pretty good.. it does the job . nice hot water the only issue i have with mine is when i change the gas bottle it seems to get a air lock in the pipe and it takes a while for it to get started.. its a small issue because once it clears its fine until i change the bottle over.. something i can live with .. ive had it 2 months now and spent 73 quid on gas so about a tenner a week but i have it on all the time . i haven't got it vented as its near the back of the van, with the back door open when in use .again no issues with that either