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

Thermo Panel llle
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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

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  • 5

    Posted by Debra on Oct 23rd 2016

    Love this doggie door. Fits well, magnetic flap prevents cool ai from escaping & warm air from entering. Nice weather stripping included. Door well made. Well worth the price.Easy for dogs to use. Took them less than a day to learn door. Sturdy & secure panel to close up flap when leaving home.

  • 4
    Excellent merchandise and company

    Posted by Chris Hopkins on Sep 17th 2016

    The experience was seamless even though we needed to return the first one we purchased due to a measuring error on my part. The door is very easy to install, looks great and with the bug warden it really makes a difference when we want to leave the slider open with the screen closed keeping the bugs out and the dogs don't have any issue getting in or out of the dog door. Great product and service.

  • 5

    Posted by Jeanette Mohlman on Aug 31st 2016

    Really like the door BUT we had to put in some screws to make it stable and strong enough to stop intruders. I would definately suggest purchasing the locking bar to secure the door, the lock included just isn't safe. Be aware that the ingress and egress space will be smaller. We got the small doggie door. the space we have to go in and out the open door is now 20 1/2 inches. It works for us just fine. All in all we love the door.

  • 5
    Great door

    Posted by Eric E Ehlers on Aug 4th 2016

    This is a great product and was just as easy to install as the video. I needed the extra tall for my slider. The owner of the company called me to let me know that it would be too tall an and I would need to trim about an inch of the top to make it fit. A hand held circular cutter and it was done in a matter of minutes. Now that's customer service! The locking cover is very secure and our puppy has had no trouble with the magnetic flap coming in or out. We used the enclosed training treats and our puppy had coming in and out down within a few hours. If you are living in a climate area that has harsh winters or harsh summers spend the extra money and get the "lo e" double pane glass. We highly recommend this product and Company

  • 5

    Posted by Cynthia Phuphanich on Jul 18th 2016

    This was absolutely without problem & PERFECT. Super easy installation, perfect fit. My Vizsla goes in & out easily. It fits neatly in same run as my screen door, so I can just shut & lock my big glass sliding door & lock at night or when away.