What can I check before I call?

One fixture slow is that fixture. Stop running water if the lowest drain is backing up. Skip the chemical drain cleaner. If there is a cleanout cap outside or in the basement floor, note where it is.

Common problems, answered › Drain backing up

Full Swing · Greater Boston, MA

Drain backing up?

Why does my drain keep backing up? Here is the honest version: what you can safely check yourself in the next five minutes, what a technician usually finds when it is not that, and exactly what it costs to find out.

By Full Swing Plumbing Heating & Cooling, Greater Boston, MA. Updated September 27, 2026. Rated 4.9 out of 5 across 874 reviews.

Check these first

One fixture slow is that fixture. Every fixture slow, or water coming up in the lowest drain when you run water upstairs, is the main line.
Stop running water if the lowest drain is backing up. Every gallon you send down is a gallon in the basement.
Skip the chemical drain cleaner. It sits in the standing water, and the technician has to work in it.
If there is a cleanout cap outside or in the basement floor, note where it is. It cuts the visit in half.

If one of these fixes it, you owe us nothing and we are glad. If not, the next part is what the visit is for.

What a technician usually finds

Main line stoppage. A main that backs up has something in it, and the only way to know whether it is grease, roots, a belly or a broken pipe is to put a camera down it after it is clear. A line with no cleanout is cleared through a toilet or a roof vent every time, which is why the same house keeps paying for access it does not have.

Fixture stoppage. One fixture backing up is a blockage in its branch, and a camera after the clearing shows whether it was a one-time plug or a pipe that has narrowed for good. A branch cleared through a trap arm every year wants a cleanout tee, so the next time is a cap, not a pulled fixture.

Toilet stoppage. A toilet that clogs once is usually something in the trapway the auger pulls out. One that keeps clogging has a line behind it that is narrowing, and a camera after the clearing shows which. A branch cleared through a toilet every time wants its own access, so the next time is a cap, not a pulled toilet.

These are the causes in the manufacturers' troubleshooting charts and the trade handbooks our technicians train on, in plain words. The visit proves which one it is with a meter before anything is replaced.

What keeps it from coming back

Grease and paper build back on the pipe wall; a monthly enzyme treatment eats what a cable only cuts through.

Grease and soap build back on the pipe wall; a monthly enzyme treatment eats what a cable only cuts through.

What it costs to find out

$59 on weekdays, $159 evenings and weekends. Published and final, pre-tax, and the price is the price whether we find a loose wire or a bad motor.

Book the $59 visit online Or call (781) 424-0700

Real arrival windows, including evenings and weekends. Paying is what confirms the slot; the office calls to confirm the window.

Full Swing Plumbing Heating & Cooling · 77 Accord Park Dr B6, Norwell, MA 02061 · (781) 424-0700
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