Maxi Heat 500IQ
SERIAL NUMBER 14-000001 AND UP
MH500 IQ Specs
● Btu per burner- 515,000
● CFM per burner- 3200
● Fuel consumption per burner- 3.65 Gal/h
● Recommended fuel consumption- K-1 Kerosene or No.1 Diesel
● Operating power per burner- ~115 V, 1-PH, 60Hz 24 A (MAX 82 A)
● Weight per burner- 357 lbs
● Nozzles per burner- 2 GPH 60` Delavan Type A & 1 GPH 60` Delavan Type W
● Operating fuel pressure- 145 PSI/ 1000 kpa/ 10 bar
Overview
The IQ system is a design that allows for the simplicity and ease of
operation. At start up the IQ system will calibrate for the ambient air
temperature and elevation to determine the air to fuel ratio setting for the
air band. There are no more calibrations needed after this point and the IQ
system will recalculate the airband adjustment as ambient temperature
changes.
Control Screen Flickering/ Turning off & On
❏ The screen is a 12 volt system and receives power from the transformer box next
to the IQ controller. Check power at the two terminal wires (blk & white) going
into the right side of the IQ control. Check all connections on the main PC board
and fuses.
❏ Check the Voltage regulator in the control box below Image (A). Make sure all
voltage is proper.
❏ Make sure the rocker switch on the heater outlet door is working (Picture below).
The switch is a two pole switch that closes once the door is opened. Power is
sent to the screen for illumination.
Maxi Heat 500IQ
SERIAL NUMBER 14-000001 AND UP
❏
❏
❏ If the problem persists and power at the converter box showing 12 volts to the
screen, then replace the screen.
Maxi Heat 500IQ
SERIAL NUMBER 14-000001 AND UP
Engine Does Not Run
**
Maxi Heat 500IQ will not start ( The engine will crank over ,but not run) Isuzu Genset
Note
: If the unit has a shocker valve, check the value and make sure the shocker is open.**
❏ Ensure the unit has enough fuel.
❏ Go through and check all the connections and most importantly check the
emergency shutdown connection to make sure the connection is secure.(Isuzu
Engine Timer Module-921432/ Cat C1.5 T4F- 650302)
❏ If all connections are secure then check to see if the engine is getting fuel.
❏ Pull the return line on the fuel pump and turn the engine over to see if the fuel
pump is working correctly. Loosen the injector line at the injector to see if there is
further fuel flow.
❏ The unit is getting fuel and the Fuel pump is working, find the fuel solenoid on the
engine. Check the fuel shut off solenoid to ensure plunger retracts (example “A”,
solenoid plunger retracts from voltage on hold wire)
❏ If the pump works when an auxiliary power source is applied then trace through
wiring for loss of voltage. Power is pulled from the engine starter and goes
through the temp and oil pressure switches. Check schematic for further testing.
Maxi Heat 500IQ
SERIAL NUMBER 14-000001 AND UP
❏
Maxi Heat 500IQ
SERIAL NUMBER 14-000001 AND UP
Burner Cycles On & Off
**Maxi Heat 500IQ has one burner that will begin to run and then shuts down for High Temp
Fault. ( Message appears on the IQ screen).**
❏ Each burner or both cycling on and off indicates that there is a possibility of
backpressure. Back pressure occurs when the flow of heat is restricted and not
moved which accumulates at the outlet or in the burner itself. Kinks in the ducting
can cause this issue. Make sure the ducting is straight with limited bends and no
elevated lifts or descending of the ducting.
❏ Check ducting for proper flow.
❏ Ensure the high limit sensor is working at the end of the outlet.
❏ Check the main blower fans connection and ensure it is turning on as needed.
Faulty connections or loss of power can cause a stall in fan operation which in
turn causes the heater to increase temperature.
❏ Make sure heat going into the area is ventilated so heat does not accumulate
and raises temperature to increase output.
Maxi Heat 500IQ
SERIAL NUMBER 14-000001 AND UP
Blower Fan Stops Circulating or gets a Red “X” over fan:
**MH 500 IQ has a burner that will start up and the fan will not turn on. Fan not running
will cause the unit to shut down
.**
❏ When this fault occurs it is an indication the fan is losing power.
❏ Check all the circuits to the fan. Power comes from 120 plug in into the bottom of
the IQ controller.
❏ Start with going to the IQ control box for the burner that is having the issue. Open
the cover of the box and over to the side is a wrench icon, press it. After pressing
the icon type the password 123 then press the Enter button. You can control the
fan manually from this point.
❏ Note: If you turn the fan on manually and the fan doesn't run, then the
motor for the fan could be faulty and need to be replaced (#107194)
❏ If the fan runs while in manual mode then the fan is working and power going to
fan is ok. The circuit into the IQ controller that controls the blower fan has a loose
or faulty connection.
❏ Check the red terminal block at the bottom of the IQ controller (See examples
below). 120 volts into the terminal block feeds the relay above it and into the fan
circuit during the purge process.
Maxi Heat 500IQ
SERIAL NUMBER 14-000001 AND UP
Maxi Heat 500IQ
SERIAL NUMBER 14-000001 AND UP
Maxi Heat 500IQ
SERIAL NUMBER 14-000001 AND UP
No Power To IQ Control
**Maxi Heat 500IQ Controller does not turn on or has no power to the IQ box.**
❏ No power into the IQ controller will not activate the LCD screen for further
operation. Make sure the door on the outlet (heat out of burner) side is
open. The micro switch in the corner of the door activates power to each
screen. * Switch is a two pole switch, if one side fails then the other could
still open and provide power to the other screen.*
❏ Check the relay in the transformer box next to the controller (Example
“A”). Make sure connections are secure and the relay is functioning
properly.
❏ Check the heater element on top of the fuel water separator filter. If
element shorts then it will draw too much amperage and not allow the
screen to power up.
❏ If the IQ controller has 12 volts on the two wire ( example “B” below)
harnesses into the side of the controller. If the wire has 12 volts then the
screen needs to be replaced.
❏ Example “A
”
Example “B”
Maxi Heat 500IQ
SERIAL NUMBER 14-000001 AND UP
❏
Maxi Heat 500IQ
SERIAL NUMBER 14-000001 AND UP
Burner shuts off for “Burner Power Break” or will not turn on
**Burner shuts off or always seeing “Burner Power Break “ fault on screen.**
❏ During the purge cycle at the initial start up the burner ignitor box receives
all its power from the IQ controller. System is 120 volts and is used to
power the burner and fuel system.
❏ “Power Break” refers to the break in power to the burner. Test for loss of
voltage at the Ignitor box in the burner assembly. (See example “B”)
❏ Terminal “N” & “L” are power in. If there is no voltage then check the IQ
controller for power loss. Power into the controller red terminal block
distributes voltage to the fan and burner.
❏ Check the red terminal block for power in and out (120 v). Make sure
connections are secure.
❏ Check the 15 amp fuse on the left of the controller. (Example “C”). If it
fails, replace it.
❏ Test for voltage into the power relay above the red terminal block. During
purge power goes to relay and out into the thermal breaker. (Example
“C”). If failed, replace it.
Maxi Heat 500IQ
SERIAL NUMBER 14-000001 AND UP
❏
Example “B
”
Maxi Heat 500IQ
SERIAL NUMBER 14-000001 AND UP
Maxi Heat 500IQ
SERIAL NUMBER 14-000001 AND UP
Maxi Heat 500IQ
SERIAL NUMBER 14-000001 AND UP
Reset Safety Thermostat fault:
**Safety thermostat is a protection for the high limit. If the fan has failed or heater shut down
incorrectly it creates trapped heat which trips the thermostat.**
❏ Look for the black cap on the heat exchanger below the main blower fan.
(Example “A”)
❏ Remove the cap and you will expose a red button. This button is
connected to the safety thermostat and has to be reset. Push and hold for
five seconds.
❏ If the thermostat continues to trip then give it 5 to 10 minutes for the heat
to dissipate.
❏ If the problem persists then replace the safety thermostat.
❏
Maxi Heat 500IQ
SERIAL NUMBER 14-000001 AND UP
Burner starts to smoke and build black smoke out of exhaust stack:
** Black smoke is an indication the unit is not getting enough air, bad fuel or carbon build up in
the chamber.**
❏ Make sure air setting is on a specified number that the IQ controller
recommends at the time of start up. DO NOT adjust air setting during
operation unless the IQ controller specifies. (Any change of ambient
temperature and elevation requires smaller or higher amounts of air
mixture.)
❏ Check for any debris or material covering or blocking the air damper.
Clean and clear.
❏ Check fuel pressure and maintain 140-145 PSI at the pump.
❏ Ensure fuel nozzle NO 1 & NO 2 are both clean and working correctly.
Check the schematic for a list of wiring for each nozzle. IQ logic controls
both nozzles to maintain temperature.
❏ Make sure the heat exchanger and burn chamber are clear of any soot
build up. If there is a large amount of build up then take the burner apart
and wash with hot water high pressure hose. Let the barrel air dry before
using.
❏ Make sure only NO 1 Diesel fuel is used. Any additives can cause more
gel-like substances which will create fuel issues.
Maxi Heat 500IQ
SERIAL NUMBER 14-000001 AND UP
Filters perengine option:
Oil Change Intervals:
Caterpillar C1.5- Every 500 hours
Isuzu 3CE1- Every 500 hours
MH 500IQ MCS W/ ISUZU T4F 3CE1
Burner
FUEL FILTER (35
MICRON)
107222
****MH**\ 14-******
Engine
AIR FILTER
650290
****MH**\ 14-******
OIL FILTER
22-000309
****MH**\ 14-******
FUEL FILTER
22-000310
****MH**\ 14-******
FILTER KIT (ALL
FILTERS)
108461
****MH**\ 14-******
MH 500IQ MCS W/ CAT 1.5 NA T4F
FUEL FILTER (35
MICRON )
107222
****MH**\ 14-******
Engine
AIR FILTER
102580
****MH**\ 14-******
OIL FILTER
650304
****MH**\ 14-******
FUEL FILTER
103155
****MH**\ 14-******
FILTER KIT (ALL
FILTERS)
108464
****MH**\ 14-******
Maxi Heat 500IQ
SERIAL NUMBER 14-000001 AND UP
Isuzu T4F 3CE1 Parts:
● Dipstick Tube EXT Assy- ( 100604 )
● Starter-102465
● AVR Board-103016
● Stop Solenoid--22-000316
● Stop Solenoid O Ring- 22-000329
● Alternator Diode- 22-000324
● Temp Switch- 22-000325
● Oil Pressure Switch- 22-000326
● Relay Assembly- 650423
● Fuel Pump- 22-000317
● Auto Shutdown Timer-921432
● Filter Kit (Air Fuel & Oil)- 108959
● Fuel Water Separator ( 35 Micron Fuel Filter)- 107222
● Timer Module-921432
Cat 1.5 T4F Parts:
● Ignition Keys- 920474
● Ignition/Cat- 920475
● Hour Meter- 340014
● Timer/Shutdown- 650302
● Cat 1.5 Muffler-104867
● Muffler Gasket- 650234
● 3 way Fuel Gauge- 103205
● Filter Kit (Air Fuel & Oil)- 108961
● Fuel Water Separator ( 35 Micron Fuel Filter)- 107222
● Timer Shutdown-650302
*Check engine operators manual for specific recommended lubricants.
*Additional warranty information & claim forms can be obtained on Allmand.com.
*Please contact Allmand Tech line for additional help and troubleshooting @ (308)
995-3431 / Parts (800) 562-1373.
Maxi Heat 500IQ
SERIAL NUMBER 14-000001 AND UP
