Gas supplies will be gradually restored to all customers by mid-afternoon after repairs to the damaged Maui pipeline were given the all-clear.
Supply to the upper North Island was disrupted after a ruptured seam was discovered in the pipeline in rural Taranaki early Tuesday morning.
Teams worked around the clock to repair the pipeline, but a 24-hour wait was required before the welding work could be re-tested and the repairs certified.
Vector today said independent certification was granted overnight and purging and re-pressurisation of the isolated section of pipeline was completed this morning.
Retailers were advised at 4am that they could restore supply to all customers.