Fire marshals say a malfunctioning boiler caused a weekend fire that ripped through a row of businesses in Queens.

The Fire Department said Tuesday that the blaze, which started in the Acme Furniture Store on 37th Avenue near 84th Street in Jackson Heights at 9:53 a.m, had been declared accidental.

The four-alarm blaze forced the evacuation of dozens of residents from a nearby apartment building during the fire on Saturday, which took 3½ hours to control.

Miraculously, no civilians were hurt, but four firefighters were treated for minor injuries, authorities said.

In all, eight storefronts were destroyed, decimating half of the block.