ok so, some of you reading this may think im crazy for not building rockets, but trust me, heim rly needs the stun. Also the damage output from the grenades combined with the ap from the deathcap is amazing. I have played this build countless times and, no matter how good the other team was, i have pwned. Wat i mean is, if u know how to place the grenade, u will KILL ALL!
Like always, u want to build the turrets to the highest lvl ASAP.
Ok so now to talk about the masteries and spells. So i did the same thing as the champion spotlight, u need the mana regen (heim is a BIG mana drain) From there i built cooldown reduction and what ever else that the tree forced me to get.
Ok; as i said earlier, heim is a BIG mana drain. So, he needs to have clarity. Also, since u will be the main target in team fights, u need either ghost or flash. I like to use ghost because it can be used for traveling across the map.
Now for the main topic, my build.
Heim has a high ammount of health (as seen in the stats chart in-game) and he has his turrets, so, instead of boots or health, i go straight for ability power. This will give u a huge advantage over ur opponets as the enemy will try for speed or health items.
Now the next part of my build is very maileable. wat i mean is, you can buy the items in any order. Frozen Heart is normally the one i build first because the cooldown reduction is great for scary situations. Then i build Rod of Ages cuz eventually u will need the survivalbility. (lol i cant spell) Normally i build the shoes earlier than this, but i wasnt very strategic in my ordering here. With the shoes, u might want to build them second if ur going up against a tank and the movement speed is always nice (but that is why we have ghost)
Lastly, in order to pwn late game, u need more AP. So we get another deathcap (starting the build with the Needlessly Large Rod of course)
For the end item, ur going to need to sell ur pendent, but its worth it. This last item depends on the game. If ur doing well and not dying much, u should build another deathcap (3 Deathcaps= pwnage) Or, if ur being targeted alot and dying rly fast in team fights, ur gonna wanna go with the hourglass, for obvious reasons. The game normally ends before u get to the last item, so it doesnt rly matter anyways.

Now for gameplay
With heimer, ur gonna want to solo. Ive found that he can be the best solo'er in the game if u play him right. Remember to keep ur grenade rdy for mias and harrassing, a little stun can go a long way ;) Heim also needs the golem buff (with it he is INVINCEABLE)
When going for golem, make sure u have both turrets rdy, especially before lvl 9.
Place down a turret before attacking, so u dont draw agro. Then stun the golem so he cant hurt the said turret. Take out the two other monsters while placing another turret to maximize damage output on the golem, then just spam grenades and rockets until he dies.

Harrassment is a big part of laneing with heimerdinger. Harassment can push the enemy back to their base and clear the turret for easy distruction. This is where the grenades come in. The grenades are superior to the rockets due their ability to be placed where u want them. Rockets can only attack the enemies closest to them. When harassing the enemy champ, try to aim behind the champ. Because the HUD is clearly visible, the enemy will try to run to get away from the damage. So, if u aim behind the champ, u should be able to hit them.

Anther good technique for harassment is harassing with ur turrets. Due to the new patch, ur turrets now attack enemy champions if they deal damage to u or a teammate. So i created a great combo for this ability.
U stay in the middle of the minion line and place turrets next to u (if ur faceing a ranged champ, u should position urself further back in the line)
U then allow the champ to hit u. This is what ques the turrets to attack the enemy champ.
Before the enemy runs away from the damage, u stun them in place using ur grenade.
U might not want to do this if u are facing a tank late-game due to the magic resist that they might get. U also might want to stay away from anyone with a good damage output (like veagar or ryze) But this combo can be used for most champions effectively.

Though u will be able to take down most champs in seconds, dont get too cocky. If u are ganked, just stun and run. Ur turrets should do enough dmg to push them back, so just worry about staying alive. Also, Try to stay back in team fights, ur no good if u get focused down and die.

With this build, u can one-hit minions with ur grenade. So if u see a lane thats not being pushed by either side, feel free to run down there and spam ur spells for farming!

just a fun side note; i have solo'd the baron nasher with this build :D

The items and skills are great, but the real deciding factor on how ur gonna do with heimer is ur skill lvl. I practice in custom games every day before i play for real. Practicing can be a great way of getting used to any charecter actually. It helps u get used to their skill shots, spells, combos, and even dance moves :D No matter if u play heimerdinger as ur main or just some charecter to have fun with, HAVE FUN!

-VERTOK