Thanks very much for the reply. The heater does seem to be working as the clothes are getting warm, just not drying. I understand that the condenser unit works in the way you have described but the water will only condense if the unit is colder than the warm air being drawn through it, which seems to be the problem (ie the condenser unit is warm). In fact it does seem that the condenser is drawing in air so I am mystified why water is not condensing out.