What should a first-time homeowner know about plumbing?

This is the first thing to learn, ideally in your first week. When a pipe bursts or a toilet overflows, the minutes it takes to find the valve are the minutes water spreads across the floor.

The main shutoff stops water to the whole house. Where it sits depends on the home, so walk the house and the outside walls until you find it. Your home inspection report is a good place to start: InterNACHI's Standards of Practice require inspectors to describe "the location of the main water supply shut-off valve." Once you find it, make sure you can reach it and turn it.

Fixture shutoffs are the small valves on the supply lines under sinks, behind toilets and behind the washer. They let you stop water to one fixture without shutting off the house. Our guide to how to shut off water to a fixture shows where each one is.

The water heater has its own cold water shutoff on the inlet pipe. A gas water heater also has a gas shutoff. InterNACHI inspectors are required to note the main fuel shutoff too, so check your report for that as well.

More than most new owners expect. In Phoenix, the city says issues on its side, "from the street to the water meter," are the city's responsibility, and "issues after the water meter are the responsibility of the homeowner." That means the water line from the meter to the house is yours.

The sewer side works the same way. The city says owners are responsible for "cleaning and maintaining the sewer line that runs from the house to the connection with the city sewer main in the street or alley." Under City Code Section 28-5, the city repairs broken service lines only within the public right of way. Other Valley cities set their own rules, so check with yours. Our guide to who is responsible for the sewer line in Phoenix goes deeper. The code itself makes the owner responsible for keeping the plumbing in safe working order, as why plumbing code matters for homeowners explains.

While you're outside, find two more things:

• The water meter, usually in a box near the curb. You'll use it for leak tests.
• The sewer cleanout, a capped pipe near the house or along the sewer line's path. A plumber uses it to clear the main line. Our page on what a sewer cleanout is shows what it looks like.

If the house has a septic system instead of city sewer, the rules change. See how to tell if you have septic or city sewer.

### What should you know about water pressure?

Too much pressure can damage plumbing, and a private regulator is the owner's responsibility. IPC Section 604.8 requires a pressure reducing valve, or PRV, when pressure within a building exceeds 80 psi static, and the valve must reduce it to no more than 80 psi static. Phoenix's design standards also require a private regulator on the customer's side of the meter where local static pressure exceeds 80 psi. The city's customer service guidance includes conflicting 80 and 120 psi wording; that does not change the building-static code limit. See whether you need a pressure reducing valve for the distinction, and confirm local amendments if the home is outside Phoenix.

The EPA says fixtures work best at 45 to 60 psi. To check yours, buy a pressure gauge that threads onto a hose bibb, turn off every fixture in the house, attach the gauge and open the bibb all the way. Our guides to what home water pressure should be and whether you need a pressure reducing valve explain the next step.

Two habits do most of the work: keeping grease out of the drains and checking for leaks now and then.

For the everyday problems every home runs into, and how to prevent each one, see the most common plumbing problems and how to prevent them.

### Keeping drains flowing

The biggest one is keeping grease out. The City of Phoenix says grease is "the most frequent cause of sewer problems." Hot water doesn't help: the city says grease poured down the drain "eventually cools down, congeals, builds up, and hardens," forming a plug. Let it cool and put it in the trash.

A few more habits help:

• Use strainers in sinks and tubs to catch hair and food.
• Flush only toilet paper. Wipes, even ones labeled flushable, and paper towels can clog the line.
• Scrape plates into the trash, not the disposal.
• Know the warning signs: several slow drains at once, gurgling, or water coming up in a tub or floor drain can mean a main line problem.

Our guides to what not to put down the drain and common kitchen plumbing problems cover the rest. Keep a plunger for each toilet, and skip harsh chemical drain cleaners.

### Catching leaks early

With two free checks the EPA recommends:

1. 1Compare your bills. Look at each month's water bill against the same month last year. A big jump can mean a leak you haven't found.
2. 2Test at the meter. Read the meter at a time when no water is being used, then read it again two hours later. The EPA says that if the reading has changed, "you probably have a leak in your home."

Leaks add up. The EPA's Fix a Leak Week page says the average household's leaks can waste "more than 9,300 gallons of water" every year, and that common leaks like "worn toilet flappers, dripping faucets, and other leaking valves" are "often easy to fix." Our guide to a water meter leak test walks through it, and our page on the signs of a slab leak in Arizona covers the leaks you can't see.

A little care once a year. The EPA suggests:

• A regular look for leaks, aged gaskets, loose connections and corrosion.
• A flush once a year to reduce sediment buildup.
• A check of the temperature and pressure relief valve at least once a year.

The EPA adds that it "may be best to hire a professional to service your home's water heater at least once a year." Find the heater's label too. It lists the capacity, and the serial number often tells you when it was made. Our guides to how often to flush a water heater in Phoenix and whether to repair or replace a water heater help you plan ahead.

### And the water softener?

If the house came with one, check the salt level regularly and break up any hard salt crust, which the EPA calls a salt bridge. Clean the brine tank once a year. The EPA also suggests a professional service once a year. Our guide to why Arizona homes use water softeners explains what it does.

### What can you fix yourself, and when should you call?

Plenty of small jobs are fine for a new owner: a toilet flapper, a clogged aerator, a plunger on a slow toilet, a loose trap nut. The EPA's WaterSense program has step-by-step help for common leaks. Call a plumber for anything involving gas, a water heater that leaks, pressure over 80 psi, a sewer backup, or water coming through a wall or ceiling.

For a full list of what to check and when, see our yearly plumbing maintenance checklist. HQ Plumbing & Air helps new homeowners across the Phoenix area with everything from pressure regulators and water heaters to leaks and sewer lines. We're available 24/7, licensed and insured, and every job starts with a free estimate and upfront pricing. See our residential plumbing services.

Learn where the shutoff is this week. It's the one plumbing fact you'll need in a hurry.

Got an inspection report in hand? See how to read its plumbing section.