Your home has two main subsystems: supply (fresh water under pressure) and drainage (wastewater by gravity).
Supply: Water enters via meter, main shut-off valve nearby. Cold water direct; hot via water heater (set to 120°F). Fixtures have individual shut-off valves.
Drainage (DWV): Pipes slope 1/4 inch per foot downward. Traps seal gases; vents allow air flow.
Key Principles:
Gravity pulls waste down.
Pressure pushes supply water up.
Water seeks its level in traps.
Locate your main shut-off valve and test fixture valves. Watch Roger Wakefield's video for visuals.
Why this step matters:
-Builds foundation to diagnose issues without guesswork
-Prevents costly damage by knowing shut-off locations
1-2 hours
Notebook for notes, Flashlight, Phone for photos
$0
Definition of Done
•Can diagram supply vs. drain systems
•Located and tested main shut-off valve
•Explains role of traps, vents, gravity
Common Mistakes to Avoid
❌ Ignoring local codes before DIY
→Check municipal plumbing code online first
❌ Not knowing shut-off valve location
→Label and test valve immediately
2
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