This heater doesn't work anymore

I pulled out my portable space boiler the other morning as my bedroom was a little cold even with the central heating and air conditioner unit’s boiler running.

And my portable space boiler did not work anymore.

I am not sure what had happened as I have not used it in a few months, and when I did use it before everything was great and fantastic with it. I did not even understand it one bit. But because I did still want a portable space boiler I decided to just go out to the store and buy a current portable space heater. They had them on sale for cheaper than they usually are, so I guess I made out ok. The current portable space boiler that I bought was the same as the seasoned one that had just broken down. So I was great with all. However it still boggles the mind on what possibly could have happened to make the original portable space boiler not work anymore when I did not even use it or anything like that. It just sat in the closet for months untouched, so I easily can not see what could have possibly happened to the portable space heater. But it is all great and fantastic now because I picked up a brand current and up-to-date portable space boiler of the same exact kind for a little cheaper than what I paid for the original portable space boiler that does not work any longer. I hope this portable space boiler that I bought will last me for a while without not toiling anymore.
Contractor