I have the Heartstart AED from Defib Service Plus at home, yesterday it was the case that the green light stayed on continuously for at least 1 minute, then it started flashing again. My question is is this harmful and what was going on with our AED?

Don’t worry, there is nothing wrong with the AED. During the daily self-test, the light lights up continuously for 1 minute. After the self-test, the AED returns to standby and flashes normally every 5/6 seconds.