LG condenser dryer floods!?

LG condenser dryer TD-C700-40E. Empty water light / warning buzzer keeps coming on even though the water reservoir is empty. Water reservoir at top right of machine - don't know if it is filling, instead water is pooling in bottom of machine (not the drum, if you remove the condenser unit bottom left, stick hand in all the way, then feel about 2 inches of water!) Tip machine and it comes out everywhere. Lots of condensation inside the drum as well - and quite a high temp when open the door. Had the back / side off, no water tubes loose or signs of water around electronics. Machine is 3.5yrs old - used daily during winter (3 kids) but rarely during summer. Help please!!