It happened just before midnight on Thursday inside a two-story twin home on the unit block of Stacey Drive in Doylestown.
The fumes from the pressure washer overcame four people in one of the homes.
They are being treated at Doylestown Hospital.
Two others complained of being light-headed.
They were treated at the scene.
Everyone is expected to recover.
Firefighters have vented the property.
Get Action News on your website
