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Toilet Repair Guide — Diagnostic Flowchart for Any Brand

Universal toilet repair diagnostic across all brands. Most repairs are achievable DIY in 30-60 minutes with universal Korky/Fluidmaster aftermarket parts ($5-$50). Some brand-specific exceptions noted (Eljer 3-inch shank, Kohler AquaPiston, TOTO proprietary, Saniflo macerator).

Updated May 2026 · Toilets

Universal toilet repair — start here

Most US residential toilet repairs (across Kohler, AmStd, Sterling, Vortens, Mansfield, Gerber, Glacier Bay, and most other brands) use universal aftermarket parts available at every Home Depot and Lowes. This guide diagnoses by symptom and recommends the correct universal part. Brand-specific exceptions are flagged.

Universal repair diagnostic flowchart

SymptomCauseUniversal partBrand-specific exceptionsCost (~)Repair time
Continuous running waterFlapper not sealingKorky 2032BP (3-inch)Kohler AquaPiston models: Kohler canister rebuild kit. TOTO: TOTO OEM. Eljer Aqua-Saver II: 091-7115 cartridge.$7-$6015-45 min
Phantom flushes (sporadic refill)Flapper slow leakKorky 2032BPSame as above per brand$7-$6015-45 min
Tank refills slowlyFill valve wornFluidmaster 400AEljer: 3-inch shank requires 091-7320 OEM or 400UAK adapter. TOTO: TOTO OEM fill valve. Kohler designer: GP1083167 OEM optional.$10-$5025-35 min
Tank refills incompletelyFill valve shut-off too low OR fill valve wornAdjust fill valve OR replaceSame as above per brand$0 or $10-$5010-35 min
Toilet won't flushChain disconnected, broken trip leverKorky 6071BP universal chromeNone — handles universal$0 or $8-$285-15 min
Weak flush (incomplete bowl evacuation)Chain too tight OR partial clogAdjust chain OR plumbing serviceNone — adjustment universal$0 or $50-$2005 min or 1 hr
Leak at tank-bowl jointGasket failedBemis 7530 (3-inch universal)Eljer: wider pattern requires 091-7355 OEM or Bemis 7560 wider universal.$5-$1845-60 min
Leak from base (where toilet meets floor)Wax ring failedKorky 6000 wax ringNone — wax rings universal$5-$1060-90 min
Leak from supply line at fill valveSupply line worn or looseReplace supply line OR tightenNone — supply lines universal$0 or $5-$1010 min
Wobbly toiletFloor flange bolts looseTighten flange boltsNone — universal$015 min
Cracked tank or bowlPorcelain damageFull toilet replacementCheck warranty: TOTO 1-year, Kohler 1-year tank trim + warranty varies, Eljer/Mansfield/Vortens/Sterling lifetime porcelain.$0 if warranty, else $110-$580+90 min

Brand-specific repair gotchas

Eljer (proprietary 3-inch fill valve shank)

Eljer toilets do NOT accept Fluidmaster 400A directly. Use Eljer 091-7320 OEM ($35-$50), Fluidmaster 400UAK adapter kit ($18-$25), or Korky 528MP universal multi-shank ($16-$20). Eljer trip lever uses LEFT-HAND threading (turn RIGHT to loosen).

Kohler (AquaPiston canister flush)

Cimarron, Highline, Memoirs Stately, Maxton, Veil Smart, Numi, Persuade, Adair, and most current Kohler models use AquaPiston canister flush — NOT a flapper. Service requires Kohler AquaPiston rebuild kit ($45-$75). Wellworth and other value-tier Kohler use standard 3-inch flush valve compatible with universal Korky 2032BP.

TOTO (proprietary throughout)

TOTO uses Tornado Flush + CeFiONtect glaze + TOTO-specific mounting patterns. Aftermarket Korky/Fluidmaster parts do NOT fit TOTO toilets. Service requires TOTO OEM parts through Ferguson, Winsupply, Hajoca, or TOTO USA customer service.

Niagara (vacuum-assist trapway)

Standard universal parts work on Niagara bowls — flapper Korky 2032BP, fill valve Fluidmaster 400A, etc. The vacuum-assist trapway is integrated into the bowl casting (not a serviceable component).

Saniflo (macerator/upflush)

Macerator pump is Saniflo-proprietary and requires authorized service center. Bowl + tank use universal aftermarket parts.

When to call a plumber vs DIY

  • Wax ring failure with subfloor damage: $300-$800 plumber service
  • Recurring drainline clogs: downstream issue requiring snake or video inspection, $150-$400
  • Floor flange replacement: typically requires opening floor, $250-$600
  • Cracked tank or bowl: full toilet replacement (warranty if eligible)
  • Saniflo macerator internal repair: authorized service center only
  • Kohler AquaPiston canister: Kohler customer service may be needed for warranty
  • TOTO proprietary parts unavailable locally: TOTO customer service or Ferguson special-order