holding tank for washer/dryer??

[BillyRay]

I also posted this in problems, but for those who didn't see it...does the washer/dryer drain to a holding tank...or straight to the city sewer connection?..mine seems to go straight to the city connection.if the city connection isn't hooked up it will overflow into the closet via the drain connection.

I was always led to believe that it went to a holding tank, but everytime I've used it , it's been hooked up to a city connection.