Heater error codes

Heater errors.


As a prologue the vast majority of diesel heater issues are user error.



The most common codes are E08 and E10 (Catch all code for multiple failed starts)




These can be caused by multiple reasons.  E08 is lack of fuel.


  1. Is your tank above ¼ level (on level ground)?
  2. Have you been below ¼ since heater was last used?
  3. Is it over a month since you last used your heater?


If 1 or 2 applies, fill vehicle fuel tank and attempt to restart your heater 2/3 times in an attempt to draw fuel through. In some cases, it will not self-bleed. You will then need to manually bleed the air from the fuel system by following the manual pump procedure in your instruction book. (Copy available under support heading)


If 3 applies, you may have stale fuel within the fuel lines, and this will necessitate using manual pump procedure.  Heater may still not start if atomisation filter is clogged and a service will be required to resolve.




Low battery power can prevent your heater from starting. This is easily corrected if your vehicle is fitted with either a B2B charger or VSR (voltage sensitive relay/ split charge relay).


Start your vehicle engine, check your voltage on the heater controller, not anywhere else. Now start your heater watching this voltage. If it drops below 11.4v there is not enough power being delivered to your heater to allow a start.  Remedy – provide more power!  If power is not being delivered this would indicate either a B2B, VSR or Battery fault.




With the heater in off state, check your exhaust. Insert a finger into the exhaust ensuring you touch all sides. Remove your finger. If your finger is covered in black soot it is highly possible that the heater is 'coked' and will need to be serviced. This service is chargeable as proper use has not been adhered to.



E01 - Under voltage - your battery does not have enough power, please recharge.

E02 - Over voltage - Voltage is over the permitted level, reduce voltage to 12v.

E03 - Glow plug fault. Check leads and replace if necessary. Can be low voltage.

E04 - Fuel pump disconnected. Check lead to fuel pump, check connector is clicked in place. Can be low voltage.

E05 - Overheat. Check air intake is not restricted at rear of heater, check fan is not impeded. Ensure that the installed heat vent is not blocked / restricted. Also check that heating duct has not been crushed, thus  restricting air flow.  

E06 - Fan motor fault - Normally caused by low voltage.

E07 - Communication between controller and heater broken, check lead and connection plug. Again can be low voltage.

E08 - Low fuel or air in fuel lines - refuel vehicle, check fuel filter is full if fitted. Can be low voltage.

E10 - One or more of the above error codes and the unit has been restarted a number of times without success.

Most errors can be self cleared by using the above  table of codes. E08 lack of fuel may need to be restarted a number of times to refill fuel lines.  After a few failed attempts the heater should ignite and clear errors. Callouts for no fuel will be chargeable. The unit may smoke when started, this is normal and will clear. Do not turn off until it does.

But I haven’t run out of diesel?

On installation the fuel stand pipe inserted in to your tank is placed approx at 1/4 tank level to ensure heater does not drain your tank. If you allow your fuel to drop below a 1/4 tank it is possible that the fuel lines and fuel filter may back syphon in to the tank as it is below the level of the standpipe. To eradicate this, do not allow your tank to go below 1/4 full. Thus you can run out of fuel without actually being aware that you have.


 If after checking the above tables you cannot get your heater to start, please click the help button below to request support by raising a support ticket fully detailing your fault or if during office hours, call us on 01555 728515.