Corona Inverter Heater E1 Error

If you are reading this, then the chances are that you are researching for information in respect of your Corona Inverter Heater constantly giving an E1 error code and refusing to ignite, there is a lot of information and discussion about the E1 errors on the internet, and many heater owners seem to suffer from it, however there hasn’t been a workable solution provided, until now.

If you read the manual, then very little user advice is provided other than that the E1 Error code is diagnosed as an Electrical Error, which requires further investigation by a Corona service agent, which can work out expensive, however I manage to diagnose and correct the Corona E1 Error myself for no cost, and this is the information which I am going to share with you here.

If your Corona Inverter Heater is displaying E1 on its display panel, then check to ensure that the following symptoms are also present.

The heater switches on as normal, displaying the current room temperature and desired temperature, you start the heater and it goes through its usual preheat procedure, including the faint whirring from the internal combustion fan.

Then, at the point where you would normally hear the pulsing from the internal pump, and the heater starting its ignitor, the heater cuts out, and ‘E1’ is shown in the display.

Occasionally, the inverter heater may also just display Error E1 right from the start, especially if several constant previous attempts have been made to reset and restart the heater.

So, if your Corona inverter heater symptoms sound just like mine above, then read on and i’ll tell you how to correct and remove the error,  and restore your heater to fully working condition, without the time and expense of sending it to a Corona heater service agent.

Because the E1 error is experienced when the heater would normally pulse its internal pump, sending fuel to the atomizing chamber, then it is easy to believe that the E1 code represents a faulty fuel pump, and I very nearly fell into the trap of ordering a brand new pump. However when I removed the pump and connected it to a 24v dc supply, it worked just fine, so back into the heater it went and I began to look elsewhere.

I then turned my attention to the various sensors inside the heater. On the circuit board, I read the various connector designators and noticed that the heater contained a “Flame Rod”. These are small metal sensors, which are also used in gas furnaces and stoves. A flame rod is designed to sit in the path of the flame just above the burner, and when heated they change in resistance value, telling the electronic control system that the flame has successfully ignited and is present.

The flame rod serves two important roles, first of all, it tells the Electronic system that the burner has successfully ignited, and so switches off the ignition system, and secondly if the flame goes out, such as in a fault condition, then the system can detect the flame loss and switch off the heater and fuel supply for safety reasons.

Because the flame rod, works entirely on changes in its resistance value being detected, then any small change outside of the normal parameters can cause false readings and incorrect operation of the electronics. These small changes can be caused by a build up of carbon or any other contaminates found inside a heating chamber. So, this was immediately the next prime suspect in my fault finding.

The Flame Rod, is located inside the Burner (atomisation) chamber, deep inside the heater, and so it requires the heater to be stripped down. This isn’t as bad as it sounds, because you can take the opportunity of cleaning out the chamber, and generally serving your Corona Heater at the same time.

Taking apart the heater isn’t as scarey as it sounds, and can be done by most competent people in around 45 minutes with only a little a care and some basic tools.

The procedure for dis-assembling and servicing a Corona Inverter Heater can be found here

Once inside the atomisation chamber, you will see two metal rods close to the burner, one is supplied with a thick cable leading to a small plastic box – this is the ignitor. The other rod, at the opposite side is fed by a small single wire (on my heater it was a yellow wire), and held in place by a single screw. This is the Flame Rod, and to remove it, all you need to do is to gently slide off the connector terminal, and undo the screw holding of the bracket holding it in place.

Once removed from the heater, you will probably notice a black build up of carbon on the rod, this needs to be removed and cleaned as well as possible. First of all I washed the rod in standard dish detergent, followed by a blast of oven cleaner and an old toothbrush (in the UK I used Mr Muscle oven cleaner). Wear gloves if you use oven cleaner as its nasty stuff.

Next, I gently sanded the metal rod with very fine grit sandpaper. The key here is to sand it gently (we aren’t sanding down an old Toyota!), all you are looking to do is to clean off the black deposits. If you have some wire wool, this would be even better.

Once this was done, I made sure that the flame rod was fully dry, before refitted it and putting the inverter heater back together again. Once re-assembled, the heater fired up as normal and voila! – problem solved, and one working heater.

Of course depending on the age of your inverter heater, and the wear on the flame rod, cleaning it may only be a temporary fix, and so it might be wise to contact a parts distributor and buy a replacement flame rod, ready to replace it, should the E1 error return at a later time.

Update:- If you experience persistent errors even after cleaning the flame rod, and are unable to easily find a replacement, you could try the following workaround, shown in the video below.

And that  (in the majority of cases) , is how you solve the Corona Inverter Heater E1 Error.