1. First, let’s check to see which setting the Smart-Mix Dial is on. If it’s too high, (heavy traffic typically) a lower setting may be needed if too much solution is being released.
2. Next, remove the SmartMix bottle from the unit. Check to see if the cap is leaking solution when off of the unit.
3. Check for proper placement of the o-ring on the SmartMix Cap Insert (some o-rings are detachable and need to fit over the straw; others are molded to the cap).
4. Check for the black or red tank gasket on the SmartMix Bottle Cap. If the gasket is lodged in the base, reattach it by pushing it back over the lip. If it’s lost, you can get one here: http://www.bissell.com/parts/?sc=part&productid=22496&partid=4605
5. Check for the black or red tank gasket on the on the bottom of the Tank-in Tank® Assembly. If the gasket is lodged in the base of unit, reattach it or order a replacement (it’s the same as the SmartMix bottle, see above).
6. Check the valve on the bottom of the Tank-in-Tank to make sure water will come through when the x-valve is pressed. The bladder may be empty or the valve may be blocked internally. If no water comes out when you press the valve, you’ll need to order a new valve. You can do so here: http://www.bissell.com/parts/?sc=part&productid=22496&partid=4432
7. How hot was the water that was put into the tanks for cleaning? Only hot tap water should be used, no boiling water, as it can damage the tank. If it’s damaged, you can replace it here: http://www.bissell.com/parts/?sc=part&productid=22496&partid=4517
8. Check if the small rounded tabs on the floor nozzle are locked in the slots on the top of the base and not inadvertently lifting the tank up out of place.
If you’re only getting solution, at this point it might be best to take your carpet cleaner to a technician. You can find your nearest BISSELL® Authorized Service Center by clicking http://www.bissell.com/service-centers/ or by calling 1-800-263-2535 and choosing option #1, available 24 hours a day.