Ariston Genius Premium Stove - Resolving SP1, SP2, and Err 501: Role of Air Composition

Hello and welcome,

I have a question for users about the Ariston Genius Premium stove. Unfortunately, for a few days my furnace has started to behave strangely. The problem is with the firing and the problem with the lack of flame. It looks like this: in an almost random way, the stove turns on correctly or tries to surprise a few times giving the message SP1, SP2, and most often it throws error 501 (no flame). Due to the problem, I called the service, which first carried out an analysis of the air and exhaust gases.
After 1 measurement, it turned out that O2 in the air intake is at the level of 10%, and CO2 is about 4.5%. The decision of the problems fell on the leak in the chimney.
The chimney has been corrected and today, after another analysis, it turned out that the air is 19% and CO2 1.8% in the intake, but the problem with firing is still the same and the service insists that with such an air composition the stove can behave like this. My question is is it true that with such a mixture the problem is still the same? Where to look for leaks? Is the problem still in the chimney? If so, I will have to break the whole wall

If the boiler is under warranty, replace the motherboard ... it's a waste of time to investigate. These measurements are ridiculous.

Unfortunately, the problem lies in the leakage of the chimney or sucking in its own exhaust gases from the chimney outlet. The boiler can also suck flue gas from the neighbor's chimney if it is too close.
To check it for 100%, remove the plastic plug that is located on the left and right side of the flue gas outlet from the boiler. The boiler will suck air from the room and if it works properly, it means that you have a problem with the chimney.
The content of CO2 in the intake air should be 0% and the amount of oxygen from 20 to 21%, depending on the exhaust gas analyzer.
Replacing the board won't do anything.

Thanks for the answers. Unfortunately, the problem is that with the cap removed it is exactly the same.

hello again,

managed to deal with the chimney and the analyzer shows the correct mixture. Unfortunately, the problem with the stove is still there and it does not work properly. When the stove starts it works ok, but unfortunately after warming up you have to wait a long time for the stove to cool down and start again. Often the temperature in the boiler has to drop to

My oven was doing the same thing in my house. The cause was a loose plug on the chimney - the stove was sucking in its own fumes. nb. the end cap after 4 years of use was suitable for replacement - the rubber was quite scorched.