The ten-minute test that decides everything
Before you call anyone, run every drain in the house, one at a time, while somebody watches the fixture that’s backing up. Fill each sink and pull the plug so it empties at full volume, not a trickle. Run the tub and shower, flush every toilet, and if you can, let the washing machine reach its drain cycle — the biggest surge your system ever sees. Watch and listen at the affected fixture and at the lowest drain in the house: a basement floor drain, a laundry standpipe, a ground-floor shower.
Two outcomes, and they are completely different problems.
Only the one fixture is slow, everything else runs normally. The blockage is in the branch line serving that fixture and nowhere else — a local clog of grease, hair, soap, or an object. A plunger, a hand auger, or one routine drain call fixes it, and the rest of this page is about doing that cheaply.
Two or more fixtures affected, or the lowest drain gurgles, bubbles, or fills while you run something else. The blockage is downstream of everything, in your main line or the sewer lateral out to the street. Different diagnosis, different trade, roughly ten times the money. That case has its own sequence, starting with a call to the city rather than a plumber. Other tells: the tub filling when you flush, every drain slowing over the same few weeks, neighbors affected at once, or symptoms only in heavy rain.
Why the lowest drain decides it. Drainage runs on gravity, so water backs up and exits at the lowest opening below the blockage — which is why an upstairs bathroom can look perfectly fine while a basement floor drain overflows. Flush an upstairs toilet and stand next to the lowest drain in the house. Nothing happens, the problem is above it in one branch. It gurgles or rises, the problem is below both.
What a gurgle actually means
A drain system has two halves: drain pipes carrying water down, and vent pipes running up through the roof letting air in behind it. Every fixture holds a plug of water in its trap to block sewer gas from the room.
Falling water pulls a partial vacuum behind itself, and that air has to come from somewhere. With a clear vent it comes from the roof and nobody hears anything. With a blocked vent, or a drain too restricted for water to move past freely, the system takes air through the nearest opening instead — another fixture’s trap. That pull through a water seal is the gurgle, and where it happens is the whole diagnosis:
- At the same fixture you’re using — air struggling past a partial clog in that fixture’s own line. Local, minor.
- At a different fixture — those two share a line and the shared section is restricted. Escalation.
- A toilet bubbling when the washer or a tub drains — the textbook partial main-line blockage, arriving weeks before a real backup.
- Gurgling and slow drains everywhere with no obvious clog — suspect the vent, not the drain. Leaves, a bird’s nest, or ice will close a stack. Fixr puts clearing a blocked plumbing vent at $250 to $500.
Gurgling also siphons water out of traps, which is why it is often followed a day or two later by a sewer smell in the room — a short list of causes, some free to fix.
Diagnosis by fixture
Kitchen sink — grease, and further in than you think. Fats go down as liquid, cool, coat the pipe wall, then catch coffee grounds, rice, and starch until the passage closes. Kitchen clogs typically sit in the horizontal run well past the trap, five to twenty feet in, which is why hot water and dish soap produce a temporary improvement and no fix. Test a garbage disposal separately: Fixr puts a jammed disposal at $60 to $150 against $150 to $500 for the drain behind it. On a double sink, water rising in the second bowl puts the blockage past the tee joining them.
Bathroom sink — hair, soap scum, and the stopper. The most common bathroom sink clog isn’t in the pipe at all. It’s wrapped around the pop-up stopper rod three inches down, and you can pull the stopper and clean it in five minutes for nothing. Failing that, the trap is next — Fixr prices a plumber clearing a P-trap at $100 to $300.
Tub or shower — hair, at the strainer or just past it. A plastic barbed hair tool costs a couple of dollars and clears most of them. If you plunge, block the overflow plate with a wet rag first, or you’re pushing air out of the overflow rather than pressure down the drain.
Toilet — not the same fix, not the same tool. A toilet has its own S-shaped trapway molded into the porcelain, and most toilet clogs sit inside it rather than in the branch line. Use a flange plunger, not the flat cup plunger from under the kitchen sink. Failing that, the tool is a closet auger — a short hand auger sleeved in plastic so the cable can’t scratch the glaze; a standard drain snake will chip a bowl. Fixr puts unclogging a toilet at $200 to $700, national average $350, an auger clearing at $100 to $250, and pulling the toilet off the flange at $200 to $550.
Floor drain or laundry standpipe. Usually the lowest opening in the system, so a backup here is rarely local — go back to the triage test above and assume the main line until proven otherwise.
Why chemical drain cleaner is usually the wrong move
On a fully blocked drain the product never reaches the clog — it sits in the standing water above it, diluting. On a partial clog it works slowly, works only on organic grease, and does nothing at all to a hair mat, a root intrusion, a collapsed section, or a child’s toy. It is caustic and generates heat while it sits: in old cast iron that accelerates corrosion, and in plastic a strong acid cleaner held against one spot for hours can soften the pipe.
The bigger issue is what it does to the next step. That sink of standing water is now a sink of caustic liquid, and it will splash when somebody opens the trap. Say so when you book a plumber, and again before they start.
Enzyme and bacterial products are a different category — slow, non-caustic grease control, a reasonable monthly habit on a kitchen line with a history. They will not open a blocked drain tonight.
Snake, auger, or hydro jet
- Hand auger or drum snake, twenty-five feet. The right tool for sinks, tubs, and most branch lines, and the one that solves most single-fixture clogs. Fixr puts rental at $35 to $80 per day — the cheapest version of this entire page.
- Closet auger. Toilets only, and toilets should only see this one.
- Electric or power snake. Fifty to a hundred feet of driven cable with cutting heads, reaching what a hand auger only pushes. Fixr prices one on a kitchen sink at $250 to $400.
- Hydro jetting. A high-pressure hose that scours the pipe wall instead of punching through the middle of the blockage — the correct tool for baked-on grease and root hair. Fixr puts jetting a kitchen line at $300 to $500. It isn’t right for brittle old pipe, which is why a competent tech cameras it first.
The distinction that matters commercially: a snake makes a hole, a jet cleans the pipe. If the same drain has been snaked three times in a year, you are buying a hole repeatedly.
Who to call, and what it should cost
For a single fixture, in order: plunger and trap yourself, then a hand auger, then a general plumber or a drain cleaning company. A drain and sewer specialist with a camera and a power machine is the right call when the clog repeats or when more than one fixture is involved — and the wrong call, on cost, for a first clog in one sink.
Fixr’s numbers for the routine version: clearing a single clogged drain runs $100 to $500. A kitchen sink is $250 to $400, national average $300 — $100 to $300 with a hand snake, $250 to $400 electric, $300 to $500 jetted, $100 to $300 if it’s just the trap. A toilet runs $200 to $700, average $350. Underneath it all, plumber labor is $75 to $150 an hour, national average $90, plus an initial service call of $50 to $150 for a journeyman or $150 to $300 for a master plumber.
Set that against the other side of the triage line and the ten-minute test justifies itself: Fixr prices clearing a main sewer line clog at $350 to $650, national average $475, tree root removal at $100 to $600, and a full sewer line inspection at $750 to $1,500 — before any repair.
After-hours pricing is where one slow drain gets expensive for no reason. Fixr puts an emergency drain call outside business hours at $450 to $800. If one fixture is out and the rest of the house works, close the door and book a morning slot. What justifies the premium: it’s your only toilet, wastewater is reaching flooring, or a second fixture just joined in.
When a camera inspection is justified — and when it’s an upsell
A camera is not warranted on a first clog in one fixture. It is warranted when the pattern says the pipe itself is the problem: the same drain clogs every three to six months, the clog returns within weeks of a clearing, more than one fixture is involved, or the house is forty-plus years old with clay or cast iron drain lines and mature trees near the lateral.
Fixr prices a drain camera inspection at $200 to $400, or around $650 with line opening included. Against four repeat drain calls a year, that pays for itself. Recurring clogs almost always resolve to roots at a joint, a sag holding standing water, or a broken or offset section.
Be alert at exactly this moment, though. A camera pass on what started as a single-fixture clog, followed same-day by a five-figure quote to replace the whole sewer, is one of the most reliable upsells in the trade. Ask for the video file, not a phone screen in a hallway. Ask for the footage-counter distance to the defect, and why spot repair, lining, or root cutting were ruled out. Then get a second opinion from a company that isn’t quoting the work — what a legitimate diagnosis includes and a pressure sale doesn’t is worth reading before you sign anything the same day.
One cross-check: a clog restricts what leaves the house, not what enters it, so it shouldn’t move your water bill. If the bill jumped in the same period, that’s a separate supply-side hunt.
If you rent
Report it in writing the same day — date, fixture, symptom, plus a photo — before you call anyone yourself. Most leases require notice and a reasonable chance to repair, and a tenant who books their own plumber first has usually just bought the repair.
Who pays turns on cause, which is exactly what gets argued about. Landlords are generally responsible for keeping plumbing in working order, covering clogs arising from the age, design, or condition of the line: root intrusion, a bellied branch, decades of scale. Tenants are commonly charged for clogs they caused — wipes, grease, a toy in the toilet. That’s why whatever the plumber says about the cause belongs in writing on the invoice.
A slow bathroom sink in a two-bathroom unit is a maintenance ticket. A backing-up toilet in a one-bathroom unit is a habitability problem with a much shorter legal clock, and should be reported in those words. If nothing happens, the escalation ladder — notice periods, repair-and-deduct, and the retaliation protections attached to it — is what to have open before the second message.
Keeping that drain clear
- Nothing greasy down the kitchen sink. Not bacon fat, not pan drippings, not the oily water off a roasting tray. Jar it, let it set, bin it.
- No wipes, ever, including the ones sold as flushable. They don’t break down.
- Hair catchers in every tub and shower, and the most common bathroom clog stops happening.
- Cold water while the disposal runs, and twenty seconds after, so fats stay solid and get flushed instead of coating the pipe. Keep stringy and starchy waste out of it.
- Once a month, fill each sink and tub and pull the plug. A full-volume release scours a line the way a running tap never does.
And the seasonal one, because it is the trade’s busiest day of the year: Thanksgiving. Turkey fat down the sink, a disposal fed potato peel and celery, and four extra people showering on one drain line will find whatever weakness that plumbing already had. If a drain has been slow for a month, deal with it the week before rather than the day of, when every drain company is booked out at the after-hours rate.