Plumbing

Learn how your home plumbing works and how to stop leaks before they ruin your house.

Plumbing
On this page
  1. The Main Water Shutoff
  2. The Supply Lines
  3. Drains and Vents
  4. Water Heaters
  5. Common Leaks and Water Damage
  6. When to Call a Pro

The Main Water Shutoff

Water damage is a homeowner's worst nightmare. You need to know how to stop water fast. Find your main water shutoff valve today. It is usually in the basement, in a crawlspace, or outside near the street. Turning this valve stops all water flowing into your house. Do this immediately if a pipe bursts. Read up on handling home emergencies so you are prepared to act quickly.

Your main water shutoff valve stops all water entering the house.
Your main water shutoff valve stops all water entering the house.
Tag your valve: Buy a bright yellow paper tag and attach it to your main water shutoff. Make sure everyone in your house knows what it does and how to turn it.

The Supply Lines

The supply system brings clean water to your sinks and showers under pressure. If you poke a hole in a supply line, water sprays everywhere. Older homes might have galvanized steel or copper pipes. Newer homes mostly use flexible plastic tubing called PEX.

Modern homes use flexible PEX tubing, while older homes rely on rigid copper or steel.
Modern homes use flexible PEX tubing, while older homes rely on rigid copper or steel.
Pipe MaterialAverage LifespanTypical Repair CostCommon Issues
Copper50 to 70 years$300 to $500Pinholes from acidic water.
PEX40 to 50 years$150 to $300Rodents can chew through it.
Galvanized Steel40 to 50 years$400 to $800Rusts inside, lowers water pressure.
CPVC30 to 50 years$200 to $400Gets brittle and snaps easily.

Keep in mind that all plumbing costs vary widely by your region, the scope of the job, and the age of your home.

Drains and Vents

Drains do not use pressure. They rely on gravity to pull wastewater out of your house. This means drain pipes are larger and slope downward. Every drain has a curved pipe underneath called a P trap. This trap holds a small amount of water to block sewer gas from entering your home. If a guest bathroom smells bad, the trap might be dry. You can often fix smells and odors just by running the water for a minute to refill that trap.

The curved P trap holds water to block sewer gases from coming up the drain.
The curved P trap holds water to block sewer gases from coming up the drain.

Drains also need air to flow smoothly. Vent pipes stick out of your roof to let air in and gas out. If your sinks gurgle when they drain, you might have a blocked vent on your roof.

Water Heaters

Your water heater works hard every single day. Traditional tank heaters store 40 to 50 gallons of hot water. Tankless heaters heat water on demand. A standard tank heater lasts 8 to 12 years. You can extend its life by flushing the sediment out of the bottom once a year. You should also check the anode rod. This is a metal rod inside the tank that attracts rust so the tank itself does not rust away.

Flushing your water heater removes sediment and extends its life.
Flushing your water heater removes sediment and extends its life.

Average Water Heater Replacement Costs

Remember that replacement costs vary by region, scope, and home age.

Electric Tank$1,000 to $1,800
Gas Tank$1,200 to $2,000
Gas Tankless$2,500 to $4,500
Heat Pump$3,000 to $5,000
Scald warning: Set your water heater temperature to 120 degrees Fahrenheit. Anything higher increases the risk of severe burns, especially for kids and seniors.

Common Leaks and Water Damage

Small leaks destroy homes slowly. A running toilet wastes hundreds of gallons of water a day. A dripping pipe inside a wall rots wood and grows mold. Check the rubber supply hoses behind your washing machine and toilets. If they look cracked or feel stiff, replace them with braided stainless steel hoses. Stainless hoses cost $15 to $30 and rarely burst.

If water does soak your ceiling, you will need to cut out the wet spots and patch the drywall. Check our guide to interior paint and drywall for help making it look new again.

When to Call a Pro

You can fix a lot of plumbing issues yourself. Unclogging a sink or swapping a showerhead is easy work. But messing with the main stack or moving water lines requires a permit and serious skill. Read our advice on DIY versus hiring a pro before you cut into a pipe. A bad plumbing job will flood your house. Plumbers usually charge $100 to $200 per hour. Paying for an hour of expert help is always cheaper than replacing ruined floors.

Frequently asked

Why does my toilet keep running?

A running toilet usually means the rubber flapper inside the tank is worn out. Water leaks past the flapper into the bowl, causing the fill valve to turn on again. You can buy a new flapper for about $10 and swap it out yourself in five minutes.

How do I fix low water pressure in one faucet?

If only one sink has low pressure, the aerator is probably clogged. The aerator is the little screen screwed onto the tip of the faucet. Unscrew it, rinse out the bits of sand or calcium, and put it back on.

Is it safe to use liquid drain cleaners?

Plumbers hate liquid drain cleaners. The harsh chemicals create intense heat that can melt plastic pipes or eat through old metal ones. Buy a cheap plastic drain snake to pull out hair clogs instead.

Why does my water smell like rotten eggs?

This usually happens because bacteria are reacting with the magnesium anode rod inside your water heater. You can fix this by having a plumber replace the standard rod with an aluminum or zinc anode rod.

How long do washing machine hoses last?

Standard rubber hoses last about five years before they get stiff and risk bursting. You should upgrade to braided stainless steel hoses. They cost around $20 and are much less likely to flood your laundry room.

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