I have been a customer for over 15 years. I bought 2 new furnaces- one for a home I sold 3 years ago & one for present home. Never a problem.I signed up for annual maintenance. The maintenance is great. Today, I thought I had an issue with the furnace; my house was cold. I called and within 24 hours there was a technician at my house. Turns out I had a bad thermostat which I had suspected.He had 2 models on him, and he installed one. He also mentioned the WiFi feature, and offered to put it on my phone. (My luck with my new iPhone is abysmal.)Normally I would have resisted putting another app on my phone, but so glad I had the tech do it.1. He had a couple issues getting the thermostat and phone to connect, but he knows the app & what to do.2. The app is way easier to use than the thermostats. Love it!MM Comfort aka Home Care Alliance is AWESOME!