There’s a saying: “Better broken in body than corrupt in mind.” I rather like that saying. I know a sound mind is indeed more important than the functionality of your body! Lately, this concept reminds me of heating & air conditioning. I know, you are unquestionably unquestionably confused, however let me explain, just like a human can have a body that is at peak fitness level with no major health problems, yet if there is something seriously wrong with their brain, their body does them little good, so too is there a similar principle when it comes to Heating, Ventilation & A/C, then you can have a brand new, state of the art, energy efficient, perfectly sized heating & a/c, & it will merely be a collection of useless machine parts if the brain of the operation, so to speak, has a major issue that prevents it from toiling. I am of course speaking about the thermostat, but quite often, a homeowner will know that there was something majorly wrong with the Heating, Ventilation & A/C system itself, when in reality the thermostat, or the brain of the Heating, Ventilation & A/C system is to blame, but perhaps the batteries in the thermostat are dead. Maybe the thermostat is set inofficially & the homeowner is not aware of this; Whatever the case may be, the thermostat may unquestionably well be the most important component of a heating & a/c, because without it, the whole Heating, Ventilation & A/C system is useless. The thermostat is just about the first thing I would check when I detect a problem with my Heating, Ventilation & A/C system.