If you are reading this, then you are probably suffering from the very common E4 or E2 Error Code being displayed on your Corona (or Similar) Inverter Heater. The E4 Error Code is probably the most popular of the error codes which affect Inverter Heaters and this error can either be displayed from the moment the heater attempts to turn on, or it can occur intermittently, and sometimes the heater will work fine before eventually cutting out, with “E4” showing in the lcd display.
The Inverter Heater E4 Error code (and also E0 and E2) indicates either contaminated fuel or poor combustion, and is generally caused by failure to maintain the heater and its filters adequately, however on other occasions the E4 error occurs due to poor quality low grade fuel or water contamination within the fuel.
E4 Errors are more likely to occur if domestic heating oil kerosene is used in the Inverter Heater, due to the fact that domestic kerosene is stored in bulk for entire seasons in dirty underground tanks, however it can also occur in pre-packaged premium paraffin products, if the container has been stored in a cold location, exposed to air or has been stored for long periods and the fuel quality has degraded.
If your inverter heater is displaying the E4 error or the E0 or E2 Error codes, then you should do the following:-
1) Remove the fuel filter from inside the inverter heater, this is located in the bottom of the base, inside where the fuel storage tank sits, generally on all models its a small plastic mesh filter which just pulls out. Clean the mesh of the filter with clean Kerosene or Paraffin and scrub with an old toothbrush until its clean. DO NOT use water or any detergent.
2) Remove and clean the air filter located at the rear of the heater
3) Make sure that the fuel inside the tank is fresh. Fuel which has been stored inside the tank for several months, should be disposed off correctly, and the tank filled with new fuel. Always drain any used fuel from the heater tank into an airtight container, if the heater is to be unused for long periods.
4) Make sure that the heater is on a firm, level surface and that there is a reasonable space all around the heater. Ensure that the heater is the correct size for the room and that there is good natural ventilation present.
5) Buy a “Mr Funnel” filter, this is a special, re-usable funnel based filter which is designed to not only filter dirt from out of the fuel but will also remove all traces of water contamination which may have found its way into the fuel during storage or as the fuel ages. To filter the fuel, you simply pour the it from the original container into the heater tank using the funnel.
Using a Mr Funnel is a MUST if you choose to use domestic heating oil kerosene instead of premium fuel in an inverter heater on a regular basis, however it also prevents E4 errors from Pre-Packaged type premium fuels, especially if the containers are stored for long periods or in a cold location prone to condensation.
Following these basic steps will usually solve all, but the most stubborn E4 errors. However if you still get the same error after following the above advice, then you will probably need to clean out, and service the burner and combustion chamber inside your inverter heater. Check out our Servicing a Inverter Heater page for our step by step guide to cleaning and servicing these heaters, which includes pictures, and also a video detailing the procedure.
This information was taken directly from the user manual of a Corona Inverter Heater, as below.
The following image has been submitted to us by email from a blog visitor. The image clearly shows a large amount of carbon / rust / crud build up in the bowl under the heater combustion burner.
The sender assures us that this heater has been run on nothing but the recommended premium fuel. With this in mind, we now recommend filtering the fuel through a “Mr Funnel”, regardless of whether you chose to use the recommended premium fuel or standard Kerosene. We also recommend that this area of the burner is checked and cleaned out, during any routine servicing procedure. (Credit to “Mister B” for emailing us the image)