You guys are wrong. I just got out of a game and it seemed to work up until the siege minion was killed. I was able to place all 4 turrets under the enemy turret without getting turret aggro. At some point something changed though causing the turret to aggro me. It may have been the laser from my turrets grabbing the tower aggro though. Here is a Heimerdinger guide that has a gif of the dive I'm talking about in it. There have been 10 patches since that guide was updated though.
- Turret will only target you if a champion is hurt by you or your heimer turrets (or alternatively there are no minions or your own turrets to take turret hits)
- You have to be in turret radius for it to target you (herp derp right?)
- The enemy has to be in the turret radius and then getting damaged for it to cause the turret to attack you,
- If the enemy champion is out of its own turret radius and you or your turrets damage that champion the turret will not attack you.
If for some reason heimer turrets do not cause tower aggro on YOU while an enemy champion and YOURSELF are in turret radius and your heimer turrets apply any sort of damage to the ENEMY CHAMPION then that is a bug. (and ill be the first person to admit that heimers kit is very bug prone, as is with Azir currently, the old days of the lane bully that used to be yorick and shaco boxes)