Very poor customer service. We had a query about the actual running cost which we found quite high and above the figure quoted. Eventually we managed to contact an engineer who clarified the situation. The rep. who came to give us a quote did not tell us about the heater in the system. This was only mentioned after it was fitted. The actual brochure left after installation stated that the running cost of £40 referred to the heater being disconnected, Obviously you do need the heater to be connected up, otherwise cold air would be circulating throughout the house. Despite this misinformation, we would recommend the system. We have not experienced any condensation since installation