Standing Water Where the Toilet Was: What It Means

You lift the toilet off the floor, and there it is: water sitting in the pipe below. It can be a little at the very bottom, or it can reach up toward the opening. People who find this stop and wonder whether they have broken something, or whether the drain is blocked, and that is a sensible reaction. The answer depends on how high the water is, whether it moves, and what else in the house is draining slowly.

The parts under a toilet, in plain words

When you remove a toilet, you can see a few things:

• The closet flange is the ring fixed to the floor, with slots for the bolts. It holds the toilet and connects it to the drain.
• The closet bend is the curved pipe fitting just below the flange. It turns the vertical drop under the toilet into the horizontal line that carries waste away. Plumbers also call the whole connection the toilet drain.
• The drain line continues from the bend to the main sewer line, or into a stack in a multi-story building.

A toilet has its own trap molded into the base, which is the S-shaped passage that holds water in the bowl. That is why a toilet holds a pool of water while the drain below it should not be holding a pool of its own. Water in the pipe under the floor is not part of the design.

Is it normal?

It depends on how much, and how it behaves.

If you cannot tell, treat it as a blockage. Setting a toilet on top of a partly blocked line means the first flush may not drain.

What to do right now

1. Stop using the bathroom. Do not flush, and do not run the shower, tub or sink in that bathroom, because those drain through the same line.
2. Cover the opening. A rag stuffed gently into the flange, or a toilet-flange plug, keeps sewer gas out. Do not push anything down into the pipe, and do not drop a rag where it can wedge in the bend.
3. Look at the other drains. Run a little water in a sink or a tub elsewhere in the house and see if it drains normally. Watch the water level in the opening while you do. If it rises, the line is backing up.
4. Check for a vent problem. Gurgling from other drains, or bubbles in the pipe when water runs elsewhere, can point to a venting problem as well as a blockage.
5. Make a note. How high the water is, whether it moves, what else is slow, and how long it has been happening are exactly what a plumber needs to hear.
6. Hold off on the toilet. Do not set it back until you know why the water is there.

Common causes

• A blockage in the toilet drain or the branch line, such as paper, wipes, or something that has gone down and lodged. Wipes sold as flushable are a common cause.
• A blockage in the main line, which backs water up into the lowest opening in the house. If it is the lowest toilet, that is often where it appears first. Our guide to main line drain cleaning describes what that looks like.
• Tree roots or a damaged section of pipe, especially in older homes. A camera shows this, and we describe what it finds in what a sewer camera inspection shows.
• A belly or sag in the line, where water collects instead of flowing away.
• A shared stack in a building, where a blockage lower down can back water up into a unit. In that case it is not only your drain.
• A venting problem, where the pipe cannot get air, so water drains slowly or hangs.

A note for condos and apartments

If you live above the ground floor of a building, the drain below your toilet is usually part of a shared vertical stack. A blockage in the stack, or a backup affecting a lower unit, can show up as standing water in yours. Do not flush, and tell building management or the engineer at once, because other residents may be affected, and the building may have its own plumber or rules about who works on the stack. A plumber can still check your branch line and tell you whether the problem is inside your unit or in the common pipe.

What to check before the toilet goes back

Once the water is explained and the line drains properly, a few things need attention before you set the toilet back on the floor:

• The flange. It should be solid, level, not cracked or corroded, and sit on top of the finished floor, not below it. A cracked or rusted flange can be repaired with a repair ring or replaced.
• A new seal. Use a new wax ring or a modern wax-free seal every time a toilet comes off. Reusing the old one is a common cause of leaks.
• Bolts and fit. Use new closet bolts if they are corroded, and tighten the nuts evenly. Overtightening can crack the porcelain.
• A test. Flush several times and look at the base and the floor, and the ceiling below if there is one.

Our step-by-step guide on how to remove a toilet walks through the removal and the signs that mean you should stop and call. If the toilet rocks after it is set back, see why a toilet rocks when you sit.

When to call a plumber

Call if:

• the water is high, rising or coming back,
• other fixtures are slow or gurgling,
• there is a strong sewer smell, or dirty water with debris,
• the flange is damaged or below the floor,
• you cannot clear it or are unsure what you are looking at, or
• it is a shared stack in a building.

A licensed plumber can check the line with a camera, clear it, and tell you whether the problem is a one-time blockage or a sign of something to repair. See our pages on toilet repair and overflowing toilets for the repairs we handle.

Royal Flush Affordable Plumbing is licensed and insured. For toilet removal and reset it works under Texas Responsible Master Plumber License RMPL #42403. The price is agreed before the work begins.

Royal Flush Affordable Plumbing

Licensed Houston plumbers since 2007. Residential, commercial and industrial plumbing. Upfront pricing, no hidden charges.