Katherine Heigl — Firefighters Rush to L.A. Home Over Steamy Affair

0329_firetrucks_wenn_exdA fire truck rushed to the home of Katherine Heigl moments ago — but our sources has learned … it was a steamy false alarm.

A rep for L.A. City Fire tells our sources, a call was placed at 1:36pm reporting a possible fire — and firefighters scrambled to the scene.

But Katherine”s rep tells our sources, the alarm was triggered by some steam inside the house — the source is unclear. No one was hurt.

It”s also unclear if Katherine was home at the time — but her husband Josh Kelley (above) greeted firefighters at the gate … before sending them on their way.