The answer to 'why is my thermostat' is that there can be several common causes for a malfunctioning thermostat, including issues with the thermostat itself, problems with the HVAC system, or issues with the home's electrical wiring. Symptoms can include the HVAC system not turning on, the temperature not matching the thermostat setting, or the thermostat display not working properly. Potential solutions can range from simple DIY troubleshooting and adjustments to more complex repairs or replacement of the thermostat or other HVAC components.
If the thermostat is not responding at all, the issue may be with the batteries, a tripped circuit breaker, or loose wiring connections. These are relatively easy fixes that a homeowner can often handle themselves. However, if the thermostat is displaying incorrect temperatures, short-cycling the HVAC system, or not properly controlling the heating and cooling, the problem is likely more complex and will require a professional HVAC technician to diagnose and repair.