The other day I wen to clean my teeth with my Waterpik. I turned the Watepik on and something was wrong. Water was spraying on the wall. I thought I had the tip pointing in the wrong direction, but no. The hose was broken just below the handle. I didn’t want to have to buy a whole new unit just for a broken hose. I searched around the net and found I could get a new hose, but I thought I could use the hose I had. I just needed to figure out how to reattach it to the handle. I tried to figure out how to open the handle. I came close to hitting it with a hammer or prying it apart.
I continued searching, looking for into on how the replacement hose was supposed to attached, but I couldn’t find any instructions. I did find a replacement handle. I started thinking that I couldn’t reattach the hose to the handle I had. I ordered the replacement handle.
When the replacement handle came, I saw how it attached to the hose. I decided to see if I could use the old handle. I cut off the hose where the break was. There is a little plastic piece where the hose entered the handle. The piece locks the hose in place. Using a knife, I pried up the little piece to release the lock. The with the piece locked up, I pulled it out with some pliers.
Now with the lock removed, I needed to remove the small piece of hose. The hose is pushed onto a small plastic tube. I tried pulling the hose off, but that didn’t work. I ended up using a sharp pointed knife to slice the hose off the small tube. That worked.
I cleaned up the end of the hose. I slid the small plastic lock piece onto he hose. Then I pushed the hose onto the small plastic tube in the handle. Then I slid the lock piece down, and locked it into place.
My repaired Watepik works great. I still have the unused replacement handle. Not sure what I will do with it. I will probably just hang onto it in case the handle I have breaks.

This fix may or may not last. After having fixed the hose like this a couple times, I gave up. The hose just became too old and brittle. I had to replace the hose. This is probably a better long term solution. Here is a video I made on how to do that: