All of the writing on this site is general information about air conditioning and heating systems in Dallas and Dallas-side homes, published so homeowners can understand their equipment and their options. It does not diagnose your system. No two houses or systems are alike, even on the same street and in the same quadrant of the metroplex, and one symptom can spring from a different cause in the next house over. The ranges printed here are planning figures for budgeting, never quotes. The contractor working your job confirms, before that work begins, what you will actually pay. Guidance offered here, about shutting a system down, checking a thermostat, or looking over a unit, extends only to what a homeowner can safely look at. Anything touching refrigerant, gas lines, or opened electrical panels is professional work, full stop. Nothing on any page of this site creates a warranty, a service agreement, or a contractor-client relationship.