A drain snake usually fails for one of five reasons: the cable is the wrong size for the pipe, it is fighting a bend it could pass if rotated, it has gone up a vent instead of down the drain, it has reached the clog but only poked a hole, or the blockage is beyond its reach. Rotate through bends and match cable to pipe.
- A cable passes bends by rotating through them, not by being pushed harder; pushing makes it buckle and coil behind the bend.
- Cable that comes back clean and dry probably went up a vent, not down the drain.
- A thin cable in a large pipe spins freely and feels busy while doing nothing.
- A stuck snake is freed by stopping, letting the torque unwind and pulling back while turning forward, never by yanking.
- Some problems that look like clogs, such as a blocked vent or a frozen line, cannot be fixed by any snake.
01 /Why won't the snake go down the drain?
A snake will not go down the drain when something close to the opening is stopping the head before it reaches the pipe: a stopper, crossbars, a tight tailpiece, a trap bend, or a cable too stiff for the fitting. The distance at which it stops tells you which one.
| Stops at about | Likely obstacle | Fix |
|---|---|---|
| A few centimetres | Pop-up stopper, tub crossbars, shower strainer | Remove the stopper or strainer; use the tub overflow instead of the drain |
| 20 to 50 cm | Trap bend | Rotate through it, or remove a sink trap and enter the trap arm |
| About 0.5 to 1.5 m | Sanitary tee where the trap arm meets the drain in the wall | Rotate slowly so the head drops down the tee |
| Cable slides back into the drum | Thumbscrew or chuck not locked | Lock the cable before cranking, with only a hand's width exposed |
| Cable bows out at the opening | Too much cable exposed between drum and drain | Hold the drum close to the opening and shorten the exposed length |
| Will not enter a small trap at all | Cable too heavy for the fitting | Use 1/4-inch cable in 1-1/4 and 1-1/2-inch traps, or bypass the trap |
Sinks and tubs have dedicated techniques that avoid most of these: how to snake a sink enters through the trap arm, and how to snake a bathtub or shower drain uses the overflow. Toilets have their own fit problems, covered in what size toilet auger you need.
02 /How do you get a drain snake around a 90-degree bend?
You get a snake around a 90-degree bend by rotating it as it reaches the bend, with only light forward pressure, so the coiled cable screws itself around the curve. Drain fittings are made as sweeps rather than sharp corners so that water and cable can follow them, but the cable still needs rotation to find the path. Pushing without rotation drives the head into the outside wall of the bend, and the cable behind it buckles.
- Feed until it stops
Push by hand with no rotation until the head meets the bend. Note the distance.
- Pull back a few centimetres
Give the head room to turn instead of pinning it against the fitting.
- Rotate with light pressure
Crank or run the drill slowly clockwise and ease forward. You will feel the head drop or slip around when it finds the curve.
- Keep exposed cable short
With a hand drum, lock the cable no more than about 15 cm from the opening. Loose cable outside the drain absorbs the force you meant for the bend.
- Try a lighter head
A bulb head or a flexible leader steers through bends more easily than a stiff straight coil or a cutter.
- Change the access point
If the bend will not pass after several tries, enter from beyond it: remove a trap, use an overflow, or use a cleanout downstream of the bend.
A cable goes around a bend by turning, not by being pushed.
Very tight turns are usually on the vent side of the system rather than the drain side. If the cable has passed a bend easily and then runs freely upward, it may have entered the vent.
03 /Why does the snake go in but nothing clears?
A snake that goes in easily without clearing the drain has usually gone somewhere other than the clog: up a vent, into a coil inside a large pipe, or down a different branch. Sometimes it did reach the clog but only bored a hole through it.
- It went up the vent. The cable comes back clean, dry or dusty. Pull back to the tee and rotate slowly so the head falls into the downward sweep.
- It is coiling in a larger pipe. A 1/4-inch cable that enters a 3 or 4-inch pipe lies in loops and never pushes against the clog. Step up to the cable size for that pipe; the auger cable size chart and the Auger Cable Sizer give the pairing.
- It only poked a hole. Water drains, then the fixture slows again within days. Grease and packed sludge need a cutter head, several passes, or a different method; see auger cutting heads.
- The clog is in another line. If the cable went into the fixture's branch but the clog is in the shared branch or main, nothing you do from that fixture will clear it. The Clog Locator places the clog from which fixtures are affected.
- The clog is beyond reach. A 25-ft hand drum runs out before a clog in the building drain. The cable coming back clean at full length is the sign.
04 /What should you do when a drain snake gets stuck?
When a drain snake gets stuck, stop rotating, let the twisted cable relax, and then pull back gently while turning forward. Most stuck heads are wrapped in hair or wipes, or caught on the edge of a fitting, and they release when the stored twist is let out rather than when the cable is yanked.
- Stop turning
Stop cranking, or take your foot off the pedal on a powered machine. Keep your hands clear of any loop forming in the cable.
- Let the torque unwind
Allow the cable to spin back on its own until it hangs straight. On a hand drum, loosen the lock and let the drum settle.
- Pull back while turning forward
Draw the cable back slowly while cranking clockwise. This keeps wrapped material on the head and walks the head off an edge.
- Work it in and out
Short back-and-forth movements with gentle rotation free a head hooked on a joint or a trap seam.
- Reverse only briefly, if allowed
A half turn in reverse can release a head caught on an edge. On powered machines, only use reverse as the manufacturer's instructions allow; on sectional machines, reverse can uncouple the cable in the pipe.
- Stop if it will not come
Do not tie it off, pull with a vehicle or run the motor harder. A stretched or broken cable left in a drain can mean opening the pipe to recover it.
05 /Why does the cable keep kinking or twisting?
Cable kinks when it keeps rotating at the handle end while the head is held still, or when it is too thin for the force being put through it. The twist builds up between the drum and the drain until the coil deforms.
- Pushing while the head is stopped. Ease off as soon as you feel the cable load up.
- Drill on high speed. Drill-powered augers need low speed and short bursts; high speed twists 1/4-inch cable in seconds.
- Cable too thin for the pipe. Thin cable in a large pipe has room to spiral.
- Too much exposed cable. Hold the drum close to the opening.
- Tired cable. Cable that has been kinked before kinks again at the same spot. Cut out the damaged length or replace it; cleaning and storing a drain auger covers what to look for.
06 /When is it not the snake's fault?
It is not the snake's fault when the problem is not a clog in the pipe. Several common faults produce slow drains and gurgling with a pipe that is perfectly open, and no amount of cable will change them.
| Problem | What you notice | What does fix it |
|---|---|---|
| Blocked plumbing vent | Slow drains and gurgling in several fixtures; traps lose water; snake finds nothing | Clear the vent; see snaking from the roof vent |
| Frozen line or frost-closed vent | Sudden stoppage during extreme cold with no clog history | Thawing, not cable; see snaking a drain from outside |
| Grease coating the pipe wall | Cable opens it, then it slows again within weeks | Jetting and kitchen habits |
| Fouled backwater valve | Floor drain pattern with a clear pipe | Clean and check the valve |
| Municipal main surcharge | Neighbours affected, often in heavy rain | Call the municipality (in Calgary, 311) |
| Failed ejector pump or full septic tank | Basement fixtures or the whole house stop together | Pump repair or septic service |
If you have worked through these and the drain is still slow, the clog may simply be bigger or further than a household snake can handle. The Auger Cable Sizer shows which machine class the line needs and when to hand it off, and you can request quotes from drain professionals who can add a camera to find out what is really there.
FAQQuestions people ask
Can a drain snake go around an elbow?
Yes. Drain elbows are sweeps, and a cable passes them by rotating as it reaches the bend with light forward pressure. Pushing hard without rotation makes the cable buckle behind the bend.
Why does my drain snake come back clean?
It probably went up the vent instead of down the drain, or it is coiling in a pipe larger than it suits. Clean, dry cable has not been in the drain water.
Can drain snakes get stuck in pipes?
Yes, usually when the head wraps into hair or wipes or catches on a fitting. Stop turning, let the twist unwind and pull back while cranking forward.
Why is my drain still slow after snaking?
The cable may have only bored a small hole in grease or sludge, missed the clog, or the real problem may be a vent. A drain that slows again quickly usually has a cause the cable did not remove.
Should I push harder if the snake stops?
No. Pull back slightly and rotate. Extra force makes the cable buckle and kink and can damage fittings.
Why does my snake keep coming back up the sink?
Too much cable is exposed or the head is jammed at the trap bend. Shorten the exposed cable, rotate through the bend, or remove the trap and feed into the trap arm.
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