How do I love to unclog a bathtub, let me count the ways…Yep, seven seems to be the magic number. (If you can think of more of them, please feel free to enlighten us.) In my experience, bathtub drains usually don't clog completely. They gradually slow down, day after day, until it gets to a trickle. You know you really have to do something when you're taking shower but your feet and ankles seem to be taking a bath.
1. Coat hanger
Grab a wire coat hanger and a pair of pliers. Cut off the hook and the twisted part, then straighten the wire (you might leave one bend in it for and "handle"). Make a small hook at one end and you've got yourself a free hair-clog grabber. Slip it into the drain hole (which usually has some kind of strainer basket necessitating a small hook on the wire; or remove the strainer if you can), and see what you can pull out. If you have a pop-up-type stopper, you might be able to pull out the stopper for better access to the drain. Tips: Do this before breakfast and before taking a shower; when you see what comes out of the drain, you'll know why. Be careful not to yank on the wire if it gets stuck; you don’t want to damage any stopper parts inside the drain.
This is a "better mousetrap" version of the coat hanger. It's a flexible plastic tool with a handle on one end and a long strip with tiny barbs running down both sides. You insert the strip down the drain, then pull it back out. The barbs catch hair and everything the hair has caught. Every household with long-haired occupants should have one of these inexpensive tools stashed under the bathroom sink.
You might feel that the plunger is to plumbing what blood-letting was to Medieval medicine: It almost never helps, but every once in a while it actually works, so you might as well try it (and it's often effective with toilets). For a tub drain, you want a standard plunger. If you have a toilet plunger—the kind with a narrow sleeve under the larger cup portion—fold the sleeve inside the cup so it's the lip of the cup that makes contact with the bathtub surface. Add a little bit of water to the tub if it's drained dry. Cover the opening of the overflow drain (the round, metal plate on the wall of the tub above the drain) with a rag so no air can get through it and break the suction. Fit the plunger cup over the drain so the lip seals against the tub surface, and plunge away. Remember, it's the suction that does the job, so keep pressure on the cup at all times to maintain its seal against the tub surface.
4. Liquid drain cleaner
No explanation needed. I'm not a big fan of this stuff, but lots of people like to use it. I can certainly see the appeal of pouring in some liquid, heading out to the office for the day, then coming home at night to find a cleared drain. Whether this method works or not, be sure to clean the tub thoroughly before using it. DIY plumbers in Chicago face a small hassle of signing a log and showing photo identification when buying industrial-strength drain cleaners and other noxious substances due to a new law aimed at reducing crime. (Feel free to comment about how you feel about that law.) You could also try making a non-toxic DIY drain cleaner.
5. Drain snake
A simple 25-foot snake will very likely get to the clog, if necessary. Usually you have to snake a tub drain through the overflow pipe: Remove the screws of the overflow plate and carefully pull it up and out; the linkage assembly for the drain stopper is likely to come with the plate, and that's good. Feed the snake down the overflow opening to begin snaking. Remember that there's a P-trap right under the tub. The clog might be in there, but otherwise you have to work the snake past the trap to get into the drainpipe beyond.
6. Disassemble the drain parts
This is a viable option only if you have easy access to the tub drain's P-trap (or a nearby cleanout or removable pipe fitting) from the area below the bathroom, and it's worth considering only if the drain is still slow after you clean it out from the bathtub side of things. Tub drainpipes can get choked with soap residue and other gunk that builds up on the walls of the pipe, especially if it's old cast iron. In my 1951 house, I periodically have to open up the tub drain from below and snake the horizontal run of pipe from the tub to the main waste stack (main house drain). After I scrape out the pipe with the snake, I blast it clean with a garden hose and nozzle.
7. Clean the main drain
This method made the list because sometimes it's not the tub drain that's clogged but rather the main drain or sewer line. And with the high volume of water used in a tub, this is often where you first notice a problem. If, for example, you hear gurgling from the tub when the toilet is flushed or the sink faucet runs for a while, there's a good chance the main drain is clogged. It's time to call a plumber or, if you're up for a really good time, auger the line yourself. Bear in mind that if you unclog the main drain or sewer line and the tub drain is still slower than normal, it's could be that the main clog has led to buildup in the tub drain, so you might have to snake it anyway.