Bathroom Repairs — the bathroom's most-fixed problems, one room at a time.

You came in through the Bathroom room hub — here's everything repair-related for the bathroom. 49 guides covering toilets, faucets and valves, drains and venting, shower and tub systems, tile and grout, and the GFCI-protected electrical work that every bathroom eventually needs. This is the same content you'd reach by entering through the Repair lane's Bathroom slice; both URLs serve the same intersection because the site supports two equally valid mental models — "I'm in the bathroom, what can I fix?" and "I want to repair something, what room am I in?"

The bathroom has the highest consequence per square foot of any room in the house. A running toilet wastes 200 gallons a day. A failed wax ring allows sewer gas into the living space. Grout that goes two years without attention becomes a subfloor replacement conversation. The repairs in this section are not dramatic — most take under an hour and cost under thirty dollars. What's dramatic is the cost of not doing them. The bathroom is where deferred maintenance compounds fastest.

How to use this menu

This page is the Bathroom × Repair intersection — two entry points to the same 49 guides. Browse by the five highest-search repairs below if you came here from Google, or use the category menu to find what broke by system. Every guide linked here is a leaf page that Iris builds on demand — click any guide title to read the full step-by-step, with tools, materials, time estimate, and common pitfalls.

Five highest-search bathroom-repair projects

If you came here from a search engine, you came for one of these five. They represent the bulk of bathroom repair searches, and all five are within DIY range for a careful first-timer.

1. How to fix a running toilet

30 minutes. $10–35. Beginner. A toilet that refills on its own every few minutes is losing water through the flapper or the fill valve. Most of the time it's a $7 flapper that takes fifteen minutes to replace. The fix that costs thirty dollars today prevents the leak that costs three hundred dollars if the water reaches the ceiling below. Read the running toilet guide →

2. How to replace a toilet flapper

15 minutes. $5. Beginner. The toilet flapper is the rubber seal over the flush valve drain. It wears out every three to five years regardless of brand, and replacing it is the fastest plumbing repair in the house. The only decision before you buy: check the flush valve seat first. A pitted seat will defeat a new flapper in a week. Read the flapper guide →

3. How to fix a leaky shower faucet

60 minutes. $20–80. Intermediate. A dripping shower faucet is almost always a worn cartridge — the internal valve that controls water flow. Moen, Delta, and Kohler each use brand-specific cartridges you pull and replace. Identify your brand and model before you disassemble anything, because you want the right part in hand before the water is off. Read the shower faucet guide →

4. How to unclog a bathroom drain

30 minutes. $5–15. Beginner. Bathroom drains clog with hair and soap buildup. Pull the stopper, remove the clog by hand or with a drain snake in two passes, flush with hot water. If the drain is still slow after two passes with the snake, you're looking at a venting issue, not a clog — a different repair entirely. Read the drain guide →

5. How to regrout a tile shower

4 hours plus cure time. $30. Intermediate. Cracked grout in a shower surround isn't cosmetic — it's a waterproofing failure. Water that reaches the substrate grows mold, rots the backer board, and eventually damages the subfloor. Regrout every five to seven years. The caulk joints at the tub-to-tile seam need replacing every two to three years. Read the regrout guide →

The full bathroom-repair menu, by category

49 guides total, organized by the system that failed.

Toilet repairs (12 guides)

Running toilets, ghost flushes, rocking toilets, slow flushes, handle failures, and the wax ring that seals the toilet to the drain flange. The toilet is the most-used mechanical device in the bathroom and has about twelve distinct failure modes — all of them fixable without a plumber if you have the right part and thirty minutes. Start with the flapper; work your way to the wax ring.

Faucet & valve repairs (10 guides)

Bathroom sink faucets, shower cartridges, tub spout diverters, and the shutoff valves under the sink that need replacing before you can repair anything else. Every single-handle bathroom faucet has a cartridge or a ceramic disc valve inside. The cartridge is the repair — get the brand-specific replacement before disassembly. Shower faucet repair →

Drain & venting (8 guides)

Slow drains, complete clogs, floor drains that smell like sewer, and the P-trap that needs replacing when the drain arm shifts. S-traps are illegal under current plumbing code because they siphon dry — if your bathroom sink drain terminates vertically, that's an S-trap, and it's worth replacing with a P-trap and vent. Drain unclogging guide →

Shower & tub repairs (9 guides)

Shower arm replacement, diverter valve repair, tub spout removal, shower pan cracks, and the caulk bead between the tub and tile surround that fails every two years without exception. The shower is the wettest zone — every failure here is a waterproofing failure first. Address shower repairs on the first sign of a leak, not after the water has reached somewhere it shouldn't be.

Tile, grout & caulk repair (5 guides)

Cracked grout lines, missing grout in corners, failing caulk at the tub-to-tile seam, and the tile that's come loose because the thinset adhesion has failed. The caulk joint at the tub transition is silicone, not grout — use the right material and it lasts three years; use the wrong one and it lasts three months. Regrout guide →

Vent fan & lighting (5 guides)

Bath vent fan motor replacement, fan-and-light combo repairs, GFCI outlet replacement, vanity light fixture swap, and the exhaust damper that sticks open in winter. The bath fan is the room's moisture control — when it stops moving air effectively, mold follows within six months. Fan motor replacement costs twenty-five dollars and forty-five minutes; mold remediation costs four thousand dollars and a week.

Five mistakes specific to bathroom repairs

These five mistakes come up on bathroom jobs specifically because the bathroom has failure modes — both plumbing and electrical — that don't appear in other rooms. Each one turns a simple repair into a repeated repair or a larger one.

Replacing a flapper without checking the flush valve seat. A new flapper on a worn or pitted seat will leak again within a week. Before installing a new flapper, run your finger around the flush valve seat. If it's rough, ridged, or has mineral buildup, address the seat first.

Using channel-lock pliers on chrome supply lines. Compression fittings on braided supply lines need hand-tight plus a quarter turn — not pliers. Channel-locks on chrome fittings crush the nut, score the ferrule, and guarantee the leak you were trying to stop. Use an adjustable wrench with a protective rag.

Caulking over old caulk. New silicone over old silicone lifts at the seam within ninety days. The only effective re-caulk is a complete removal of the old bead, a rubbing-alcohol wipe, a 24-hour dry, and a fresh application. Anything less is decorative, not waterproofing.

Working on a GFCI outlet without confirming the breaker AND the GFCI test. The breaker and the GFCI are independent protection systems. Confirm both with a non-contact voltage tester before touching any terminal. The test takes two minutes and is the single most important safety step in bathroom electrical work.

Trying to thread an ABS DWV trap without primer. ABS cement requires purple primer on every joint. A dry-fit trap looks finished and holds pressure for months — then opens slowly into the cabinet below. Always primer, always cement, always in that order.

Tools that earn their place in bathroom repair specifically

The 10-project bathroom-repair starter sequence

If you've never repaired anything in a bathroom and want a sequence that builds skill efficiently, these ten projects in order form a deliberate skill ladder. Each project teaches a technique that the next one assumes.

  1. Replace toilet flapper. 15 min. The fastest plumbing repair in the house. Teaches tank anatomy and water shutoff at the supply valve.
  2. Caulk a tub gap. 45 min. Teaches tape-bead-tool-peel caulk technique that applies to every wet seam in the house.
  3. Tighten loose toilet handle. 10 min. The handle nut is reverse-threaded; most people strip it turning the wrong direction. Teaches thread direction awareness.
  4. Replace shower head. 20 min. PTFE tape on threads, hand-tight plus a quarter turn. Teaches thread protection and connection torque.
  5. Fix slow drain (snake or enzymatic cleaner). 30 min. Teaches stopper removal and drain snake use.
  6. Replace toilet fill valve. 30 min. More involved than a flapper; teaches the full tank anatomy and overflow tube relationship.
  7. Reseat a wobbly toilet (new wax ring). 90 min. Teaches water shutoff, drain disconnection, toilet weight, and wax ring installation.
  8. Replace cartridge in single-handle faucet. 60 min. Brand-specific; teaches valve body anatomy and handle-cap removal.
  9. Regrout a small tile section. 3 hr + cure. Teaches grout saw, float angle, haze removal, and silicone caulk at transitions.
  10. Replace bath fan motor. 45 min. Electrical shutoff at breaker + GFCI test; motor slides out on a carriage. Teaches the sequence of bathroom electrical safety confirmation.

Six common questions about bathroom repairs

Why does my toilet refill on its own every few minutes?

The toilet is ghost-flushing because water is leaking from the tank into the bowl. The two culprits: a worn flapper that no longer seals, or a fill valve set too high that overflows the overflow tube. Add food coloring to the tank — if color appears in the bowl without flushing, replace the flapper. If water is running over the overflow tube, lower the float.

What's the difference between a P-trap and an S-trap?

A P-trap has a horizontal outlet and maintains its water seal by geometry. An S-trap has a vertical outlet, is illegal under modern plumbing code in most jurisdictions, and can siphon dry — allowing sewer gas into the room. If your bathroom sink drain exits vertically downward, you likely have an S-trap and should replace it with a P-trap and proper venting.

Should I caulk between the tub and the tile?

Yes — 100% silicone, never grout. The joint flexes with temperature and water weight; grout is rigid and will crack within months. Re-caulk every two to three years regardless of appearance — silicone fails from the inside before it fails visually.

Can I just paint over moldy caulk?

No. Painting over mold traps it and lets the colony continue growing underneath. Cut out the old caulk, scrub with a dilute bleach solution, let dry 48 hours, confirm no remaining mold, then re-caulk with fresh silicone.

Why does my bathroom smell like sewer?

Two common causes: a dry trap (a rarely-used fixture whose water has evaporated) or a failed wax ring (the toilet rocks, the seal has cracked, and sewer gas escapes around the base). Run water in unused fixtures. If the toilet shifts more than 1/8 inch in any direction, reseat it with a new wax ring.

How often should I replace a wax ring?

Only when you pull the toilet — not preventively. A correctly-installed wax ring on a properly-anchored toilet lasts 20 to 30 years. Always use a new ring when reinstalling — they cost $5, and you never want to reseat a toilet twice.

The four bathroom-repair techniques worth mastering

1. The leak-isolation test

Turn off the main water supply to the bathroom. Note the water meter or pressure gauge position. Wait 15 minutes. If the pressure has dropped, the leak is upstream of the shutoff — a supply line or valve issue. If it holds, the leak is at the fixture. This test distinguishes between a DIY repair and a plumber call in fifteen minutes.

2. The continuity check before any electrical repair

Flip the breaker, then use a non-contact voltage tester at the device. If it reads live, the GFCI is on a different circuit or is being back-fed. Test the GFCI with its own TEST button and verify downstream outlets lose power. Test at the panel again. The sequence takes two minutes and is the single most important safety protocol in bathroom electrical work.

3. The right way to caulk

Apply painter's tape on both sides of the seam with a 3/16-inch gap. Fill with a single continuous silicone bead at 45 degrees. Draw a wet finger or caulk tool across in one pass. Remove tape while the silicone is still wet. Wait 24 hours before water exposure. The tape removes the skill ceiling — the single pass determines the result.

4. The plumber's putty vs. silicone vs. Teflon tape decision

Plumber's putty: below-sink fixtures where a flexible waterproof bed is needed. Not for plastic or composites. Silicone caulk: tub-to-tile seams and any wet surface that flexes. Teflon tape: threaded plumbing connections — supply lines, shower arms, fill valves. Three wraps clockwise on the male thread. Using the wrong material for the job is how leaks begin.

Cost-to-payback ranking — which bathroom repairs save the most fastest

Not all bathroom repairs are equal in urgency. Here's how they rank by the combination of cost-to-fix, water/money saved, and damage-deferred if ignored.

One more thing — the order bathroom repairs should be done in

When multiple bathroom repairs are pending, sequence matters. Turn the water off first — even for repairs that seem dry. Fix the leak you can see before you fix anything cosmetic; a visible drip is always covering a slow leak somewhere it can't be seen. Find the leak you can't see before it reveals itself through a ceiling or a floor. Then replace the parts that are still technically working but old — the flapper that's five years old, the caulk line that's two years past its service life, the wax ring you've never changed. That's the order: visible leaks, hidden leaks, aging parts. Everything else is optional.

About this intersection

This page is the Bathroom × Repair intersection — one of 60 task-lane × room intersection pages on HowTo: Home Edition. It exists at two equivalent URLs by design: /en/bathroom/repair/ (room-first) and /en/repair/bathroom/ (lane-first). Both are real pages with real content; both serve the same purpose; both link to the same 49 leaf-level repair guides. The dual entry points let users navigate the way they think.