The drain in your bathtub closes to allow you to hold water in the tub, such as for a bath or washing clothes. The problem arises when you have a bathtub drain that refuses to close. You can fix the two main types of bathtub drains — the plunger type and the lift-and-turn type — yourself.
Note that disassembling the plunger type is required in order to service the parts inside. A tool called a bathtub drain removal tool will help you service the lift and turn type.
Fixing Plunger-Type Bathtub Drains
First, loosen the screws holding the overflow assembly in place. This is the metal plate on the side of the tub located just underneath the bathtub spout. Pull the overflow assembly cover out of the tub. There will be a link leading down to the plug in a fully functional drain of this type, and you'll need to reach inside the overflow tube and feel around with your fingers for the link if you do not see it attached.
Pull the plug and link out of the overflow opening. Clean off both the plug and link with a toothbrush to clear away any built up sediment or calcium deposits that could be jamming them and preventing them from plugging the drain properly. Inspect the link connecting the plug to the overflow plate and replace this link assembly if needed.
Next, coat the plug with silicone grease. Apply a few drops of grease to the lever assembly on the back of the overflow tube. Insert the plug into the overflow assembly, replace the overflow plate, and secure it with the screws.
Fixing Lift-and-Turn Bathtub Drains
To fix a lift-and-turn bathtub drain that won't stay open to drain, you'll need to completely remove the stopper from the drain. Start by lifting the drain in the open position. Hold it in place by gripping the larger part of the drain with one pair of pliers, and grab the metal handle on top with the other pair of pliers. Turn the smaller handle counter-clockwise while holding the larger part of the drain steady with your other hand.
Lift the large part of the drain off of the lift rod and examine the pull rod assembly. Extend it to the open position and clean it off with a toothbrush. Apply silicone grease to the rod. Lift it up and down several times to ensure that it is opening correctly. If the rod mechanism no longer functions, you'll need to replace the flange assembly.
Replacing the Flange Assembly
To remove the old flange assembly (also called a "drain basket" or "drain body," according to Plumbing Supply), you may need to rent a device called a drain removal tool from your local hardware store. Otherwise, try to turn it counter-clockwise to remove it.
Roll out a bead of plumber's tape. Press this into place around the underside lip of a new drain and stopper assembly. Insert the new flange into place in the tub. Tighten it by turning it clockwise as you press down firmly.
Extend the center rod to the upright position by pulling it up. Place the large portion of the drain over the rod. Thread the handle into the top of the rod and screw into place clockwise. The drain should now stay open.
Nathan McGinty started writing in 1995. He has a Bachelor of Science in communications from the University of Texas at Austin and a Master of Arts in international journalism from City University, London. He has worked in the technology industry for more than 20 years, in positions ranging from tech support to marketing.