I don’t feel it is our wifi thermostat

My Heating, Ventilation and A/C contractor is trying to blame all of the concerns with our gas furnace, on the thermostat, which I think is a lot of bunk. Maybe it is possible for the gas furnace to turn on and off intermittently if the thermostat is beginning to malfunction. I can’t understand how it will also provide an odor of something burning. If the thermostat were the problem, then I think the burning would come from the thermostat. My hubby was an industrial electrician and even he thought it was a lot of bunk and the Heating, Ventilation and A/C contractor had no idea what was wrong with the gas furnace. My hubby decided that he was going to go downstairs and look at the gas furnace on his own. He swore that he could repair the complication or at least tell the Heating, Ventilation and A/C supplier what was wrong and what was causing the odor. He went through the entire electrical idea in the basement and in the gas furnace. He found that there were some crossed wires. He called the Heating, Ventilation and A/C supplier and asked if they could send over the young Heating, Ventilation and A/C tech who had been to our beach house twice previously. My hubby took him to the gas furnace and showed him the burnt wiring. He asked him how much he knew about the wiring that went with this certain gas furnace and the young guy admitted that he didn’t guess certainly much about the electrical system. My hubby patiently showed him what to look for in the wiring so that he would never make this kind of a mistake with a gas furnace, in the future.
HVAC installation