I have a new Ferroli Maxima 35S bolier which is less than 6 months old. Earlier today it started to emit a loud banging noise followed by an emission of steam from the top. Ferroli have said that the boiler had overheated but are unable to give an explanation why. I was told to let it cool down and then press the reset button. All appears to be working fine. But I would be grateful if someone could explain why this happened. The system is not of the sealed type. The boiler is topped up from a header tank in the loft, so it was not running low on water.