Hi, I'm xkingdomheart, a low elo summoner. My english is bad so I'll say sorry right now LOL. Anyhow, Heimerdinger is the first champion that I bought. He gave me lots of wins since then, I never use him in ranked because I think that he is pushing to much and is an easy target for a gank. I played 6 dominion game with him, 5 wins and 1 lost. I was always in the top 3 in points (4 times 1st,1 time 2nd and 1 time 3rd). So I'll share you my build and tell me what you think about it. Thanxk it's appreciated.

PROS

Great pusher
Great defender
Awesome Damage late game
Easy to undersand
Can defend when he's not here
He is smart

CONS

Squishy
Weak early game
Doesn't have a good escaping tool
his stun is not constant
Mana issues when you stay on the field to long

GG SUMMONER SPELLS
This is probably the best summoner spell for AP. good at escaping, good at pursuing, good for dodging, good for initiat. There is nothing more to say about this spell.
This is one of the best spell for dominion. You run faster to the point you want to capture. You run faster to escape. You can run around your turrets.

ALTERNATIVE SUMMONER SPELLS
This is a good offensive spell. Deals true damage, can be useful in dominion but I wouldn't recommend this.
This is a better alternative than Ignite. It is more useful than ignite. Good when 1v1 but when, you getting gank at a point, you can only use this to one of them, witch makes this skill less useful.
This is a good pushing ability in dominion. Gives you gold when the super minion killed something.
What can I say about this spell, not awesome. Revive is the worst spell in LoL I think. However, it could be useful in dominion. strong speed for a certain time, and revives you lol. I don't recommend this.
Well heal is useful in the begining, when you are about to die, I do not recommend this item.
An good anti cc spell.
This is an awesome new spell, I tried this instead of ghost twice and worked very well, I recommend this if you don't like ghost.
WTF SUMMONNER SPELLS
Big time wtf spell, I never recommend this on heimerdinger. In dominion, you are constantly finding mana on the map, dying and returning to pool to have mana issues and you got lots of mana regen already.
Another WTF spell in dominion, nothing much to say about it.
Smite is just aweful in dominion, gives a bit more gold, but with the pace of gold you recieved in dominion, smite is not a major difference. ''you can push with it'', I would rather have flash/ghost/ignite/exhaust/cleanse/revive than to be able to kill 1 minion so we can push.

I got for the standard 9/0/21 of AP. having more mana regen and mana and mouvement speed is good for dominion.

Runes that I take
Magic pen in mark is the only great mark runes for AP.
Mana regen is great for champion that are spamming their spell. In dominion, you want to constantly spamming your skills to stop some one from taking a point, to kill some one, to defend something, to save some one & more. Missing mana during those times is not fun. For those that says that we don't run out of mana in dominion, we actually do run out of mana, with mana regen seals, I don't need clarity and I can spam my spell as often I want.
This allows you to spam your spell often. There is no blue buff in dominion soo you'll need a CDR.
Flat AP is for an good early damage, it is always good to have an early damage.

ALTERNATIVE RUNES
Makes heimer less squishy.
Gives a better damage late game, you lvl up fast in dominion soo this could be useful.
Gives heimer armor, makes him less squishy during begining of game, witch is very useful because he is missing 1 turret before lvl 5.

This is your bread and butter skill for defending points and pushing. I max this first. This skill is great with zhonya hourglass and is easy to use because it has auto-attacks, you dont have to choose the target. However the turrets become weak during end game. Even tho they become weak, they skill makes other summoner lose time in taking a point when the turrets are there cause they will always interupt them from taking the point, they need to kill that turret before and lose like 1/2 or 3 second.
&First of all, I would max the missile before if they don't have annoying carry AD. Reason why: this skills is faster, champion can't dodge this, and it's an multi target skill. For those that says: you'll prefer to have blind first if an AD like trynd, yi or gp shows up. I've faced an yi and gp before, I always maxed missiles tho. If a trynd shows up, I will probly have 2 turret near me, i'll missile him, him taking some damage, he will either attack me or turret, if he comes close enough I'll grenade him ( trying to stun ), he will be blind for a certain moment, 1 or 2 second ( because I'll probly not have maxed grenade ). he will try to kill me, I'll ult and zhonya hourglass. he will take lots of damage, he will probly ult, because of my 25% cooldown, when zhony will be down my grenade and missile will be up, I'll blind him again, and finish him with missiles. if not I have GA soo I'll revive and finish him with blind or missiles.
You wants to have this at lvl 6/11/16 for the cooldown. You want to activate your ult to save yourself, a point, a friend. For example, if they chase you and you put down your turret with ult that will slow them alot. Same thing to save a friend. Different stuff for saving a point. let's take an example that you and your team are far from a point that both of your turrets are, the enemy wants to take that point. They need to kill your turret first to get the point of the turret will constantly attacking them and cancel them from taking the point. when one of your 2 turret is about to die, activate your ult, and it will save about 2-3 seconde more time to deal with the turrets, giving enought time to reach them or taking other points.

FIRST ITEMS
++ 2
I start with a prostector ring because of it's hp, AP and mana regen. It's an awesome item that you can sell at end game. Yes you have mana issues if you stay a long moment on field. The boots is for early speed run to top point, you want to have top point the fastest possible. Like a noob, I ghost to the top point and take it. Most of the time you want to have 3 going top, 1 bot and 1 mid. However at 1 game, we lost the point because they had 4 running to top, we have a team fight , during that team fight, the one that was mid and bot got to one of their free mid point and took it. Those 2 red pot is for in case you got damaged when taking the point.

CORE ITEMS
+or
Zhonya hourglass is the ultimate skill for defending a point. They rush you, you do your skill, try to stun them, after the stun, when you about to die, you use the actives, your turret attacks them ( with the turret point ), zhonya is over, you could be able to finish them. About rabadon or Rylai, If you prefer having a stronger burst and having greater pushing power, take rabadon. If you prefer def and having more surviability, take Rylai crystal scepter. In the end take both of them. Change the order you want to buy them.

LATE GAME ITEMS
+
At the end of the game you want a GA to act like another zhonya hourglass, the times you'll revive, your turrets + the turret ( of the point ) will attack the enemies, while your cooldown will be refreshed. Abyssal scepter is not an obligation but I like having MR, AP and magic pen near my turret and enemies.

ALTERNATIVE ITEMS
An good spells against stealth, i would still sell it at end game ( buy this begining or mid-game ).
Good replacement for Abyssal Scepter. doesn't give MR tho =(.
Good item, gives CDR so you can reach 40%, act like another skill and gives AP. Take this against tanky champs.

With Heimerdinger, you want to defend with a certain combo. You combo should be:

2 x->-><->->->->.

After your zhonya hourglass, if theres turrets are missing, put some down. This should probly kill most champ in a 1v1 fight at your point. Except if they got smite or nunu. If the combo did not kill the champ. Your combo continues with :
->->.

That fills the fighting section.

For the plays section, You absolutly want to have the top point. When you have it, protect it with 2 turrets. Now, how to place the on a point. On the top point, place on up the turret's point and one down of it. Far enough so the AoE do not hit them bot, and placed at the middle so they can shoot both sides. For the middle point, go for left and right. For bot Point, go for down left and up right.

Strategies: You will often be on top point or near the enemy pool point. make sure you always grab those health pack to heal you. Another one of my defense strategies is to go to a bush near the point I'm defending, when they try to steal it, missile them and grenade them and run. Wait for CD and do it again. When they are low, finish them. One of my offensive strategies is to place turret where enemies could come from when I'll be taking the point. if they arrive they will either be surprised of my turret or continue their way. If they continue their way, I ult and continue to take to point.

Well that is probably all for my build, this is my first build soo I hope that you guys will like it, comment about it. It is appreciated thanxk. For the summary, Heimerdinger is a strong burst end game, good defender, strong at pushing, he is awesome in dominion & he is smart. Soo you need to play smart with him.