Ever tried running Syndra into the match up? She's one of Heimer's hardest counters simply because you can push away, outrange or throw his turets at him. Other Mid lane matchups that are good against him are Varus, since his aa's and q largely outrange his turrets and you can pretty much free farm them with auto's. Also, Vladimir can pretty much use his turrets as a free healing source.
For toplane stuff like Sion or tryndamere do well against him. Sion can shout his turrets at him, tank them in all ins and even if you do die you will very likely still trade 1 for 1 because of sion's passive and heimer's lack of mobility. Tryndamere can just press r and crit him 5 times in a row and tank his turrets and tower and run away like nothing ever happened.