Two family homes have been badly damaged after an outdoor heater caught fire and spread to the properties.

Emergency services were alerted to the house fire on Tripoli Road in Happy Valley, in Adelaide’s south, around 7.40pm.

Firefighters arrived at the scene to find one house well-alight and finding it had quickly spread to the house next door and two vehicles.

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One family had only purchased their home on Tripoli Rd just two months ago.

WATCH ABOVE: Homeowner’s son rescues pets from burning blaze

Homeowner Shiralee Lindner was at the supermarket when her son rang her, telling her their family home was on fire.

“It was a horrible feeling actually because I kept thinking everything was up in smoke,” she told 7NEWS.

Linder’s son was alerted to the fire thanks to a quick-thinking neighbour.

He fled, but not before he grabbed his pets.

An outdoor heater, a chiminea is believed to have sparked the fire.

Firefighters at the scene told 7NEWS the blaze should serve as a warning to residents to clean outdoor heaters regularly.

The fire is estimated to have caused around $250,000 worth of damage.