first of all - sorry for the english language, but I think it is better than google translate

I am maybe the forst owner of CTC Miljo 1100 in Bulgaria (bought it in 1994) and it still operates great on electricity only till this day.
My problem is not connected to pellets, but I could not find information about this device anywhere in internet, but some comments here, so I hope someone might be able to help me. The company which I bout if from, does not exist already, so i cannot find help in my country.
The problem is that sometimes the boiler does not want to engage the 9 kw heater and only operates at 2.25 + 4.5 kw. This usually happens after power faliture. Yesterday one of my fuses burned out, and when I changed it and turned the boiler ON, it engaged p to 6.75 kw only even though the water is cool and the central knob is turnet to max. I do not have user manual, so I am not sure what to do.
A little to the right of the electric heaters knob (in the center) there is a hole and a small light turns on and off. I am sure it might be some kind of warning light but I do not know what it means. Any advise and help might be usefull.
I can manage to translate if you write in swedish, thank you.