Remove the front panel by inserting a putty knife into the top groove of the panel in line with the lid opening on each side to release the clips. Tilt panel outwards and lift from cabinet. Check the air dome and air hose on lower left side of the tub for gunk. Pull the hose off the air dome bib and make sure its clean. If there is gunk in the air dome, use a turkey baster with hot soapy water to try and flush it out. The air dome is welded to the tub and is not removable. If there is no gunk buildup, check the hose for cracks/splits all the way up to the pressure switch behind the control panel. If all is ok, you need to check the pressure switch.