September heating oil prices trended lower during the overnight and initial morning hours but turned higher heading into the US opening. Some traders indicated that early weakness came in the wake of private industry data that showed a much larger than expected build in US distillate stocks last week. Expectations for this morning's EIA report are for a build of around 250,000 barrels, which compares to the five-year average build for this week of the year of 800,000 barrels.