Appears to occur only in wide bore chanters. More open or varied fingering may help. Sides of reed may be leaking. Rushes may help. (Hegarty)

Staple eye is too open. Reed requires disassembly. (Sky)

Staple eye is too closed. Reed requires disassembly. (Hegarty)

Bridle may be too high: reposition it lower down nearer back. (Hegarty)

Refix or replace bridle. (Hegarty)

The reed may be leaking, check collar, also check corner. If the corners are leaking, trim them at an angle slightly. (Sky)

It's a bad piece of cane, start again. (Sky)

These steps are intended to be done sequentially.
1) Reed is hard to play: If the reed is hard to play, it may be too open; you need to close the lips a bit to see if that makes it easier to play and raises the 2nd octave. If a reed is adjusted to play easier then the 2nd octave will rise in pitch. If the reed has a sliding type bridle, then slide it a tiny bit back toward the staple end. If it has a permanent bridle, (you can also do this with the sliding bridle) take the needle nosed pliers and gently squeeze the bridle on the flat to close the reed a small amount.
2) Re-seat the reed: the reed is now a bit easier to play, but the 2nd octave is still slightly flat. Remove the reed from the chanter and wind a small amount of string around the bottom of the staple, so that when you put the reed back in the chanter it does not go in as far.
3) Adjust the bridle: Try readjusting the bridle toward the lips of the reed and squeezing the bridle on the flat side to close the lips. What you have achieved is to shorten the reed head.
4) Trim the lips: Shave a 1/64" sliver from across the lips of the reed. This will also sharpen the back D.
5) Re-bind the reed: remove the binding, loosen the head away from the staple, push the staple further into the head (1/16" or so) and tie the head back on with fresh binding. Now start from the top and try the different steps again.
6) Sanding the scrape: Sand the scrape a few strokes on both sides, readjust the staple and play it. Try and apply pressure so that more is removed from the "heel" of the scrape to produce more of a U shape rather than a V. As the reed gets weaker, the 2nd octave will rise. Shaving the corners can ruin the reed
7) Try another staple or unbind the reed, remove the head, insert a tight fitting mandrel into the bore and taking a small hammer, tap along the body of the staple to expand the inside diameter of the staple.
8) Try an extension of the staple: Get a small piece of tubing and fit an extension to the bottom of the staple so that you can seat the reed further out of the chanter. If the chanter is close to concert pitch 440-A then this can flatten the chanter so that it is not a the desirable pitch. (Sky)

Use a staple with a larger bore, or insert the staple deeper into the chanter head, or trim the lips to shorten the reed head. (Sky)

These steps are intended to be done sequentially.
1) Re-seat the reed: Generally the reed head is either too short or has a staple that has a bore that is too large, or both. First see if the reed will sit deeper into the chanter.
2) Tape or rush
3) Adjust the bridle: Readjust the bridle toward the binding or squeezing the bridle on the edge to open the lips. What you have now achieved is to lengthen the reed head.
4) Re-bind the reed: remove the binding, loosen the head away from the staple, pull the staple out of the head (1/16" or so) and tie the head back on with fresh binding.
5) Insert a wire: take a small piece of .010" x 1" guitar string, bend one end to form a loop to hold it in place, insert this into the bore of the staple. You can somewhat fine tune the staple by varying the length and/or diameter of the wire.
6) New staple: Try a new staple with a smaller inside diameter. (Sky)

Start with a new staple right away. (Sky)

These steps are intended to be done sequentially.
1) Scrape the scrape: This problem is usually caused by a reed that has been sanded too thin along the center line of the scrape. Shave the edges of the scrape on both sides to make the lips thicker in the middle. You may have to remove the head, lengthen the reed by pulling the staple out a bit, re-tying and clipping the lips to make them thicker.
2) Edges are leaking: Remove the head and take some find sandpaper and thin the edges so that they close properly.
3) Staunch the leaks: a small leak along the edge can be sealed with wax. I use the soft red wax that can be found on Gouda cheese at the supermarket. Make a small (1/2") ball of wax, hold the reed in your hand and rub the wax ball along the edges of the reed head two or three times until it seals. Do not glue the edges. This will ruin a reed. (Sky)

1)Control it: Develop a technique where you raise the chanter slightly off the knee whenever you play the 2nd octave E, thereby raising the pitch.
2) Tape it and play it: Place a small piece of tape over the small E hole covering around 1/3 of the hole more or less. This will flatten the first octave and to a less extent the 2nd octave also. Flattens 2nd octave, but less than the first octave. (Sky)

1) Play it: try increasing the pressure and see if it goes away. The E should take the same amount of pressure as the back D.
2) More tape.
3) Try a rush: take a short piece of wire/rush and cut it to length so the wire extends almost to the F# hole, and insert it in the bell of the chanter.
4) Alter the staple: remove the binding from the reed after wrapping thread around the head. Remove the staple and close the eye a few thousandths of an inch.
Some say that reeds that have a tone chamber avoid the problem with the E note. I have not verified this. (Sky)

Take a length of wire the size of a coat hanger or smaller and insert it into the chanter bore the entire length just past the back D hole. This will flatten the entire chanter. (Sky)