If you never get anything inspected, then the likelihood that some part of your plumbing system will eventually malfunction is 100%.
Nothing lasts forever. Just consider these nightmare situations.
Water Heater – You wake up one morning, and your water heater is broken. How can you tell? After 10-12 years of hot water, your morning shower starts off ice cold. If it burst, there is now a huge mess in the downstairs area of your house.
Supply/Drainage Pipes and Valves – You notice a large puddle behind your toilet and bend down behind it to try to tighten the valve with a pair of pliers. The old nut on it has a lot of mineralizing on it and breaks when you try to move it. Now the water is flooding your bathroom.
Kitchen Appliances – You think you’ve never had a problem with your kitchen sink. If it ever gets clogged, you just pour some drain cleaner down, and it’s fixed. Then one day you have your dishwasher replaced and notice that the floor is severely warped. There’s no telling how a leak under your sink has been slowly destroying your home.
Sewer – You leave the bathroom one day and hear ominous gurgling behind you. This can be an indication of much more sinister–and costly–things at play.
The cost of repairing these after they’ve broken can be in the thousands. Why risk it?