Guide to Installing Baseboard Heater Corner Covers

You probably already know that installing Baseboarders® is a snap. But what about installing a new cover in a corner? Here’s a few questions to ask that will help you get ready then install new baseboard heater covers in a corner.

 Picture of all the different types of endcaps for corners.

What Type of Baseboard Heater Corner Do You Have?

Half the battle is knowing what type of corner you have and getting the right components to suit that specific corner.

90° or 135°?

Corners, in most instances, are either 90 degrees or 135 degrees with the vast majority of those being 90 degrees. A 90-degree corner is the right angle l-shaped corner that you’ll find throughout homes and offices. It’s standard and is easy to work with.

You’ll find 135-degree corners in specialty areas like a bay window or other architectural elements that have larger angles for decorative purposes.

Inside or Outside Corner?

Inside corners meet at an angle that points away from the room. A square room has four inside angles with the vertices forming the corners of the room. Outside corners jut into (or point into) the room.

Knowing whether you have inside or outside corners will help you select the correct couplers or endcaps to complete your installation with finesse.

Get More About Corners


Large room with white walls and a baseboard heater installed in the corner.

How Do I Measure for Baseboard Heater Corner Covers?

A corner installation is basically just two straight lengths that meet together in a corner. The tricky part is ensuring you have the right measurements so that everything fits together correctly.

Inside Corners 90° or 135°

For inside corners, measure the first side from the beginning of the pipe on the far end all the way to wall in the corner. Repeat this process to measure the second side.

Next, subtract 3 inches from both measurements. This will allow the pieces to meet as close as possible in the corner without touching. It will also allow the 90-degree inside corner coupler to cover the cut sides of the panel with ease.

Each of the panels that meet in the corner must both have 3-inch clearance or the corner piece will not fit properly.

Outside Corners 90° or 135°

For outside corners, measure to the point where the two walls meet at the outside corner. There is no need to add or subtract any length because the panels will not interfere with one another and the outside corner piece will extend beyond the end of both panels.

*Please note that outside corners are only available for our Premium and Premium Tall styles.

White walls with white baseboard heater that has an inside corner.

Which Style Should I Get for Corners?

Baseboarders® offers four unique styles: Basic, Elliptus, Premium, and Premium Tall. Each is equipped to handle corner installations. Just be sure you select the right corner components (couples, endcaps, etc.) to fit the panels.

Simply order corner components in the same styles as your panels (Basic, Elliptus, Premium, Premium Tall) and you’re set.

Shop Styles


Illustration of baseboard heater with two 135 degree outside corners.

How Do I Install Baseboard Heater Corner Covers?

With the right length panels and the correct couplers and endcaps, you’re ready for the easiest installation you’ve ever seen. There’s just one more question to ask yourself.

Do You Have a Backplate?

The backplate is a sheet of metal screwed to the wall behind the heating unit. It’s part of the housing for the pipes and fins and it can be difficult to remove. Baseboarders® is designed to work with your existing backplate so it doesn’t have to be removed. This cuts back on many hours of labor and decreases the cost significantly for cover replacement.

If you do not have a backplate, you will need to purchase wall brackets for the new covers to sit on. Wall brackets are sold separately and are available in coordinating colors to our panels and accessories for seamless style.

Get the Guide to Backplates & Brackets 

Ready to Install?

Remove old endcaps and panels leaving the backplate attached to the wall. If you don’t have a backplate, install the wall brackets by measuring, leveling, then screwing them to the wall.

Next apply the endcap to the non-corner edge then slide it onto the existing backplate (or wall brackets). Repeat with the opposite side.

Lastly, apply the corner component on the outside corner to cover the exposed panel ends. That’s it! You’re done!

If you run into any questions or issues, visit our FAQs page, installation page, or talk to us directly. You can reach us online via chat, email us, or give our customer service department a call at 1-844-801-6429.

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