WorldsPantry My assumption would be a failure of the temperature probe. If it was disconnected in some way you would get an alarm, so it’s most likely misreading. This is based on the information you gave, although it might not be the problem..
The most important piece of information, is the thing you have not mentioned..when you switch it on from cold what does it read and what happens over the next 3 minutes?
Tell us the above and I “might” have some more tests for you.
It would be great if you could also tell us the year of manufacture, or how old the machine is.
