What type of topper (burner) are you using. 3 flashes is usually a short, but you may be trying to use something with too low resistance. Also make sure the
threads are clean.
It is also possible that you are not making a connection (although this is more unlikely with flashing). Ego
batteries are notorious for having the center (positive) pin on the battery getting pushed in. Without turning it on (don't press the button) try to gently wiggle that center pin out just a hair. Use a tiny screwdriver, straight pin, or similar.