Yep
That's why boilers which supply stored hot water generally last for decades, because they're not subjected to so many on-off cycles. The one I've just got rid of in my house (still working, but hideously inefficient) has been there easily 25 years, and only broke down twice in the 10 years I've been there.
(JohabMorelli is spenging merrily away, Wed 7 May 2008, 14:38, Reply)