THIS COMPANY PUT MY FAMILY'S LIFE IN DANGER. I would give negative stars if I could. This company did a "repair" on my furnace back in 2012 that was done incorrectly (under home warranty). Thankfully the fail safe worked over the years. Apparently the flame was turning on but the fan was not wired to turn on to blow heat so eventually the system would overheat and kill power as well as turn on the fan to cool the unit. I was feeling heat coming through the vents so I thought the system was working. This past summer I had NV Energy install a new thermostat. The installer never went into the attic (although Vern tried to implicate NV Energy as doing something wrong). When I switched to heat this winter, the unit would run for a few minutes then I would lose power to the thermostat. My initial thought was that there was an issue with the thermostat so I had NV Energy come back out to check it. They did. No issues with the tstat, told me to call a HVAC company. I was hesitant to call back to Windy City because of the many times they had to come out for the first "repair" (6+ times over a few weeks). I called another company, Air Zone Cooling and Heating, they took one look and told me the previous company "butchered" my system. In fact, they refused to work on my system because of the potential liability issue. They took pictures to show me what was done and talked me through what was happening and told me the danger I had been in. They turned off the gas and disconnected the electricity to not expose my family to more danger. They told me that the reason I didn't notice the issue prior to the new tstat was that the Windy City tstat is a battery operated unit so it always works as long as the battery is good. He explained to me that the NV Energy tstat works off the furnace low voltage and because the safety switch was tripping due to the system over heating and the tstat would lose power. So I called back to Windy City in the hopes that they would correct their mistake. Two visits later they told me they fixed the unit. I had them run through a cycle of the furnace with me and they did. I paid them almost $530 because they said the timing board was bad. Not trusting them I called the Air Zone back to make sure things were safe and Windy City was no longer putting my family in danger. He ran some diagnostics and determined that the repair was now done correctly and that the new wiring is what should have been done years ago. I showed him the invoice that I paid to Windy City and he was flabbergasted. He let me know that Windy City RIPPED ME OFF. He told me on his first visit, the first thing he checked was the timing board (because the fan wasn't turning on). He put in a brand new timing board and the fan never came on like it should. So replacing the timing card DID NOT REPAIR MY UNIT, IT WAS THE WIRING CHANGE that made the fan turn on. Windy City charged me for replacing a timing board that was not bad to cover up their mistake from years ago. And in the mean time charged me for replacing a board that was not bad. I called and emailed with Vern at Windy City in an effort to correct the situation. They refused to admit that they made any wiring changes, I even sent before and after pictures showing the change in wiring and the written reports from Air Zone. They were unwilling to budge and kept insisting that the timing board was bad. Vern offered a one year membership into their Premier Club for free in which they'll come check my unit twice a year. What a joke!!! There's no way I'll have this company near my house ever again. I will be working with my credit card company and small claims court, if necessary, to get my money back. If I can save someone the hassle, please stay away from this company.