I noticed in the morning that we were not getting hot water. I checked the water heater and the thermostat indicated an error code (LED's were lit in a certain sequence). I called DE and was connected to the customer service department in under 2 minutes. The customer service rep I spoke to was quite courteous and helpful. She gave me a few options for a service window. The technician arrived at the early side of the service window, which I was pleased with. He diagnosed the issue very quickly and replaced a defective part on the water heater. We had hot water again in less than an hour. (The parts and labour were covered under our rental contract for the water heater.)
If every company delivered service like this, the world would be a happier place (and we probably wouldn't need websites like this).