Plumbing
How your home plumbing works, pipe types, common repairs, water heaters, and when to call a professional.
How Your Home Plumbing Works
Every home plumbing system has two subsystems: the supply system brings fresh water in under pressure, and the drain-waste-vent (DWV) system carries wastewater out by gravity.
- Supply Lines — Hot and cold pressurized water (40-80 PSI) from the municipal main or well. Main shutoff is typically near the meter.
- Drain-Waste-Vent (DWV) — Gravity-fed drains carry wastewater to the sewer/septic. Vent pipes allow air in to prevent siphoning traps.
- Water Heater — Heats cold supply water. Connected between the cold supply line and the hot distribution lines throughout the house.
- Fixtures — Sinks, toilets, tubs, and showers. Each has supply connections, a drain, and a P-trap to prevent sewer gas backup.
- Shutoff Valves — Main shutoff near the meter, plus individual shutoffs at each fixture. Know ALL locations before emergencies.
Common Repairs
Leaky Faucet (Beginner - DIY)
- Compression (Washer): Remove handle, unscrew packing nut, replace rubber washer and O-ring. Most common in older two-handle faucets.
- Cartridge: Pull out cartridge, replace with exact match. Bring old cartridge to hardware store for matching.
- Ball: Replace the ball assembly, springs, and seats. Ball faucet repair kits are inexpensive (~$5-10).
- Ceramic Disc: Remove and clean or replace the disc cylinder. These rarely fail but when they do, replacement is best.
Tools: Adjustable wrench, Screwdriver set, Plumber's grease, Replacement parts
Tips: Turn off supply valves under the sink first | Plug the drain to avoid losing small parts | Take photos during disassembly for reference
Running Toilet (Beginner - DIY)
- Worn Flapper: Most common cause. Turn off water, flush to empty tank, unhook old flapper, install new one (~$5). Universal flappers fit most toilets.
- Faulty Fill Valve: Replace the entire fill valve assembly (~$8-12). Turn off water, disconnect supply line, swap old for new.
- Float Too High: Adjust the float so water stops about 1 inch below the overflow tube. Bend the float arm or adjust the screw on cup-style floats.
Tools: Adjustable wrench, Replacement flapper or fill valve, Towels, Bucket
Tips: A running toilet can waste 200+ gallons per day | Drop food coloring in tank — if it appears in bowl without flushing, the flapper is leaking | Replace flappers every 3-5 years preventively
Clogged Drain (Beginner - DIY)
- Plunger: Use a cup plunger for sinks, a flange plunger for toilets. Create a tight seal and plunge vigorously 15-20 times.
- Drain Snake: Insert snake into drain, crank to extend through the clog. Pull back to retrieve debris. Works for clogs plunger can't reach.
- Enzyme Cleaner: Pour enzyme-based drain cleaner for slow drains. Takes hours to work but safe for pipes. Avoid chemical drain cleaners — they damage pipes.
Tools: Cup plunger, Flange plunger, Drain snake (25 ft), Enzyme drain cleaner
Tips: NEVER use chemical drain cleaners (Drano, Liquid-Plumr) — they corrode pipes | Prevent clogs: use drain screens, avoid pouring grease | If multiple drains are slow, the problem may be in the main line — call a plumber
Pipe Types
| Type | Use | Lifespan |
|---|
| Copper | Supply lines, both hot and cold | |
| PEX | Supply lines, hot and cold | |
| CPVC | Hot and cold supply | |
| PVC | Drain lines and vent pipes ONLY | |
| Galvanized Steel | Old supply/drain lines (pre-1960s homes) | |
Water Heaters
When to Call a Professional
- Gas line work — Gas leaks can cause explosions. Licensed plumbers only. Never DIY.
- Sewer main line — Requires specialized equipment (camera inspection, hydro-jetting). Major code implications.
- Water heater installation — Gas connections, venting, code requirements, and permits typically required.
- Frozen/burst pipes — Risk of flooding and further damage. Professionals can thaw safely and repair quickly.
- Repiping the house — Major project requiring permits, wall access, and code compliance.
- Sewer smell throughout house — Could indicate broken vent pipe, dried trap in unused drain, or cracked sewer line.
- Low water pressure (whole house) — May indicate main line issue, pressure regulator failure, or corroded galvanized pipes.