You're not using your words as effectively as you could be. Heuristics are mental shortcuts, bias is a systematic deviation from rationality. A heuristic can't be a bias, and a bias can't be a heuristic. Heuristics can lead to bias. The utility of a certain heuristic might be evaluated based on an evaluation of how much computation using the heuristic saves versus how much bias using the heuristic will incur. Using a bad heuristic might cause an individual to become biased, but the heuristic itself is not a bias.