hi
@SimoneLesleyOlivia42
my dad too used to fiddle with the controls of things, just because they were there, and I think because of a vestigial memory of doing such things in his home over the years but because he no longer really grasped what the control was for, he was changing things at unhelpful time and in unhelpful ways - he wasn't lying when he said he hadn't done anything, he couldn't remember that he had and so if the controls had been altered, as he didn't remember doing it, he hadn't done it an by implication someone else must have
so I covered over as many of the problem areas as I could, quite literally often just with white card and sticky tape, and was careful with standby lights as he saw those and knew the whatever was still 'on' so went searching for the plug socket, control etc
can you lock the radiator onto a comfortable setting (which will mean higher than is comfortable for you, probably) or have the control completely changed
as Beate says, your granddad isn't telling lies and certainly not to deliberately deceive or be nasty, he is creating a story that explains the situation for which he has information/memory missing, it's called confabulation and can appear very cunning and spiteful as it often, sadly, involves blaming others for something that has happened