The answer to 'my replacement keeps shutting off' is that there are several common causes, including a malfunctioning thermostat, a problem with the electrical system, or issues with the HVAC unit itself. This can lead to symptoms like the unit turning on and off repeatedly or not staying on for long periods.
Some potential solutions include checking the thermostat settings, inspecting the electrical connections, and ensuring the HVAC unit is properly sized for your home. However, if the problem persists, it's best to call in a professional HVAC technician to diagnose and repair the issue, as improper repairs can lead to further damage or safety concerns.