pushed.
Figure 2-8. Home Page
More information is provided throughout this manual.
BScreen
CFaceplate icon (four)
DKnob
Navigates selection on current page:
•Twist knob: Scroll
•Push knob: Select
EGo to Home page
F[not used’
GGo to previous page
D
E
F
G
AC
B
A

12 Owner’s Manual for Flameless Air Heater
General Information
Controller Display: Alert (Icon) Definitions
See Figure 2-9. The controller displays many alerts in
specific areas of the controller (A). Alerts are often
accompanied by explanatory text (B).
Figure 2-9. Alerts Display
Some alerts are routine and indicate normal unit function;
others indicate problems.
Routine Alerts
The alerts described below are routine and indicate
normal unit function.
Warning and Fault Alerts
When a warning or fault alert displays, the unit requires
inspection or service. See Troubleshooting for more
information.
AB
Icon Icon ID State Indicated Condition
Engine At Work Speed Steady ON (green) Engine is at desired work speed or higher (about 2,200
rpm or higher)
Engine At Idle Steady ON (green) Engine is at idle rpm (about 800 rpm or lower)
Wait to Start Steady ON Glow plugs are ON—engine is preheating
Engine Heating Steady ON (amber) Engine is heating coolant to a minimum temperature
Engine Cooling Steady ON (blue) Engine ECU indicates engine is cooling
Heater Cooling Steady ON During unit shutdown
Heater Heating Steady ON During unit shutdown
Wait To Disconnect Steady ON (amber) DEF purge cycle in progress (may take up to 10 minutes)
Corresponds with battery disconnect indicator light
Delayed Engine
Shutdown
Steady ON DPF outlet temperature is above a set temperature
threshold
Steady ON (amber)
and
Steady ON—Engine
Cooling lamp
Engine is cooling

Owner’s Manual for Flameless Air Heater 13
General Information
Controller Faceplate Icons
See Figure 2-6, Four icons are stamped into the
controller faceplate. They illuminate according to
situation.
Figure 2-10. Faceplate Icons
Icon (Lit) Indicates
Photo sensor for controller display (day or
night mode)
When lit (green), controller power is ON
When lit, USB cable is connected
[not used]
A

14 Owner’s Manual for Flameless Air Heater
General Information
Emissions Information
For emissions information, see the OEM engine manual.
Engine Oil Recommendations
Genuine Generac parts are recommended for all
maintenance items.
All Generac oil kits meet minimum American Petroleum
Institute (API) Service Class CJ-4/SM. Select the
appropriate viscosity oil grade according to the expected
operating temperature. Synthetic oil also can be used in
the appropriate weight as standard, once the engine has
been broken in. Once synthetic oil is used, it should be
used for the life of the unit. It is not recommended to go
back to a mineral oil. Do not use special additives.
See Specifications for engine oil capacity.
Figure 2-11. MFH900 Engine Oil Viscosity
NOTE: For temperatures below -4 °F (-20 °C), use SAE
5W-30.
For more information, see the engine manual.
Coolant Recommendation
Where the atmospheric temperature falls below freezing,
the cooling system should be drained after engine
operation. To eliminate the need for repeated draining
and refilling, the use of a 50/50 Ethylene glycol base
antifreeze/water mix is recommended. Never exceed a
60/40 antifreeze/water mix.
NOTE: Recommended coolant is ZEREX™ Nitrate Free
Extended Life Antifreeze/Coolant.
See Specifications for coolant capacity.
For more information, see the engine manual.
Fuel System
The heater is designed to operate with diesel fuel.
See Specifications for fuel tank capacity.
IMPORTANT NOTE: Comply with all laws regulating
the storage and handling of fuels.
Follow these guidelines:
•Use only ultra-low-sulfur diesel fuel.
•When temperatures are at or below freezing, use
No. 1D diesel fuel.
•When temperatures are above freezing, use No.
2D diesel fuel.
•In some areas of the country, climatized fuel—a
mixture of 1D and 2D, may also be used.
000000
(000149)
DANGER
Risk of poisoning. Do not use mouth to siphon
coolant. Doing so will result in death or serious
injury.
Freezing Point °F (°C) 3
(-16)
-13
(-25)
-31
(-35)
-58
(-50)
Coolant (% Volume) 30 40 50 60
Water (% Volume) 70 60 50 40
(000168)
DANGER
Explosion and Fire. Fuel and vapors are
extremely flammable and explosive. Keep fire
and spark away. Failure to do so will result
in death or serious injury.
(000204)
DANGER
Explosion and Fire. Do not overfill fuel tank.
Overfilling may cause fuel to leak and ignite
or explode, resulting in death or serious injury.

Owner’s Manual for Flameless Air Heater 15
General Information
Hydraulic Oil
NOTE: Sometimes referred to as heat transfer fluid or
HTF.
Type: Thrive DTE-10 ISO VG 68 hydraulic oil
See Specifications for tank and system capacities.
Trailer Towing Guidelines
Driving a vehicle with a trailer in tow is vastly different
than driving the same vehicle without a trailer in tow.
Consider the following:
•It takes longer to get up to speed.
•More room is needed to turn and pass.
•More distance is needed to stop.
•The driver is responsible for keeping the vehicle
and trailer in control.
Before towing, verify the following:
1. The coupling, safety chains, safety brake, tires,
wheels, and lights are in working order.
2. The breakaway battery is fully charged.
3. Wheel lug nuts are tightened to 85–95 ft-lbs (115–
129 Nm).
4. Brake controller engages the trailer brakes before
the tow vehicle brakes.
While towing, make regular stops to verify the following:
1. Coupler is secured to the hitch and locked.
2. Electrical connections are made.
3. Appropriate slack in the safety chains.
4. Appropriate slack in the breakaway switch pull-pin
cable.
5. Tires are inflated to proper air pressure and no
damage or unusual wear to tread or sidewalls.
6. Trailer and doors are secured and latched.
Wheel Chock Guidelines
•Select wheel chock according to equipment type
and size.
•Always use in pairs and on firm surfaces.
•Chock in direction of grade.
•Chock both sides of wheel if direction of grade is
unknown.
•Use wheel chock only after parking brake is
applied and tested.
•Center chocks squarely against tread of each
wheel.
•Do not drive over wheel chocks.
Rooftop Beacon
See Figure 2-3. The unit is equipped with a rooftop
beacon. The beacon indicates the following:
Home Page (Default Operator Display)
See Figure 2-13. The Home page is the default operator
display: Every time the unit fully starts without a
shutdown fault, the Home page displays.
Figure 2-12. Home Page
DANGER
(000239)
Hydraulic Fluid Injection. High-pressure, high-temperature
hydraulic fluid can pierce skin and cause severe burns. Do not
check for leaks with hands. Seek immediate medical attention in case of
accident. Failure to protect body accordingly will result in death or serious
injury.
WARNING
Personal injury. Trailer must be securely coupled to
the hitch with the chains correctly attached. Uncoupled
or unchained towing could result in death or serious
injury. (000233a
WARNING
Property or Equipment Damage. Tighten wheel lug
nuts after first 50 miles to factory specifications.
Failure to do so could result in death, serious injury,
property or equipment damage. (000235)
Beacon State Definition
Off Unit OFF or in forced shutdown due to
malfunction
Strobe Unit operational
Item Description
A Access Hydraulic System Information page
B Increase airflow CFM
C Decrease airflow CFM
(000234a)
WARNING
Crushing hazard. Verify unit is properly secured and
on level ground. An unsecured unit can suddenly roll
or move, causing death or serious injury.
A
B
C
D
G
F
E
H

16 Owner’s Manual for Flameless Air Heater
General Information
Accessing Home Page from Other Pages
When the Home icon displays (A), press corresponding
button once to display Home page.
Figure 2-13. Home Icon (A) Provides Access to Home
Page.
Controller Mode
The controller has two modes—AUTO and MANUAL.
•AUTO mode is for everyday unit operation, provid-
ing basic unit functions and access to related oper-
ational information.
•MANUAL mode provides advanced functions, and
is only accessible by keying a password.
NOTE: The unit starts in the mode in which it was last
shut down.
Changing Mode
1. See Figure 2-14. When the Mode icon displays
(A), press corresponding button once
Figure 2-14. Mode Icon (A)
See Figure 2-15. The Password Entry page displays.
Figure 2-15. Password Entry Page
2. Enter the password.
IMPORTANT NOTE: Contact Generac Mobile Techni-
cal Service for password.
About AUTO Mode
In AUTO Mode, three temperatures are available. At
each temperature, three airflow volumes are available.
See table below.
AUTO Mode Navigation
Figure 2-16. AUTO Mode Home Page
About MANUAL Mode
In MANUAL mode, temperature is adjustable by single
degrees (F) and blower speed is adjustable by single
CFM. See Specifications for ranges.
MANUAL mode provides advanced access to maintain,
diagnose, and troubleshoot the unit. A password is
required to access MANUAL mode.
D Access Engine & Fuel Information page
E Change mode
F Increase air-output temperature
G Decrease air-output temperature
H Access Engine Diagnostics page
A
A
Temperature—°F (°C) Airflow—CFM
Low 120 (48.9) Low: 4,630
Med: 4,770
High: 4,920
Med 150 (65.6) Low: 4,050
Med: 4,170
High: 4,280
High 180 (82.2) Low: 3,660
Med: 3,760
High: 3,860
Item Description
A Access Hydraulic System Information page
B Increase airflow volume
C Decrease airflow volume
D Access Engine & Fuel Information page
E Change mode
F Increase air-output temperature
G Decrease air-output temperature
H Access Engine Diagnostics page
A
B
C
D
G
F
E
H