If you are purchasing a house and have it under contract in the due diligence period, your real estate agent will recommend that you hire a home inspection company to check it out. They will further advise you that this professional will check all aspects of the home, including the plumbing, so there is no reason for you to call individual companies. This advice does tend to work out well for the majority of situations, but that doesn’t mean you couldn’t benefit by having a few specialized professionals do a more thorough inspection.
One situation where you might want to call in a plumber to do an inspection before you close on a house is when it is an older home. A standard inspection will only ascertain if the plumbing connections are working. They might not have extensive knowledge about older pipe materials that should be replaced due to inherent problems with them that can often result in major failure and flooding the home.
Another reason to call a plumber to do the inspection is if you are using nearly all of your savings for your down payment and would be hard-pressed to deal with a plumbing issue if it came up shortly after closing. A plumber is more likely to spot a weakness that isn’t yet symptomatic. They can also advise you about upgrades that you should consider in the coming months so you can budget accordingly, perhaps by dropping your offer by a few hundred dollars to accommodate the anticipated expenditure.
The bottom line is that you can never have too much information about a house you are about to make a sizeable investment in, so calling a plumber as a second set of eyes is never a bad idea.