Slow drain? What's worth trying and what to skip

Most slow drains are clogged within a foot or two of the opening, usually by hair in a bathroom or grease and food scraps in a kitchen. Start by pulling and cleaning the stopper, then try a plastic hair tool or a plunger. If that doesn’t do it, clean out the trap under the sink or run a small hand auger. Skip the chemical drain cleaner.

Start with the stopper and a hair tool

In a bathroom sink, the pop-up stopper is the first suspect. Hair wraps around the bottom of it and catches soap scum until the whole thing is a gray mat. Some stoppers lift straight out. Others twist out. On a lot of sinks you have to reach underneath and loosen the nut on the back of the drainpipe that holds the pivot rod, pull the rod back a little, and then the stopper comes free.

Clean it off and put it back. Plenty of “clogs” end right there.

Tubs are similar. A toe-touch stopper usually unscrews. If your tub has a lever on the overflow plate, take out the two screws and the whole linkage pulls out through the opening. It’s often wrapped in hair too.

If the stopper’s clean and it’s still slow, get a plastic hair clog tool from the hardware store. It’s a thin strip with little barbs along the edges. Push it down the drain, twist, and pull it back out slowly. What comes up will be gross. That’s how you know it worked. Repeat until it comes up clean, then run hot tap water for a minute.

How to plunge a sink or tub

Use the right plunger. A flat cup plunger is for sinks and tubs. The one with the extra rubber flange on the bottom is for toilets. You can fold the flange up and use it on a sink, but a cup plunger seals better on a flat surface.

1. Stuff a wet rag into the overflow hole and hold it there. On a double kitchen sink, plug the other drain too. Otherwise you’re just pushing air out the other opening.
2. Leave an inch or two of water in the basin so the plunger moves water instead of air.
3. Seat the cup over the drain and give it 10 to 15 firm, straight pumps without breaking the seal.
4. Pull it off sharply and watch the water. If it starts to drop, go another round or two.

Is boiling water safe to pour down a drain?

Sometimes. On a kitchen sink with metal drain pipe, a kettle of boiling water can help soften a grease clog. But most homes built in the last few decades have PVC drains, and boiling water can soften PVC joints. It can also crack a porcelain toilet bowl.

For plastic pipe, and for anything involving a toilet, use the hottest water your tap will give you. It’s safer, and it does most of the same work.

Cleaning the P-trap, then a hand auger

If plunging didn’t work on a sink, the clog is probably sitting in the P-trap. That’s the U-shaped bend in the pipe under the sink, and catching stuff is its whole job.

1. Set a bucket under the trap and keep an old towel handy.
2. Loosen the slip nuts on both ends of the U. Plastic ones usually turn by hand. Use pliers if they’re stuck, but go easy.
3. Drop the trap into the bucket and clean it out. Check the short pipe going into the wall as far as you can reach.
4. Put it back with the washers facing the way they came off. Hand-tighten, run water, and check for drips.

If the trap was clean and the sink’s still slow, the clog is further down in the wall. A small drum auger, the hand-crank kind with a thin cable, can reach it. Feed it in through the trap opening, crank until you feel it catch, and pull it back. It takes a little feel. Don’t force it around tight bends or you’ll kink the cable.

For a toilet, use a toilet auger instead. It has a rubber sleeve on the bend so it won’t scratch the bowl.

What to skip

Skip the chemical drain cleaners. They’re hard on pipes, especially older metal drains, and a lot of the time they just eat a small channel through the clog, which closes right back up. And if they don’t work, you’ve got a sink full of caustic water. Plunge it and that water can splash in your face. Pull the trap and it pours on your hands.

Already poured something in? Don’t plunge it, and don’t add a second product on top of the first. Mixing drain cleaners with each other or with bleach can create dangerous fumes. If you call a plumber, tell them what you used and when.

Baking soda and vinegar won’t hurt anything. It fizzes, which is satisfying, but it doesn’t do much to a real hair clog. A hair tool and hot water will beat it every time.

What if more than one drain is slow?

If the tub and the toilet are both slow, or the shower gurgles when the washer drains, the problem is probably further down the line, in a branch pipe or the main sewer line. Plunging the bathroom sink won’t touch that. Here’s how to tell if your main sewer line is clogged.

If it’s one drain, you’ve cleaned the trap and run an auger, and it still drains slow, give us a call.