The refinery with a capacity of 94,000-barrel-a-day was closed due to a failure in the bleeder valve, a piping component.
During the shutdown, the company observed flaring from the refinery as all the bi-products and vapor out of the lines were burnt as part of safety protocols.
The refinery has not resumed production, but is scheduled to resume operations today.
Tesoro manager for government and public affairs Lance Tanaka said Tesoro has isolated the issue and has made repairs.
"We have already contacted the customers about alternate delivery schedules.As of now, there is no disruption to the supply," added Tanaka.
