"It was a huge explosion and the lines, which were live, were hanging all over the road. It was pretty scary," Mrs Seal said.
She ran out to see if the driver was all right but paramedics and police were already at the scene.
Their house was without power all day, and their microwave will have to be replaced as it was blown out during the power surge.
Gary and Robyn Mitchell of Tawhero also woke to a loud bang around 6am.
"I immediately thought something had fallen down in the garage, so I got up, and saw there was no power," Mr Mitchell said.
He could smell burning, but could find no damage or identify the source of the burning, so he went back to bed.
It wasn't until Mr Mitchell got up later in the morning that he discovered his television, electric garage door, and microwave had blown, and the phone had been "blown off its socket".
"That wasn't a good start to the day," Mr Mitchell said.
The meter in the Mitchells' powerbox had also gone and, although Mr Mitchell was able to fix it, he was advised by Powerco staff to keep the power off until an electrician could safelyreinstall it.
"They told us that if we just switched the power back on it could start a fire, and the insurance company wouldn't cover us," Mr Mitchell said.
Powerco's acting network operations manager Dean Stevenson said power was cut to about 1400 properties in Springvale, Castlecliff, Mosston, and Tawhero. Most of those had power restored within an hour, but about 200 were still without power yesterday morning.
Mr Stevenson said the damage to electrical appliances was caused by a power surge which happened when the 33kV lines clashed with the 11kV lines.
He said Powerco had arranged for an electrical inspector to check each affected property to ensure the power supply was safely reconnected.
Customers should contact their insurance company if their appliances or electrical equipment have been damaged.