My 2yo ds has always needed a reasonable amount of sleep and has still had a nap after lunch that often lasted 2 hrs, sometimes more. Although he dislikes having to go to bed, as could obviously be doing something much more exciting 
Just over a week ago he started refusing to nap. Same routine we've been doing for ever (lunch, find appropriate cuddly toys, stories in bed) but now he just gets out of bed and won't go back. He chats and plays by himself for a while before he starts shouting to come downstairs.
I wouldn't mind him dropping the nap except he's started passing out cold falling asleep at about 5 in the afternoon, before we've eaten, and there's no rousing him so he just has to go to bed. This has happen twice now, once at the weekend (a week after his last nap) and again on Monday (2 days later).
Falling sound asleep anywhere except his bed is unheard of. He'll sleep in the car and pushchair but only lightly and wakes very easily. He's obviously very tired to be doing this, it's so out of character! Since he's stopped napping he's been perpetually tired, he tells me he's tired, takes blankets and duvet and makes little nests around the house, but just refuses any attempts to actually sleep.
He's sleeping the same at night though, about 10 hours straight. He did this when he napped and it's stayed the same since he's stopped napping.
Anyone had this?
Is it a phase or are we just going to have to stick it out until he learns to sleep longer at night?
Any advice welcome!