there is a tank in the back with a float switch and if the water can't get in to the bottle it fills up and puts the full bottle light on even though the bottle is empty.you need to find the float tank and check the water can get in to the bottle and isn't blocked up with fluff somewhere.its a top off and side panel off job to get to the float switch/tank.Some models have a pump but these have the bottle at the top
ck
January 2011