Thermo Panel 3e with Endura Flap

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As low as $519.99

Product Overview

Thermo Panel 3e pet door with Endura Flaps has a very weather tight flap, and is spring loaded for easy installation

  • Easiest installation AND most weather tight flap on the market!
  • Tempered safety glass
  • Extremely weather tight panel
  • Endura Flap system - 1,000,000+ cycle flap
  • Full length magnets down both sides and bottom make flap very windproof
  • User adjustable rise (distance from floor to bottom of flap)
  • Locking cover included to keep pets in or out
  • Spring loaded top - easy no tools install
  • Heavy duty extruded 7/8" thick aluminum frame
  • Choose from several rises
  • Standard sizes: 74¾- 77¾, 77¼ - 80¼, 93¼ - 96¼ inch adjustment
  • ¾ inch height extensions available
  • Custom short sizes for sideways sliding windows
  • Endura Flap was the 2007 Dog Fancy Editor's Choice best pet product!
  • 10 year warranty on door, 15 year warranty on flap
The ThermoPanel 3e sliding glass doggy door uses the Endura Flap pet door which is super durable and very weather tight. In testing the flap survived beyond 3,000,000 cycles without a failure! Wind tunnel testing showed that the #8 size could withstand sustained 50 mph wind without blowing open. The key to its durability is that it swings on bushings at the top, instead of flexing to open like a typical soft vinyl flap. This pivot allows the door to swing without wear and tear. Endura flaps are available in taller sizes than most other pet doors. This means that it is easier to fit multiple dogs, as the flap can be lower to the ground and yet still be tall enough for a larger dog at the same time. This high "aspect ratio" has the side benefit that this new panel takes up less room in your sliding glass door.

In addition to the taller flap, this door also has a user adjustable rise. This means that the pet door height can be changed. This is the only pet door on the market to offer this feature. For a pet with short legs the flap can be installed as low as 3" off the ground. Small, Medium, and Large doors can be adjusted from 3" up to 5" if needed. For taller dogs the flap can be as high as 7" in the Extra Large flap size, and this adjustment can be made at any time, unlike other doors with rise options that are built to a particular spec and cannot be changed later. Video on rise adjustment procedure here.

The Thermo Panel 3e has a spring loaded top and is a no tools installation. A clamp on lock that grabs the track behind the sliding glass door provides security. The Thermo Panel IIIe is constructed with an extra rigid thick wall aluminum extrusion. Available in White, Bronze, and Satin (aluminum). Please be sure that the track is at least 1" wide to accept the heavy duty Thermo Panel framing.

These doors are available in three colors: satin is a brushed aluminum, similar to the bottom of a soda can, the white is bright white, and black.

Sometimes a door is a little bit taller than the top end of one of the adjustment ranges. If your door measures slightly taller than the top of one of the adjustment ranges, you may need a 3/4" height extension. This is a piece of the pet door framing cut to fit, and it just sets into the top of the pet door and does not need to be screwed in. These height extensions allow for a cheap and easy solution instead of having to order a custom, non-refundable pet door.

This 15 minute video details the installation procedure and answers common problems and questions:





Size Flap Dimension Rise Panel Width
Small 6 x 11 3 - 5inches 11 ¼
Medium 8 x 15 3 - 7 inches 13 ¼
Large 10 x 19 3 - 9 inches 15 ¼
Extra Large 12 x 23 3 - 11 inches 17 ¼

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Installation Instructions
Congratulations on your purchase of the finest panel pet door made, featuring the exclusive EnduraFlap.


Two piece doors start here.

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.

These installation instructions are for both the one piece panel pet doors and two piece panel pet doors. NOTE: If you are installing a two piece panel pet door, start at step one. For a one piece panel pet door, start at step four.

1 Piece Pet Door
1 - Panel Pet Door
1 - Foam Weather Strip
(for edges of the panel pet door)
1 - Center Post Weather Seal Strip
(vinyl strip)
1 - Sliding Door Clamp
PARTS LIST - 2 Piece Pet Door

Top half of panel

Gently tap the bottom surface of the panel against the ground to completely insert the connectors.
Note: These parts are specifically designed to slide together very tightly.

1 - Top Glass Panel Section
1 - Bottom Flap Section
1 - Foam Weather Strip
(for edges of pet door)
1 - Center Post Weather Seal Strip
(vinyl strip)
1 - Threshold Mount Dead Bolt
(with mounting screws)
4 - Hex Screws
(used to connect the panels)

(For the 2 piece panel pet door only)

1 - Hex Wrench
1 Piece

Panel Pet Doors
2 Piece


Fasten the two panels together using the four stainless steel hex head screws found in the panel packaging. Use the hex wrench to tighten screws so the two halves of the door are pulled together.

Note: Screw holes may look misaligned; this is intentional to ensure a tight fit. The panels will squeeze together as the screws are tightened.

Top half of panel


One piece doors start here.

This pet door incorporates a patented ‘Adjustable Rise’ feature which permits adjusting the height of the flap to the most comfortable fit for your pet. Generally, the top of the flap should be positioned to be at least as tall as the top of the pet’s shoulder (the ‘withers’). If the factory setting is not suitable, please adjust it as shown beginning in STEP 5 below.
Note: Figures A-C are shown for the #8 flap. Other sizes may have
a different number of rise options.

If you DO NOT want to change the pet door height (figure A) move to STEP 7.


To adjust the Panel Pet Door’s height, lay the entire panel on a flat surface (like the floor). Using a #2 Phillips head screwdriver, remove the bottom side-screws completely, and loosen the next upper side-screws one turn only (see arrows below).


Completely remove the bottom side-screws Loosen both sides one turn only


Once the bottom screws have been removed and the next upper side-screws loosened, the Pet Door Assembly and spacers can be removed by sliding the sections down (see arrows below). Replace the spacers and the Pet Door Assembly by sliding them back in to achieve the desired height (refer to STEP 4). Replace the bottom side-screws and tighten the next upper-side screws.

Note: Bottom rail has a U-groove. this must be positioned towards the top.


Loosen the thumb screws at the top of the pet panel. This allows the spring mechanism to move freely up and down. Note: Re-tighten the thumb screws after step 9.

Installing the threshold mount dead bolt lock: For doors manufactured with the glass slider on the inside track, the lock can usually be installed on the back of the slider using mounting screws provided. (Figure C)

IMPORTANT: Drill a 3/16” hole into the frame opposite the steel dead bolt lock. This hole MUST be 3/4” away from the inside edge of the door’s frame to avoid drilling into the glass. Drilling into the glass will cause it to shatter. (Detail 1) Note: For doors manufactured with the slider on the outside, the lock is installed on the leading edge of the stationary panel.


Cut the foam with scissors to the length of the pet door. Peel back the paper on the foam to expose the adhesive. Install the foam strip in the channels on both sides of the panel pet door.


Stationary Panel

To insert the panel pet door into the top track, push up against the spring mechanism and swing the bottom of the panel pet door up and over the threshold and into the rail at the
bottom. If you can’t quite get it in the track, try swinging in from the outside as the outside track wall may be shorter.

Installing the sliding door clamp: This clamp has a screw which 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. (Detail 2)


Mount the center post weather seal strip. (vinyl strip) This strip prevents air leaking between the sliding glass door and the stationary panel. The center post weather seal strip can install on either the back edge of the sliding door panel (Figure A) or the leading edge of the stationary panel. (Figure B) Note: Trim with scissors as needed. Clean edge of patio door with rubbing alcohol before installing to assure a good seal.


(14 reviews) Write a Review

14 Reviews Hide Reviews Show Reviews

  • 4
    Solid product with tiny flaws

    Posted by Richard Flack on Apr 7th 2021

    The product was easy to assemble and install. It's also very easy to take back out in a jiff. I'm in a high rise balcony that is very windy and it has no problem at all handling heavy wind gusts both structurally and the dog flap (though on occasion the dog door stays open when Candie comes back in and the wind is just right to keep it from closing).

    I ordered the bronze, but the vinyl weather strip that came with it is white, which against the bronze and dark grey-green of my balcony door/window trim, stands out like a sore thumb, and I've been unable to find anything similar at the hardware stores.

    The main flaw is that the top and bottom of the product is not "closed" on the sides, so one cannot attach weather stripping. This leaves significant gaps open for cold/wind to rush in. I have stuffed some foam to block and it's fine, but dead of winter will not be great.

    Overall, worth the custom made price. It only took about 2 hours to get my 15month shepherd mix trained to use it. She was scared to death at first, but with a lot of coaxing and rewards she started using on command and within a day was enjoying her newfound independence of coming and going onto the balcony.

    PDS response - that's a weird mistake to make. They have black draft stoppers, and should have sent a matching one. I will send you one, and apologize for the mistake.

  • 5
    Pet Door

    Posted by Rob and Alice Ferrell on Mar 26th 2021

    We love this door.

  • 4
    Thermo Panel sliding door insert with Endura flap

    Posted by Audrey J. Hackney on Jan 26th 2021

    This is a nice insert, heavy and sturdy. it is a lot wider than the one we had and we have to turn sideways to get through the door now. I had to take the magnets out of the bottom because the little dogs weren't strong enough to get through the flap. It does a pretty good job keeping the cold out but the strapping for the inside of the back door doesn't stay on at all.

    PDS note--We'll send another weather strip for you. Every once in a while we get one where the tape just isn't sticky. Clean the door surface well with something that doesn't leave a residue like rubbing alcohol before you apply!

  • 5
    Doggie door

    Posted by Lynn Stricker on Nov 20th 2019

    John was very helpful knowledgeable and answered the call ASAP and the windows gorgeous and the dogs love it.

  • 5
    Endura Flap patio door insert

    Posted by Arlene Noonan Noonan on Sep 7th 2019

    I am a repeat purchaser. I had one at my old home and needed a new one now. My dogs love it. They are much happier having freedom to go outdoors. Customer service guidance was wonderful. I highly recommend.

  • 5

    Posted by Karolina on Jun 26th 2019

    It’s a great door. The setup was really easy. I was very impressed with the weight of it, felt solid. Be careful during the assembly process the edges are sharp. Install went fast just pop it in that’s it. We got the XL size and set the rise to the max 9” as we have 2 tall Doberman. its perfect for our needs. It took them about a week to get used to it as one is stubborn, set in her old ways and one is a chicken but they both adjusted by the 7 day mark. It was a big deal because we were skeptical buying it thinking they just wouldn’t use it at all but we were very consistent with high praise and treats for using it every time in the beginning. Would not allow them to cheat and use the regular door to get out and they eventually let it go. Pretty sure the panels Provide better insulation than our existing sliding doors they are just very old. Overall we’re really happy with this door and feel it was worth the money!

  • 5
    Awesome Dog Door

    Posted by Trish Rogers on Oct 9th 2017

    I just wanted to thank you for such a great pet door. It had made our lives so great. We don't have to wake up in the middle of the night to let them out any longer. I'm also grateful for the customization on size since I have such an unusual size sliding door. No one would go as short as you did for us. Thanks again for such a great product.

  • 5
    Sliding glass door

    Posted by Bob on Jul 9th 2017

    This door is very easy to install and adjust. I live in the Midwest so I'm not sure how well it will seal for the winter. Time will tell. I added a charlie bar and it works for how we want it.

  • 5
    Pet owner

    Posted by Saundra Martin on May 20th 2017

    The door was custom sized to fit our 10' sliding doors - was easy installation and our puppy New how to use it from day 1 - she had been using the doggie door from our screened patio to the yard. Now she has 2 doggie doors - we llove the look of the door and the durability - very well made