I have called because of the system malfunctioning, giving the sensor error. Got a vacuum cleaning of the furnace, and a filter (ok, a filter is needed for the air purifying system. $169 dollars - be aware, you have to replace them yearly and it has the technician visit attached. 169+129+tax). Servicing with Cozy Comfort is uncomfortably expensive. Btw, sensor error is still a mystery, I was told to call again ($130) when it happens. This is not the first time servicing the appliances with this company. It takes usually two visits ($129+tax each). First, the technician is trying to decide what is wrong with your devices and then orders parts, etc. Then comes again to fix. Here you have to pay for the part, visit and hourly rate. I am looking for a new service provider once the warranty is over.