Bathtub Drain Not Lining Up [2 Easy Fixes]

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You’re installing a new bathtub in your washroom. After installation, you notice that the drain is not lining up. The new drain is not in the same place as the existing drain.  This must be worrying you. 

What to do when your bathtub drain isn’t lining up?

There are mainly two ways to fix this issue. The first is, fitting a coupler or an adapter at an angle. The second option is redoing the fittings underneath the base of the tub. Then using wood shims to level the base. If you’re hesitant, call a plumber and ask him to help you out.

This is just a summary of the solutions. We’ve gone into detail in our article below. 

Interested in knowing the whole process? Just scroll down!

Why Doesn’t My Bathroom Drain Line Up?

There are very few reasons why this can happen. The most common reason is that you live in a very old house. The drain line of old houses and modern houses don’t really match. 

To match the drain line for modern houses, modern tubs are also built that way. When you change the old bathtub and install a new one, the drains don’t line up.

Another time this can happen is when you change the whole system. Like, you were using bathtubs before, and now you’ve installed a shower. Or, you were using a shower before, and now you’ve installed a bathtub. 

Bathtubs and shower tubs don’t usually have the same drain line location. When you change systems, it can be problematic to line up the drain lines. And when drain lines don’t align, low-profile shower trays can overflow.

There’s one other reason, but the chance of this happening is extremely rare. It’s the movement of fittings under the tub. It can be caused by decay or it can happen when they contract excessive force.

The movement of fittings below the tubs can cause the drain lines to shift. It can sometimes cause the tubs to slightly shift in a random direction. And that could cause the drain line to fall out of line.

This is about all the possibilities. Now, let’s fix this issue.

How To Fix Bathtub Drain Not Lining Up? 2 Ways

There are mainly 2 ways to fix a bathtub drain not lining up. The first process is very simple and not time-consuming at all. It’ll probably take you a few minutes to get it done.

But the other process is a lengthy one. It’ll require a lot of work to get it fixed. Since it’s a lengthy process, we’ll be covering it in a different section. It’ll be easier for you to understand that way.

Without further ado, let’s get into the solutions.

Method 1 of 2: Installing A Coupler or An Adapter

This is a very easy method. But, you can’t utilize this method if the drains are more than an inch apart. If they’re apart by an inch or so, only then can you use a coupler.

All you need is a coupler or an adapter for this method. The size of the coupler depends on the size of your drain. If it’s a 1.5-inch drain hole, then get a 1.5-inch coupler. Basically, the size of the coupler needs to match that of the drain line.

You can change a 2-inch to a 1.5-inch shower drain if you want a smaller one. They’re more convenient after all.

Now, you have to place the coupler at an angle. This will allow the water to flow directly inside the drain. Take off the drain cover and insert the coupler. Place it at an angle and all the water will go directly down the drain.

Now you know how to install a coupler or an adapter on a bathtub drain. Let’s not waste any more time and get to the other method.

Method 2: Changing The Fittings Underneath The Bathtub

This method is viable only when the first method fails. By when it fails, we mean when the drains are more than an inch apart. Then you should use this method. Before we get into this method, choose a drain gasket or putty for your tub.

You can go about two ways regarding changing the fittings. The first is, you can apply floor leveling compounds around the area. Spread it around a foot from the opening on the tub and you’ll be good to go.

Here’s a list of some of the best floor leveling compounds you can use-

Product 1
Product 2

The other method requires you to have cut cement boards. They’re sold in sheets just like drywall in the market. This use of a cut cement board will help you level the area. You’ll even be able to seal the area under the frame to avoid any leaks.

Lower the tub base onto the frame and check if the drain lines line up. If they don’t, take some wood shims or plastic shims and use them to balance the base. Screw these shims directly to the floor. 

Next, install new rubber seal gaskets for the drain. Caulk the joints at the base with silicone caulk. And finally, if you have any other plumbing connections to make, do them and you’ll be done.

This is everything on changing the fittings. It’s a pretty easy job so you should be able to do it by yourself.


Question: Should my tub drain have standing water?

Answer: If you have standing water, then unclog the bathroom as soon as possible. They can give rise to diseases.

Question: Can I pour boiling hot water into the drain?

Answer: No, you definitely shouldn’t do it at all. Boiling hot water can harm PVC pipes. There are different pipes for running hot water. And drain pipes aren’t like them.

Question: Do bathtubs come with an overflow system in them?

Answer: Yes they do. It is to keep the bathtub water from overflowing. They’re usually located just a few inches below the rim.


After reading this article, you should be able to fix the bathroom drain not lining up. We hope you’ll follow our instructions properly.

If you get stuck or face any issue, call a plumber to your rescue. 

Good Luck!

Richard Allen