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Replacing a toilet, faucet or sink so it fits.

A homeowner or trained tech can read model marks, measure and prove the stops, and a licensed plumber should replace stops, move rough-in piping, cut into a stack or reset an in-wall valve where local rules require.

Customers put it like this

  • Will this new toilet fit
  • We bought a new faucet and want it installed
  • The new shower valve has hot and cold backwards
  • We are swapping out the old garbage disposal
Prepare this job in ForeBotFind another guide

Stop first if

  • No valve, not even the main, will shut the water off at this fixtureDo not loosen anything. Call a licensed plumber or the water utility to get the water shut off first.
  • Water has reached outlets or a panel, or a wired disposal or bidet seat still has power beside the waterStay out of the water. Shut the breaker only if it can be done without risk. Otherwise call a licensed electrician.
  • The floor around the old fixture is soft or sagging, or framing behind it looks damagedKeep weight off it and hold the swap. Have a qualified person check the floor or framing first.
  • You smell gas near the heater or any appliance on the jobLeave the building now. From outside, call emergency services or the gas utility.
01

Ask on the call

6

Homeowner? These are the questions a good technician will ask you. Having the answers ready makes the first visit count.

  1. What is being replaced or added, and is the new one bought yet, on site, or already installed?
  2. Can you read a brand or model on the old one, or keep the old part?
  3. What is the maker and full model number of the new one, as printed on the box or the maker's sheet?
  4. Can you measure from the finished wall to the toilet bolts or the drain and supply pipes?
  5. Is there a shutoff under the fixture, and does it fully stop the water?
  6. Does this room need to meet accessibility rules, such as grab bars or a required seat height?
02

Bring

5
  • Tape measure
  • Maker's rough-in sheet for the exact model
  • Flashlight and phone camera
  • New supply lines and trap pieces to match
  • Thermometer
03

Check on site

7
  1. Read the maker, full model number with any ending letters, finish and pack size from the box, part or maker's sheet. Never order from a store listing or a look-alike.
  2. Measure from the finished wall to the drain or toilet flange and the supplies. Compare with the maker's rough-in sheet for that exact model, not with the drawings.
  3. Read the connection type and size at each stop outlet and the trap, and match them to the sheet. A new faucet gets new supply lines; a new sink, a new trap.
  4. Close each stop and open the faucet to prove the water is off before loosening a line. If one will not hold, use the main. Later, check each stem for seepage.
  5. Once it is in, run each handle: hot on the left, cold on the right. A tech checks a shower valve's up marking and sets any new mixing valve.
  6. On a disposal swap, with it unplugged or its breaker off, check that the dishwasher inlet plug was knocked out. Then run the dishwasher and watch it drain.
  7. Adding a fixture or cutting into a stack: a licensed plumber checks the drain load and fall against the local code limit.
04

Keep on the record

6
  • Photo of the new item's label showing maker, full model, finish and pack size
  • Photo of the old fixture's marks, or the old part kept
  • Measured rough-in beside the maker's figure for that model
  • Connection type and size at each stop and the trap
  • Whether each stop held and stayed dry at the stem
  • Which side runs hot after install, and the outlet temperature of any new mixing valve

General guidance for a qualified person, not a finding about any home. The person on site decides.