Unclog a Tub Drain
If you're in standing water when taking a shower, the water is draining too slowly from your tub. Unlike a toilet, which usually is either clogged or not, a tub will gradually begin to drain more slowly as a hair clog builds up. The good news is that the clog usually is just inches away, wrapped around the drain mechanism, which is easily removed for cleaning. Occasionally, a neglected clog travels down the drain line and needs to be snaked out through the overflow drain opening.
There are two basic types of drain assemblies: plunger and pop-up. A plunger system will have a grate over the drain opening and an internal plunger that closes the drain. A pop-up drain has a drain stopper in the drain opening. An improperly adjusted stopper or plunger is also a possible cause of sluggish draining. Modern tub drain systems have an in-line trap designed to prevent sewer gas from entering through the tub drain. Older homes may have a separate drum trap in the floor (usually in an adjacent closet), which can be opened for cleaning and snaking lines. Whatever setup you have, clearing the clog takes only a few minutes using basic tools.
Before You Begin: This job takes only a short time once you gather the necessary tools and supplies (see below). If you have a stopper in the drain, remove it to see if that solves the problem. If it doesn't, or if you have a plunger-type system, fill a large pot with water and bring it to a hard boil. Pour the boiling hot water in the tub to free the clog. If that doesn't work, gather up your tools and supplies.
1. Remove Stopper: If you're lucky, the sluggish drain may be caused by the stopper assembly. Raise the trip lever to lift the stopper and remove the stopper assembly. Remove any hair caught on the rocker arm that is attached to the stopper. Reinsert the assembly with the concave (inward-curving) part of the rocker arm facing the head wall of the tub.
2. Remove Strainer: A clog is rarely caught between the strainer and the vertical portion of the drain assembly, but it's easy to check. Lift the trip lever to close the drain. Remove the strainer with a screwdriver. Then, bend a hook on the end of a wire (such as a piece of stiff electrical wire); insert it in the drain; and try to locate and fish out any clog or object. You may need long-nose pliers to retrieve the clog once it's visible.
3. Remove Drain Assembly Cover Plate: Two screws (usually Phillips head) secure the cover plate, but before you take them out, cover the drain hole with a cloth to prevent accidentally losing a screw down the drain. Next, unscrew the cover plate being careful not to mar the finish.
4. Lift Out Drain Assembly: Carefully lift out the drain assembly (cover plate, trip lever, striker rod, and, depending on the type of system you have, either a plunger or a striker spring). Remove any hair clogs. Clean the mechanism with an old toothbrush or a soft wire brush and lubricate it with heat-proof grease.
5. Plunge Drain Line: If the tub still drains slowly, you can try to plunge the drain line, especially if you own a plumber's helper (plunger); do not use a hand auger or plumber's snake. In order for the force of the plunger to be directed at the clog and not dissipated up and out the overflow drain, you must first plug the overflow drain opening with a wet rag. Then, put a little water in the tub and plunge away.
6. Auger Drain Line: Using a hand auger works better than a plunger because it pulls the clog out rather than pushing it down the drain. Insert the end of the cable down the overflow drain opening, past the bend at the top of the pipe, until you feel soft resistance. Screw the auger into the clog and try to pull it back out. Run the water to test the drain.
7. Adjust Plunger Linkage: If a cleaned drain is still sluggish, you may need to raise the plunger so it doesn't partially obstruct the drain when in the open position. To do this, unscrew the lock nut on the lift rod. Then screw the rod in about 1/8 inch, retighten the lock nut against the fitting, and test. If the rod is non-threaded, loosen the fastener that secures it and slide it up before re-tightening the fastener.
8. Adjust Pop-up Linkage: If you have a pop-up drain system, you adjust the striker rod, here a non-threaded rod that is secured with a screw. Still other designs involve a non-threaded rod that is secured with locking nuts. Or try to adjust the stopper. Loosen the lock nut and unscrew it slightly. Be careful not unscrew it so much that it won't seal in the closed position.
9. Clear Clogged Drum Trap: If you notice a 3- or 4-inch-diameter metal cover on the floor of your bathroom near the drain end of the tub or in a closet adjacent to it, you have an old-fashioned drum trap. To clean it, twist off the cover using an adjustable wrench, and use a hand auger as described in Step 6 to clear any clogs in the pipes that tie into the trap.
Provided by: http://doityourself.com/drainage/unclogtubdrain.htm