When the heater attempts to light, there is no flame and a flame-out occurs after a few seconds.

Press the reset button on the heater and look through the flame observation window and check for a glow when the ignitor LED on the heater is ON. To get the best viewing angle, look through the window from the right side. The burner tube and the ignitor are located towards the left of the observation window. The glow of the ignitor should be visible through the holes in the burner tube. On a bright day, it may be necessary to block out the light to get a good view.

The heater has flamed out, but I was not there when it happened. The flame outs are not frequent enough for me to be there when they happen.

  1. This is a difficult problem to diagnose. The problem could be within the heater, or it could have something to do with the fuel system leading up to the heater. To determine which of these is the problem, the heater should be run from a separate fuel can.
  2. Clamp off and disconnect the fuel return line.
  3. Connect a 3 foot piece of 1/4″ fuel line (or 1/4″ clear hose to get more information) to the fuel return fitting on the heater. Place the end of this fuel line into a fuel container.
  4. Clamp off and disconnect the fuel line going to the fuel inlet of the heater.
  5. Connect a 3 foot 1/4″ fuel line (or 1/4″ clear hose to get more information) to the fuel inlet fitting on the heater and place the other end in the fuel container. Make sure there is enough fuel in the fuel container so the end of the hose is submerged in fuel.
  6. The fuel in the fuel container should be completely clean, or an in-line fuel filter should be placed on the end of the 3 foot fuel line that is placed in the fuel container. If any debris is drawn into the fuel line, it will lead to additional problems.
  7. Press the reset button on the front of the heater and allow the burner to fire and run long enough to determine if it is going to flame out. You may need to run the heater off the fuel can for more than a day, so make sure you use at least a 5 gallon fuel can and keep the fuel level above the 1/4 mark.

The burner fires, but the flame sputters and eventually goes out.

The sputtering effect is due to air in the fuel system. When the burner chamber is hot, this sputtering effect can cause the heater to backfire. Sputtering is commonly caused by leaks in the fuel line, a damaged O-ring in the fuel nozzle, or a damaged distributor in the fuel nozzle. The most common problem is damage to the fuel nozzle.

  1. Service the fuel nozzle and inspect the O-ring and the distributor/stem in the fuel nozzle for damage. If the O-ring is damaged, replace it. If the distributor and/or stem are damaged, replace the entire nozzle.
  2. CAUTION: Make sure the burner box cover is secured to the burner box before attempting to start the heater. If the heater were to attempt to fire with the burner box cover off, it could project open flame towards the user.
  3. Once the fuel nozzle has been repaired/replaced/cleaned, press the power button on the front panel of the heater and attempt to run the heater.

The burner fires with a stable flame, but the flame goes out after a while and a flame fault is indicated. This happens frequently enough that I’m able to observe the heater when the flame goes out.

  1. Press the reset button, observe the flame, listen to the burner components (air compressor is the loudest), and wait for the flame to go out. Observe the delay (if any) between the time the flame goes out and the time the air compressor stops running. The difference you’re looking for is between absolutely no delay (0 seconds), or a delay of anything over 1 second.
  2. An alternative to this test is to have someone in front of the heater and someone at the heater exhaust. Press the reset button, observe the flame, observe the exhaust, and wait for the flame to go out.

Flame Fault

Notes:

  • For troubleshooting a flame fault, leave the burner switch on the Remote Operating Panel in the ON Position.
  • There are three methods to reset the burner after a flame fault has been detected:
    1. Turn the burner switch OFF, wait 1 second and turn it ON again.
    2. Press the reset button on the front panel of the heater (this method will be used in this troubleshooting section).
    3. On the touchscreen remote, press the “reset” button.

Check the following before continuing with the troubleshooting:

  • The fuel supply from the fuel storage tank to the fuel inlet of the heater must be from a dedicated fuel pickup on the top of the tank.
  • The fuel level in the fuel storage tank must be above the level of the bottom of the fuel pickup tube. In most cases, the fuel pickup tube in the fuel tank does not go all the way to the bottom. It is usually installed somewhere between the one quarter and half way mark on the fuel tank. This is done so the heater does not drain the fuel in the tank and leave the user stranded.
  • The total rise from the bottom of the fuel pickup tube to the fuel inlet on the heater should not exceed 60”.
  • The fuel return from the heater must go back to the diesel fuel storage tank.
  • The fuel line from the diesel fuel tank to the inlet of the heater must not have any kinks or leaks.
  • All fittings must be leak free.
  • The external fuel filter must be clear of any contaminants obstructing the flow of fuel.
  • The first time that the fuel line is connected to the heater, there will be air in the line. It may be necessary to reset the heater a couple of times to bleed the air from the fuel line. It is strongly recommended that the external fuel filter bowl be filled with fuel prior to attempting to start the heater for the first time.

If any of the above issues were found to be a problem, correct the situation and press the reset button on the front panel of the heater to allow the burner to fire again.

Keeping the power button ON, remove the screws on the front panel of the heater and fold down the front panel (do not disconnect the plug on the front panel). IMPORTANT: when folding down the front panel, place a rag underneath the wires to prevent them from getting cut on the edge of the bottom tray. Also, use spacers underneath the panel which will prevent the buttons from being pressed.

CAUTION: If the use of the bypass mode is required during troubleshooting, it’s strongly recommended to disconnect power to the air compressor prior to going into bypass mode. Do this by disconnecting the RED power wire to the air compressor from the main harness. The power and ground wires for the air compressor are paired together using RED heat shrink for easy identification.

  • With the power to the air compressor disconnected, no fuel will be delivered into the burner chamber, so it is safe to run the heater in bypass mode.
  • If the air compressor is connected, then the heater will attempt to deliver fuel into the chamber, even if ignition does not occur and the flame sensor indicates a flame fault. If this happens, press the power button right away to get out of bypass mode and power down the heater.
  • If it’s necessary to keep the air compressor connected while in bypass mode, make sure the coolant temperature is low. If the heater fires and continues to run, even though the operating limit has been reached, the safety limit sensor will shut the heater down. As good practice, it’s best not to run the heater in bypass mode while the coolant is hot.
  • If the remote switch is left in the ON position during troubleshooting, pressing the reset button to get out of bypass mode will put the heater back into a state where it will attempt to fire as long as the coolant has not reached maximum operating temperature. If you have finished with your test in bypass mode, pressing the power button instead of the rest button will power down the system and will prevent a further attempt at starting the heater.