Basic Plumbing Troubleshooting

SHUT-OFF VALVES — FIND THESE BEFORE YOU NEED THEM:

FIXTURE SHUT-OFFS (under sinks and behind toilets):
  - Toilet: oval or football-shaped valve on the wall behind
    the toilet, near the floor. Turn clockwise to close.
  - Under-sink: two valves (hot and cold) on the supply lines
    under the cabinet. Turn clockwise to close.
  - Test these now — they can seize from disuse. If you can't
    turn one, spray with WD-40 and try again slowly.

MAIN WATER SHUT-OFF:
  House: usually near the water meter (front of house, near
    street), OR in the basement/utility room where the main
    line enters the house.
  Apartment: usually in a utility closet or behind a panel in
    your unit, OR in a shared utility room (ask building super
    for its location and get a photo).
  Turn clockwise (or use a water meter key for outdoor meters).

GAS — DO NOT TOUCH:
  Gas lines are NOT covered by this skill. If you smell gas,
  leave the building immediately and call 911 or your gas
  utility's emergency line.

DIAGNOSIS:
[ ] Single fixture slow/blocked: clog is in that fixture's trap
    or drain line. Start with the manual methods below.
[ ] Multiple fixtures slow: clog is downstream (main line).
    This likely needs a plumber's snake (or call a plumber).
[ ] Kitchen sink after garbage disposal use: likely grease
    or food buildup in the trap or P-trap.

BOILING WATER METHOD:
Works for: grease clogs in kitchen sink only
Do NOT use for: toilets, bathroom hair clogs, or if your
  drain pipes are clearly plastic PVC (risk of joint damage)

1. Boil a full kettle of water.
2. Pour it slowly directly down the drain in 2-3 stages,
   waiting 30 seconds between each pour.
3. Run hot tap water to flush.
4. Repeat once if needed.

BAKING SODA + VINEGAR METHOD:
Works for: light to moderate clogs
Tools needed: 1/2 cup baking soda, 1 cup white vinegar, kettle

1. Remove any drain cover.
2. Pour 1/2 cup baking soda directly into the drain.
3. Follow immediately with 1 cup white vinegar.
4. Cover the drain opening with a cloth or stopper
   (this forces the reaction into the clog, not back out).
5. Wait 15-20 minutes.
6. Flush with hot (not boiling) water.

Why not Drano/chemical drain cleaners:
  - They damage older pipes (especially cast iron and PVC)
  - They don't work on hair clogs (only dissolve grease)
  - If they fail, you now have a drain full of caustic liquid
    that's dangerous for a plumber to work in
  - They damage your pipes over time

SINK PLUNGER METHOD:
Tools: cup plunger (the flat-bottomed one — NOT the flange
  plunger used for toilets)

1. Remove the drain stopper if there is one
   (most pop out or unscrew counterclockwise).
2. Fill the sink with 2-3 inches of water
   (creates seal for suction).
3. Cover the overflow opening (the hole near the top rim
   of the sink) with a wet cloth and hold it in place.
4. Place plunger firmly over drain.
5. Pump 15-20 times with short, sharp strokes.
6. Pull the plunger up sharply on the final stroke to
   break the clog loose.
7. Run water to test. Repeat up to 3 times.

P-TRAP REMOVAL:
Tools: bucket, channel-lock pliers (or by hand if plastic)

The P-trap is the curved pipe section under the sink.
Most blockages sit here.

1. Place a bucket under the P-trap.
2. Unscrew the slip-nut fittings on both sides of the
   P-trap (counterclockwise). Most are hand-tight on
   plastic pipes. Metal: use pliers with a cloth to
   protect the finish.
3. Pull the P-trap out. The water and clog will fall
   into your bucket.
4. Clear the clog (usually a compressed ball of hair,
   grease, and soap). Use a wire hanger to pull it out.
5. Rinse the P-trap.
6. Reattach. Hand-tight plus 1/4 turn with pliers.
7. Run water and check for leaks at both joints.
   A slow drip: tighten the slip-nut slightly.

TOILET CLOG RULES BEFORE STARTING:
[ ] Do NOT keep flushing if the bowl is full — you will
    overflow the toilet. One flush attempt, then stop.
[ ] If the bowl is at the rim: wait 5 minutes for water
    to drain before plunging. If it doesn't drain at all,
    the clog may be solid and need a snake.
[ ] Never use chemical drain cleaners in a toilet.

TOILET PLUNGER PROTOCOL:
Tools: flange plunger (the one with the rubber extension
  on the bottom — different from the flat sink plunger)

1. If needed, put on rubber gloves.
2. Add water to the bowl to cover the plunger head
   if the bowl is low.
3. Insert the flange plunger so the flange fits into
   the drain hole at the bottom of the bowl.
4. Start with a SLOW first push to remove air (sudden
   push will splash contaminated water on you).
5. Pump 15-20 times with firm, even strokes.
6. Pull up sharply on the final stroke.
7. Flush to test. Repeat up to 3 times.

WHAT WORKED: Great. Disinfect the plunger and toilet area.
STILL BLOCKED: Try a toilet auger (Step below).

TOILET AUGER USE:
Tools: toilet auger / closet auger (~$20-30 at hardware store)

1. Insert the curved end of the auger into the drain
   with the handle up.
2. Crank the handle clockwise while gently pushing
   the cable into the drain.
3. When you hit resistance, work back and forth
   while cranking to break up or hook the clog.
4. Pull the auger out slowly (it may bring the clog with it).
5. Flush to test.

CALL A PLUMBER IF:
[ ] Auger doesn't clear it after two attempts
[ ] Multiple toilets in the home are blocked simultaneously
    (main line clog — not a DIY fix)
[ ] Sewage is backing up into other fixtures when you flush

RUNNING TOILET DIAGNOSIS:

1. Lift the tank lid and set it safely aside.
2. Listen and look. The most common causes:

   CAUSE A: FLAPPER VALVE LEAKING (most common — 70% of cases)
   Signs: you can hear water trickling into the bowl
     even when the toilet isn't running.
   Test: add a few drops of food coloring to the tank.
     Wait 15 minutes without flushing.
     Color appears in the bowl? The flapper is leaking.

   CAUSE B: FLOAT SET TOO HIGH
   Signs: water is running into the overflow tube
     (the tall open tube in the center of the tank).
   Test: watch the water level. If water runs into
     that tube, the float is set too high.

   CAUSE C: FILL VALVE WORN OUT
   Signs: toilet fills correctly but then keeps
     intermittently refilling every few minutes even
     with no flushes.

FLAPPER REPLACEMENT:

1. Turn off water at the toilet shut-off valve
   (behind and below the toilet, clockwise).
2. Flush to empty the tank.
3. Remove the old flapper:
   - Unhook the two side ears from the overflow tube pegs
   - Unhook the chain from the flush handle arm
4. Take the old flapper to the hardware store to match it,
   OR buy a "universal" flapper (Korky or Fluidmaster brand).
5. Attach new flapper: hook ears onto pegs, clip chain
   with 1/2 inch of slack (not too tight or it won't seal).
6. Turn water back on. Let tank fill.
7. Flush and watch: the flapper should drop and seat firmly.
8. Redo the food coloring test to confirm the fix.

FLOAT ADJUSTMENT:

Ball float (older — round ball on an arm):
  Bend the arm gently downward. This lowers the shutoff
  point. Water should stop 1 inch below the overflow tube.

Cup float (modern — cylinder that slides on the fill valve):
  Pinch the clip on the side of the float and slide it
  downward. Or turn the adjustment screw on top of the
  fill valve counterclockwise to lower the water level.

Target: water sits 1 inch below the top of the overflow tube.

LEAK IDENTIFICATION:

Under-sink supply line drip:
  - Water near the shut-off valves or the lines
    running up to the faucet
  - Fix: tighten the connection nut (clockwise, 1/4 turn
    with pliers at a time). If tightening doesn't stop it,
    the supply line needs replacement (~$10-15 at hardware).
    Shut off the fixture valve first.

Under-sink drain drip:
  - Water appears after using the sink, from the P-trap
    or drain connections
  - Fix: tighten the slip-nuts. If cracked plastic:
    replace the P-trap ($5-10).

Toilet base leak:
  - Water appears at the base of the toilet after flushing
  - Cause: the wax ring seal has failed
  - Fix: toilet must be removed and re-set on a new wax ring.
    This is a 1-2 hour DIY job but requires confidence.
    If unsure, call a plumber — water damage under the
    sub-floor is expensive.

Condensation (often mistaken for a leak):
  - Cold-water pipes "sweat" in humid weather
  - Test: dry the pipe and wrap it in dry paper towel for
    1 hour. Paper is wet but pipe connection is dry?
    That's condensation, not a leak.
    Solution: pipe insulation foam ($3-5 at hardware store).

CALL A PLUMBER IMMEDIATELY IF:
[ ] Water is coming from inside a wall
[ ] The ceiling is staining from above
[ ] You hear water running but all fixtures are off
    (possible hidden leak or running meter)
[ ] Water shows near an electrical panel or outlet
    (water + electricity = emergency)