I have just fixed a silmilar problem on my #7920 model. The attachment spray and vacuum was working ok and the vacuum for the floor was working ok but no water was spraying to clean the floor. This implied a blockage somewhere in the water path unique to the floor cleaning. I eventually found a blockage in the heater exchange unit located in the lower part of the handle behind the large red light and speed pass indicator panel.
To get at the heater exchange you first need the remove both the cleaning fluid container and water reservoir to prevent spillage and unplug from the mains. Next remove the hose/mains lead caddy from the handle. Unravel the hose and mains lead and remove the lower two screws in the recessed holes from the back of the caddy. Then remove the two upper bolts from their nuts by unscrewing from the front of the upper handle. The caddy then just lifts off. The upper half of the handle will also lift off now.
Now remove the two deeply recessed screws from the rear of the lower part of the handle. With a little gentle persuasion the two parts of the lower handle can be parted (don't try to completely separate them). The heater exchange assembly can now be seen (a silver metal box with wires going to it and a couple of clear plastic tubes attached). Make a note of where wires and tubes run through the handle (take picture with your digital camera or phone if need be) for reference later. Pull off the x2 earth wires (green & yellow) and the black wire from the exchange unit (use pliers if they're a little stiff) and disconnect the inline connector going to the exchanger. All wires should now be disconnected (make a note or take a picture beforehand so you can remember where they came from). Next release the clips on the two plastic tubes on the exchange unit by squeezing them with a pair of pliers and moving them back along the tubes. The tubes can now be pulled off the heat exchanger unit. Be careful to keep them upright or any water in them will spill out.
Finally you can remove the heat exchange from the cleaner. Again make a note of how it locates in the handle (two lugs locate into recesses in both halves of the handle). You will notice a plate on the underside of the unit held on by x7 screws. Undo all the screws and the plate will lift off. You will now see a black matrix of channels and will probably see a lot of gunk within the channels and on the back of the plate you've just removed. Gently clean this off with a cloth. Try not to use any metal scraper as this will remove the surface coating. Now you have to clean out the two pipes at one end of the unit by gently pushing a thin screwdriver into the pipes whilst rotating at the same time. This is where the blockage is most likely to be so make sure these pipes are completely cleaned out. Be careful not to lose or damage any of the rubber grommets over the screw holes (n.b. there are no grommets on the outer two holes) or the sealing ring around the perimeter of the channel matrix. Once it's all cleaned out reassembly is just the reverse.
It may sound complicated but just take your time and make a note of everything or take pictures before disconnecting or removing anything and you will be successful.
Good luck! Don't forget if you get it repaired by a professional it will probably cost almost as much as the cleaner cost you in the first place!
Gary, May 2008
