Root canal done 6 weeks ago but tooth is still sensitive to heat, is this normal?

No: It can be one of two things. The tooth may have an additional nerve in it that wasn't removed or there is another tooth giving you pain and the pain is difficult to localize. You need to go back to your dentist to evaluate your problem.

No: I would go back to your dentist and have him evaluate the tooth.

See your dentist: Not really. A tooth that has had root canal should not remain sensitive to heat or cold after several weeks. Another tooth could be involved or there could be a problem with the treated tooth. I suggest you see your dentist as soon as possible.

Root canal: The tooth that has had a endodontic procedure should have no thermal sensitivity. Root canals treatments should remove all tssues inside the tooth including the nerves that allow you to feel things. Some teeth have more than one root and multiple canals. If one of these little canals were not found and cleaned, you may still feel heat and other symptoms. A tooth next to the area may be source.