Justin Bieber and his wife, Hailey, have learned a valuable lesson -- before you drop a ton of cash on a new home ... double-check the pipes.
Sources close to the Biebers tell TMZ ... they were forced to leave their $100k/month crib in the San Fernando Valley last month after a major plumbing issue arose, among other problems.
We broke the story ... JB signed a lease to rent the 4 bedroom, 7 bathroom Mediterranean-style house in October, but we're told the couple's had a bunch of issues.
A pool heater broke, there was trouble with the AC and a pipe burst ... which our sources say was the final straw.
They've moved out, but there's no worry the landlord will go after them for breaking a lease. We're told this was a month-to-month deal, so they're in the clear.
Justin and Hailey have been staying at a Beverly Hills hotel ever since, and if the vid of Justin singing in front of the hotel is any indication ... they've been making the most of it.
But now, we're told they want a place of their own, so they're on the hunt. As for whether they'll commit to buying, our sources say the couple's on the fence.