The answer to 'my heat exchanger won't turn on' is that there are several common causes, including a faulty thermostat, a problem with the ignition system, or a malfunctioning blower motor. Symptoms may include the furnace not starting at all, the blower not running, or the heat exchanger not getting hot.
Some potential solutions include checking the thermostat settings, inspecting the ignition system for issues, and verifying the blower motor is functioning properly. However, diagnosing and repairing a heat exchanger issue often requires the expertise of a professional HVAC technician, especially if the problem is with the heat exchanger itself. Attempting to repair the heat exchanger without proper training and equipment can be dangerous, as it involves working with high-temperature components and potential gas leaks.