Plumbing Common Findings

Backflow Prevention / Missing Reducer or Backflow Preventer

What It Is

A backflow preventer is a device on a water supply line that keeps water from flowing in reverse — back toward the supply source — under certain pressure conditions. When that happens, contaminants or non-potable water can get into a potable water line.
The type of device required depends on where it is and what it is connected to. Common residential locations include hose bibs (outdoor spigots), irrigation systems, and certain appliance connections.

Why It Gets Noted

When backflow prevention is missing where it is required or recommended, it gets noted. The concern is that a sudden pressure drop in the supply line could allow water — and whatever is in it — to travel the wrong direction.

How Common Is It

Missing hose bib vacuum breakers are one of the more common plumbing findings in residential inspections. They are inexpensive to add and are frequently absent on older hose bibs that predate code requirements.

What Is Generally Recommended

Evaluation by a qualified plumber is recommended to confirm the right type of device for the specific application and make sure it is properly installed.

S-Trap / Improper Drain Trap Configuration

What It Is

A plumbing trap is a curved section of pipe beneath a drain — under a sink, for example — that holds a small amount of water at all times. That standing water forms a seal that keeps sewer gases from traveling back up through the drain and into the home.
An S-trap gets its name from its shape, which resembles the letter S when viewed from the side. Unlike the current standard P-trap, an S-trap routes the drain straight down into the floor rather than through a wall. Because of that shape, a large volume of water draining at once can pull the water seal right out of the trap — similar to how siphoning gas out of a tank works.

Why It Gets Noted

Once the water seal is gone, sewer gases can come back up through the drain and into the living space. Sewer gases can include hydrogen sulfide and methane, which are unpleasant at low levels and can be hazardous at higher concentrations. A gurgling sound from the drain is sometimes a sign the trap seal has been siphoned out.
S-traps were allowed under older plumbing codes and still show up frequently in older homes. They are not permitted under current plumbing standards, which require a properly vented P-trap that prevents siphoning from occurring.

How Common Is It

S-traps are one of the more common plumbing findings in older homes, particularly at kitchen and bathroom sinks where the original plumbing has not been updated. Finding one does not mean the plumbing is failing, but correction is generally recommended.

What Is Generally Recommended

Evaluation and correction by a qualified plumber is recommended. The typical correction is reconfiguring the drain to a properly vented P-trap.

Improper Plumbing Vent / Vent Not Terminating Properly

What It Is

A plumbing vent is a pipe that runs from the drain system to the exterior of the home, typically exiting through the roof. It does two things: it lets sewer gases escape safely to the outside, and it lets air into the drain system so water can flow properly without gurgling or pulling the seal out of nearby traps.

Why It Gets Noted

When a vent ends in the wrong place — inside a wall cavity, in an attic, or anywhere short of a proper exterior termination — sewer gases that should be exhausting outside can end up in spaces they should not be. It can also cause drain problems elsewhere in the system.

How Common Is It

Improper vent terminations turn up most often in older homes or where plumbing work has been done without a permit or inspection.

What Is Generally Recommended

Evaluation and correction by a qualified plumber is recommended to make sure the vent terminates at a proper exterior location.

Water Heater Past Expected Service Life

What It Is

Most residential tank-style water heaters have an expected service life of approximately 8 to 12 years, though the actual lifespan varies depending on the brand, water quality, maintenance history, and usage. The manufacture date is typically on the unit's data plate and is often encoded in the serial number.

Why It Gets Noted

A water heater at or past its expected service life is noted as something to be aware of. Age alone does not mean the unit is about to fail, but older water heaters are more likely to develop leaks, sediment buildup, corrosion, or efficiency loss. Rust on the unit, at fittings, or at connections is an additional sign worth having looked at.
A water heater that does fail can cause property damage, especially if it is located in a finished area or above living space.

How Common Is It

This comes up in a lot of inspections, particularly in homes that have not had recent mechanical updates.

What Is Generally Recommended

Evaluation by a qualified plumber or HVAC professional is recommended. They can look at the current condition of the unit and give you a better sense of whether replacement makes sense now or is something to plan for down the road.