Upon arrival, the indoor unit had nothing lit up on the display, power was plugged in properly. Unplugged it, let it sit for a minute, plugged it back in. Waited for system time delays and warmup procedure. System heating normally at this time. Explained it is best to leave the temperature setting alone, don't turn the unit off at all during heating season, and if there's an issue to unplug it for a minute or two and plug it back in before calling us for a service call.