Along came a spider and a woman with insect spray - the washing machine blew up, the windows blew out and the woman was injured.

Police say the 66-year-old woman spotted a spider on the washing machine of her home in Kirribilli, on Sydney's north shore, about 1pm on Saturday.

She opted for insecticide and sprayed the spider which ran under the machine.

The woman pursued the spider, sprayed under the machine and it exploded.

The blast blew out the kitchen and bathroom windows and destroyed the washing machine.