Free U.S. Shipping & Lifetime Warranty For All Endura Flap Pet Doors

Regular price
$469.99
Sale price
$469.99
Unit price
per 

Endura Flap Thermo Panel 3e

Regular price
$469.99
Sale price
$469.99
Unit price
per 
White
Dark Bronze/Black
Brushed Aluminum

  • Aluminum framed, insulated dog door for sliding glass doors with widths from 11 1/4" to 17 1/4" inches
  • Enhances energy efficiency construction
  • Adjustable heights and custom sizes for the perfect fit
  • Easy, semi-permanent installation perfect for renters or vacation homes
  • Secure steel-grade locking cover for added safety and control
  • Prefer dual pane glass? Explore our Dual Pane Thermo Panel

Custom Order | Ships in 3-5 Weeks | Non-Returnable

Superior Weather Resistance Superior Weather Resistance
Great for Renters Great for Renters
Easy Installation Easy Installation

Product Details

  • Premium pet door solution: The Endura Flap Thermo Panel 3e is designed for sliding glass doors and offers a convenient way to grant your pets the freedom they desire
  • Easy installation and removal: With a removable panel and spring-loaded top, this pet door is perfect for rental properties or vacation homes
  • Energy efficiency: The polyolefin polymer flap withstands temperatures as low as -40°F and includes magnetic closure on three sides for enhanced weather resistance. Comes with 3/16" clear safety glass, which is 59% thicker than the standard for enhanced durability and increased energy efficiency
  • Customizable to fit your home: Adjustable heights and custom sizes accommodate a variety of sliding glass door models with tracks at least 1" thick; available in white, black, and brushed aluminum to match your interior design
  • Secure and sturdy: The Thermo Panel 3e includes a heavy-duty molded ABS locking cover and C-Clamp Lock to provide added security when needed
  • Highly-rated by pet lovers: Many have praised the Thermo Panel 3e's easy installation, exceptional insulation, and durable construction, giving their pets the freedom to come and go as they please
  • Lifetime warranty and US-based customer support: Enjoy peace of mind with a lifetime warranty and dedicated customer support for your Endura Flap Thermo Panel 3e doggy door for sliding door 
  • Customize for your pet's comfort: Adjustable step over height allows you to tailor the patio pet door panel to your pet's size so that they may comfortably use the pet door
  • For a dual-pane glass option, see the Endura Dual Pane Thermo Panel 3e (also available with custom height ranges)

Size Chart

Flap Dimensions:

6"w x 11"h

The entry way your dog goes through.

Overall Panel Width

10 3/16"

How wide your panel is.
flap dimensions
epanel width
step over height

Step-Over Height

3" - 4-1/2"

The distance from the bottom of the panel to the bottom of your flap.

Flap Dimensions:

8"w x 15"h

The entry way your dog goes through.

Overall Panel Width

12 1/4"

How wide your panel is.
flap dimensions
epanel width
step over height

Step-Over Height

3" - 4-1/2"

The distance from the bottom of the panel to the bottom of your flap.

Flap Dimensions:

10"w x 19"h

The entry way your dog goes through.

Overall Panel Width

14 1/4"

How wide your panel is.
flap dimensions
epanel width
step over height

Step-Over Height

3" - 6"

The distance from the bottom of the panel to the bottom of your flap.

Flap Dimensions:

12"w x 23"h

The entry way your dog goes through.

Overall Panel Width

16-3/8"

How wide your panel is.
flap dimensions
epanel width
step over height

Step-Over Height

3" - 6"

The distance from the bottom of the panel to the bottom of your flap.
Flap SizeFlap DimensionStep Over RangeOverall Panel WidthRecommended Pet Height
Small6" w x 11" h3" - 4-1/2" (ships at 3")10-3/16"9" - 15"
Medium8" w x 15" h3" - 4-1/2" (ships at 3")12-1/4"9" - 21"
Large10" w x 19" h3" - 6" (ships at 4-1/2")14-1/4"9" - 27"
Extra Large12" w x 23" h3" - 6" (ships at 4-1/2")16-3/8"9" - 34"

Note: Endura Flap is not recommended for kittens or very small dogs.

 

Important Information about Custom Heights

Custom Height Minimum & Maximum Heights
ModelMinimumMaximum
Small 35"100"
Medium 42"107"
Large 48"117"
Extra Large 46"123"


Custom orders are final sale once built. They are essential in two situations:

While most sliding glass door track heights are in the three standard height ranges offered, some are not. In those cases, we can build a Thermo Panel 3e in a custom height to fit your specific dimension. 

The second situation is when you have a side-sliding window. A sliding window is essentially a miniature sliding glass door, and you can install a custom height panel, provided the window track is at least 1" wide.

Find The Best Pet Door Size For My Pet

calculator.jpg

A

Pet Height: inches

B

Pet Width: inches

Please fill the above fields.

Additional Information

Frame Material

Architectural Extruded Aluminum

Track Width Minimum

1"

Flap Thickness

7/8"

Warranty Period

Lifetime

Return Period

90 days (except for custom sizes)

Locking Cover Material

Heavy-Duty Molded ABS

Climate Suitability

Severe-4 Season

House Locking Method

C-Clamp Lock

Flap Design

Single, Flexible, Insulated Flap

Ability to Lock Flap

Separate Locking Cover-Loads from Top

Can Be Installed In

Dual Pane Glass Sliding Glass Door, Single Pane Glass Sliding Glass Door, Vinyl-Framed Sliding Glass Door, Sideways Sliding Windows

Custom Heights Available

Yes

Sealing Value

Very High

Wind Resistance

Very High

Replacement Flaps Available

Yes

Insulation Value

High

Installation Instructions

One-Piece Panel

Installation icon Printable Version
Installation icon Difficulty Easy
Installation icon Steps 09
Installation icon Time Required 0.5 hours
Installation icon Flags 02

Parts

  • 1 Panel Pet Door
  • 1 Foam Weather Strip
  • 1 Center Post Weather Seal Draft Stopper
  • 1 Sliding Door C-Clamp Lock
  • 1 Flathead Screwdriver

Tools

  • Flathead Screwdriver

Please read instructions & notes thoroughly before installation.


One-Piece Panel

Step 1 Adjust the Step Over (Optional)

  • The Endura aluminum sliding door panel has a patented Adjustable Step-Over feature which allows you to adjust the height of the flap to the most comfortable fit for your pet.
  • Adjusting the step-over requires tools that are not supplied. You will need a Phillips-head screwdriver, and we recommend using a power tool if available, as the screws were tightly installed to hold the panel together during shipping.
  • The top of the flap should be positioned to be at least 1” above the top of the pet's shoulder.
  • If the factory setting is not suitable, please adjust it before proceeding. Otherwise, proceed to the Installation Instructions section.

Step 2 Adjust the Screws

  • Lay the entire panel on a flat surface.
  • Using the Phillips-header screwdriver, or selected power tool, remove the bottom side-screws and loosen the upper side screws.

Step 3 Adjust the Spacers

  • Once the bottom screws have been removed and the upper side-screws loosened, the Pet Door Assembly and spacers can be removed by sliding the sections down and out of the panel.

Step 4 Replace the Spacers

  • Replace the spacers and the Pet Door Assembly by sliding them back in a different order to achieve the desired height. You can move the spacer below and above the flap to raise or lower the flap height.
  • It is critical that the bottom piece is placed at the base. This is the designated attachment point for the screws.
  • Make sure that the locking cover side of the flap frame is on the same side as the height adjustment locks.

Step 5 Tighten the Screws

  • When finished, replace the bottom side-screws and tighten the next upper-side screws.
  • A lower step-over height is easier for pets to navigate. However, if the top of the flap is low enough that the pet needs to crouch to get through their pet door, they can injure themselves and possibly cause the pet door to malfunction. If your pet door does not sit at a comfortable height for your pet, you may need a larger flap size.

Step 6 Unlock Spring Mechanism

  • Loosen the height adjustment locks at the top of the pet panel with the screwdriver. This allows the spring mechanism to move freely up and down.

Step 7 Test Fit the Panel in Your Track

  • You want to put the pet door in your track before applying any weather stripping to ensure it fits. If the panel fits well, proceed to the next step. See the Troubleshooting Section if you encounter difficulties.
  • To insert the panel into the top track, push up against the spring mechanism and swing the bottom of the panel up and over the threshold.
  • Seat the panel on top of the small guide rail in the track.
  • If you can't quite get it in the track, try swinging in from the outside as the outside track wall may be shorter.

Step 8 Apply the Weatherstripping

  • Once you're sure the panel fits, remove it from the frame and lay it on its side on the ground.
  • For foam weatherstripping: Peel the backing off the foam weatherstripping. Press it along both edges of the panel, trimming as needed with scissors to ensure a snug fit.
  • For rubber weatherstripping: Clean the edge of your sliding door or window with rubbing alcohol to help the weatherstripping stick properly. Starting at the top or bottom, peel and press the strip into place with the folded edge facing indoors—align angled cuts if you have two pieces. For best results, apply the seal to the sliding door or window, but it can go on the pet door panel if needed.
  • Foam weatherstripping is applied onto both sides of the panel, but the rubber weather stripping only applies on the side of the slider door. Your panel will come with one type of weather stripping. You do not need both types.

Step 9 Install the Draft Stopper

  • The center post weather seal strip (draft stopper) should be installed on the inside of the home.
  • It can install on either the back edge of the sliding door panel or the leading edge of the stationary panel.
  • This strip prevents air from leaking between the sliding glass door and the stationary panel.
  • Trim with scissors as needed. Clean the edge of your patio door with rubbing alcohol before installing to assure a good seal.
  • Repeat step two to install the panel in your track.

Two-Piece Panel

Installation icon Printable Version
Installation icon Difficulty Easy
Installation icon Steps 11
Installation icon Time Required 0.5 hours
Installation icon Flags 02

Parts

  • 1 Top Glass Panel Section
  • 1 Bottom Flap Section
  • 1 Foam Weather Strip
  • 1 Center Post Weather Seal Draft Stopper
  • 4 Flathead Screws
  • 1 Flathead Screwdriver
  • 1 Sliding Door C-Clamp Lock

Tools

  • Flathead Screwdriver

Please read instructions & notes thoroughly before installation.


Two-Piece Panel

Step 1 Adjust Step Over Height (Optional)

  • The Endura aluminum sliding door panel has a patented Adjustable Step-Over feature which allows you to adjust the height of the flap to the most comfortable fit for your pet.
  • The top of the flap should be positioned to be at least 1” above the top of the pet's shoulder.
  • If the factory setting is not suitable, please adjust it before proceeding. Otherwise, proceed to the Installation Instructions section.

Step 2 Rearrange the Pieces (Optional)

  • Simply slide the pieces up and out from the bottom half of your panel to rearrange.
  • Loosen a bottom screw if the pieces are too snug to move.

Step 3 Reconnect the Pieces (Optional)

  • Replace the spacers and the Pet Door Assembly by sliding them back in a different order to achieve the desired height.
  • You can move the spacer below or above the flap to raise or lower the flap height.

Step 4 Screw the Pieces Together

  • It is critical that the bottom piece is placed at the base. This is the designated attachment point for the screws. You can now assemble the patio panel.

Step 5 Align the Connectors

  • Remove the 2 flat head sectional connector screws from the exposed part of the connector on each side.
  • Align the aluminum connectors extending from the bottom flap panel section with the top glass panel section.
  • Press the aluminum connectors into the holes at the bottom of the top glass panel section.
  • Ensure locking cover & height adjustment locks are on the same side.

Step 6 Tap the Pieces Together

  • Gently tap the bottom surface of the panel against the ground to completely insert the connectors.
  • Protect hard surfaces to prevent scratching.
  • The components of the panel are designed to slide together very tightly.

Step 7 Secure the Sections

  • Fasten the two panels together using the four flathead screws.
  • Use the included flathead screwdriver to tighten all four flathead screws so the two halves of the door are pulled together.

Step 8 Adjust Spring Mechanism

  • Loosen the height adjustment locks at the top of the pet panel. This allows the spring mechanism to move freely up and down.

Step 9 Test Fit the Panel in Your Track

  • You want to put the pet door in your track before applying any weather stripping to ensure it fits. If the panel fits well, proceed to the next step. See the Troubleshooting Section if you encounter difficulties.
  • To insert the panel into the top track, push up against the spring mechanism and swing the bottom of the panel up and over the threshold.
  • Seat the panel on top of the small guide rail in the track.
  • If you can't quite get it in the track, try swinging in from the outside as the outside track wall may be shorter.

Step 10 Apply the Weatherstripping

  • Once you're sure the panel fits, remove it from the frame and lay it on its side on the ground.
  • For foam weatherstripping: Peel the backing off the foam weatherstripping. Press it along both edges of the panel, trimming as needed with scissors to ensure a snug fit.
  • For rubber weatherstripping: Clean the edge of your sliding door or window with rubbing alcohol to help the weatherstripping stick properly. Starting at the top or bottom, peel and press the strip into place with the folded edge facing indoors—align angled cuts if you have two pieces. For best results, apply the seal to the sliding door or window, but it can go on the pet door panel if needed.
  • Foam weatherstripping is applied onto both sides of the panel, but the rubber weather stripping only applies on the side of the slider door. Your panel will come with one type of weather stripping. You do not need both types.

Step 11 Install the Draft Stopper

  • The center post weather seal strip (draft stopper) should be installed on the inside of the home.
  • It can install on either the back edge of the sliding door panel or the leading edge of the stationary panel.
  • This strip prevents air from leaking between the sliding glass door and the stationary panel.
  • Trim with scissors as needed. Clean the edge of your patio door with rubbing alcohol before installing to assure a good seal.

Lock Details

a lock can secure your slider in place

Since you cannot lock your sliding door to your panel pet door, we have provided you with alternative locking methods to secure your home:

Installing the sliding door clamp: This clamp has a screw that tightens by hand to prevent the sliding door from moving beyond the clamp's placement. For doors manufactured with the glass slider on the inside track, the lock can usually be installed on the door's raised track.

If you aren't able to use the lock that comes with the panel: A great alternative to locking your sliding glass door is a Charley bar or dowel in the track. Both work off the same concept—they block the slider from opening. When engaged you cannot pull the sliding door away from the pet door panel.


use a charley bar or dowel in the slider track to secure your door

Variable Magnetic Resistance

Other Installation Options

Semi-Permanent Installation:

You might choose to secure the panel in your track with screws. This can be done by drilling screws at an angle in the top and bottom tracks. We recommend doing this from the outside to minimize damage to the sliding glass door frame. One-way screws will prevent tampering or removal of the panel from the outside.

you can screw your panel into your slider for a more permanent installation

Some stationary sliding door panels can be unfastened and moved over to one side so that you can install the pet door panel between the jamb and stationary panel.

Avoid damaging your sliding glass door by checking that your door can move and that you can reinstall it properly before trying to uninstall the unit.

You will still lose space in your slider to move through, however, you will be able to use your existing sliding door lock to secure your home. Installing your pet door this way is also great in that you already have an alarm system in place.

If your sliding glass door slides on the outside track, using an alternative lock might not be possible, so this allows you to still lock your door.

NOTE: You can do the stationary panel install with the regular spring actuator method--no need to screw it in.

What if my panel is slightly too tall?

The spring-loaded adjustment piece at the top can be trimmed by up to 3/4". Remove the piece using a Phillips-head screwdriver, and shorten the flanges with a hacksaw or suitable tool. To maintain proper panel installation, do not exceed a 3/4" trim.

What if my panel is slightly too short?

Height extension pieces are available, adding 3/4" to the top of the panel that slides into the upper channel. These extensions are made from matching aluminum for consistent color.

For those DIY enthusiasts requiring extensions beyond 3/4", you have the flexibility to create your own using readily available 1-inch nominal wood, which measures 3/4" thick. A 1x3 piece provides a practical and cost-effective solution.

For a clean fit, cut your DIY extension to match the panel's width, then slide it into the top channel. A matching paint job will blend it seamlessly with your frame. To ensure stability, especially with larger extensions, secure it with screws.

What if hardware for the locking latch is preventing the door from sealing properly?

You may be able to remove the hardware, as it is sometimes secured with just a few screws.

If removal isn't possible, try installing the panel on the stationary side, as described here.

If neither option works, you can shim the panel to align it with the lock face. Depending on how far it protrudes, consider using thicker foam weatherstripping or a small wood spacer between the panel and the wall jamb.

My slider isn't closing evenly against the panel?

If your slider isn't level—a common issue in older homes—you may be able to adjust the wheels to realign it. Most doors have an adjustment screw near the bottom that allows you to raise or lower the wheels slightly.

If the slider is level but still misaligned, the issue could be with the metal height adjustment lock at the top of the panel. In some cases, you can use a rubber mallet to straighten out any slight curves.

If the height adjustment lock is hitting the edge, it may indicate that the bottom of the panel is seating deeper into the jamb than the top, creating a widening gap as you move downward. To correct this, use wood shims or weatherstripping in the jamb to push the bottom of the panel outward.

What if the panel is wobbling slightly back and forth?

If your track is wider than 1" you can use small wooden shims or extra weatherstripping to fill in the gap inside the top and bottom tracks. By placing the material inside the tracks you won't be able to see it, but it will stabilize the panel. You might also try semi-permanently installing the pet door.

The slider is on the outside track? How do I lock it?

If you're trying to lock the door, this can be an issue since a clamp lock, Charley bar, or dowel in the track may not work effectively. In this case, a foot lock is a good alternative, though it requires drilling into the front end of the stationary panel frame and a small hole in the sliding door frame.

Depending on your slider's handle design, you might be able to position a Charley bar between the handle and the edge of the stationary panel. This would allow the slider to press against the pet door, preventing it from being opened.

Alternatively, consider installing the pet door between the stationary glass and the wall for added security.

My pet is having difficulty with the large step-down going out or coming in.

In this case, you can use a ramp or small steps to reduce the height of the drop. Ensure that the distance between the top of the flap and the ground is enough for your pet to pass through comfortably without ducking or brushing against their back.

What if I have an alarm system?

The alarm company might be able to come out and move the sensor for you. So instead of one part being on the door and the other on the jamb, you would end up having one side on the panel that matched up with the one on the sliding door.

As there are many different types of alarm configurations we would recommend that you always consult the alarm security company first to discuss your options.

Videos

The Thermo Panel 3e Patio Panel Pet Door


Endura Thermo Panel 3e


Installing a Patio Pacific Panel Pet Door


How to Measure Your Door for a Sliding Glass Pet Door


The Leaf Blower Test


Endura Flap Dog Doors Durability

FAQ

Warranty

Endura Flap products have a lifetime warranty against defects in materials and workmanship under standard regular use. Endura Flap® Pet Doors Are 100% Designed, Engineered, and Manufactured in the USA. They are handmade for quality work in San Luis Obispo, California. 

We will replace any defective parts at no cost to you. Defective parts may include incorrectly sized flaps, bent or dented frames, or improperly fitted parts.

Customers living outside of the continental United States are responsible for shipping costs as well as duties and taxes (if applicable) for any replacement parts or services covered under the warranty policy regardless of the replacement part or service's original cost.  

Important Note:

  • Endura Flap® pet doors have a lifetime warranty for normal wear & tear and manufacturing defects (dog-chewing is not covered).
  • Damage caused by not using the product as intended, improper installation, and chewing is not covered under this warranty.
  • Endura Flap Pet Doors used in a commercial application like a Kennel or Boarding facility have a three year warranty.

Customer Reviews

Customer Reviews
4.5 Based on 322 Reviews
5 ★
71% 
230
4 ★
18% 
58
3 ★
5% 
15
2 ★
4% 
12
1 ★
2% 
7
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Filter Reviews:
RH
05/02/2025
Ronen H.
United States

Great product!

Easy installation and looks sturdy! I used (struggled with) another brand for 3 years. Looking forward to years of use and great customer service. Thanks, guys!

NR
04/06/2025
Nancy R.
United States

Just ok

its a well made door. My only issue is i have a three door slider and none of the locks offered work on it. Also my small dog and cats are afraid of the flap.

AB
03/05/2025
Auntie B.
United States

Happy dog, happy humans

I ordered and rx'd a black medium door for our 7.5lb chi. T'was an easy install for the in-house tech. We opted for the medium size to accomodate other visiting 4 legged friends. Our little chi has no problem with the extra weight and size. A short session of treats and praise on both sides of the flap encouraged her to accept and use it immediately. We all depend on her to do the right thing and have not experienced any in-house errors since installation. At night, we use the slide-in barricade to keep her inside and other night time critters out. I applied bold decals to the barricade so the chi would more easily avoid bashing into it. We are pleased with the product so far.

CM
12/10/2024
Cheryl M.
United States

Endura flap

I did not receive instructions with my order. Fortunately there were instructions on the website. I was hoping that the flap area would be better sealed allowing less cold air in.

D
11/24/2024
Danny
United States

Works great but hard to get a good seal

I love this pet door because it gives our dog (and us) freedom to come and go. It is sturdy and it looks like the flap could be used a few million times before it breaks, which is great. The door was also easy to install. The only downside is that it is hard to get the sealing foam to attach well, and every time we open and close the door, it becomes a little less secure. That said, after doing a lot of research, this one still seems to be the best on the market so I would definitely buy it again.

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