What it usually means
The first question is whether it is this toilet or the house. If only one toilet clogs and every other drain is fine, the problem is in the toilet or the short pipe under it. If other drains are slow or gurgle when you flush, the problem is further down.
| Something lodged in the trap | A toy, a toothbrush, a deodorant cap or a wad of wipes sits in the bend and catches paper. It clears when plunged, then blocks again within days. |
|---|---|
| Wipes and thick paper | Wipes sold as flushable do not break down the way toilet paper does. In an older or low-flow toilet they pile up at the first bend. |
| A weak flush | Low water in the tank, a worn flapper or mineral build-up in the rim holes means the bowl never gets the full push it needs. |
| An early low-flow toilet | Some first-generation low-flow toilets from the 1990s simply do not move solids well. Replacement is the real fix. |
| A blocked vent | If the roof vent is blocked the flush is slow and the bowl bubbles. Other fixtures on the same stack usually gurgle too. |
| The sewer line | If the lowest toilet in the house is the one that clogs, and the tub or floor drain backs up with it, the main line is restricted. See sewage backing up in the basement. |
What to check yourself
- Lift the tank lid. The water should sit about an inch below the top of the overflow tube. If it is low, adjust the float.
- Flush and watch. A strong flush empties the bowl in one swirl. A lazy one that rises first and drains slowly points to a partial blockage or a blocked vent.
- Use a flange plunger, the kind with the extra sleeve on the bottom, and give it ten firm strokes with the bowl half full.
- Run the bathroom sink and tub while someone watches the toilet. Bubbles in the bowl mean the problem is in the shared drain or the vent, not the toilet.
- Do not use chemical drain cleaner in a toilet. It sits in the bowl, it can crack the porcelain with heat, and it splashes back when plunged. Why plumbers say no.
Stop and call a plumber if
- Water rises to the rim when you flush
- A second fixture backs up at the same time
- You can hear gurgling in the tub or shower when the toilet flushes
- It has blocked three times in a month
Call 1-800-604-0631, any hour.
What fixing it costs
Clearing a single clogged toilet is a flat price with us: from $269. We run a toilet auger through the trap and, if something is lodged, lift the toilet to get it out. What a toilet clog costs and why.
If the cause turns out to be the main line, that is a different job with a different price, from $649, and we tell you before we start it. Those are regular-hours prices (9 to 5, Monday to Friday). Outside those hours every price is double. Each covers up to 2 hours on site, and the drain is tested in front of you before we leave.
Questions people ask
Can a toilet be too old to flush properly?
Yes. Some early low-flow toilets never worked well, and decades of mineral build-up in the rim and jet weaken any toilet. If the trap is clear and the line is clear, a new toilet is usually cheaper than a third call-out. See toilet installation.
Are flushable wipes really a problem?
They are the most common thing we pull out of a toilet. They go down the bowl but do not break apart in the pipe, so they snag on the first rough joint and collect paper behind them.
Why does it only clog with one person in the house?
Usually the amount of paper per flush. Flushing once part-way through fixes it more often than people expect.