Mine is over 4 years old run for over 8000 hours and never been serviced , and it’s running as good as the first day I had it provided it’s run hard and not stop start they don’t need servicing , when they start producing white smoke then it’s time for a new screen and pin and burner housing , will be intresting to see how long it goes on for , but if it went bang tomorrow I cannot complain, and it’s still cheap hot water as far as Ime concerned, much quicker than cold , wish I had gone hot 18 years ago .