There are normal signs of wear plus tear on the Heating plus A/C unit. Sometimes the device will start to make a weird sound, however that sound is often the undoubtedly first alert that something is wrong with the Heating plus A/C unit. There are a number of problems that can cause the device to make unusual sounds plus several of the problems can be fixed easily. Some of those problems may require a licensed Heating plus A/C worker, but having a top rated professional check on the issue is typically the best idea, but my wifey plus I were having some trouble with the gas furnace plus all of us started hearing a weird sound. The weird plus weird noise persisted for 3 afternoons before all of us decided to call a professional, however neither a single of us recognized the noise coming from the heating machine, so all of us decided to call a licensed plus reputable corporation in the valley, every one of us ended up having an appointment on the same day plus all of us found out that the sound was coming from the gas furnace. Every one of us were lucky that the issue was not severe, plus the service did not cost a lot of money. The gas furnace service worker told my wifey plus I that all of us absolutely did the right thing when all of us called the service corporation. The guy suggested that it was typically a nice idea to call an expert when the device starts making a weird plus weird sound. That is the same advice for the gas furnace or the cooling system. The signs of wear plus tear can be weird stinks or sounds plus they are absolutely the way that the device alerts us when there is a problem.