The answer to 'heat exchanger short cycling' is that a short cycling heat exchanger is a common problem in HVAC systems that can be caused by a variety of issues. Short cycling occurs when the heat exchanger turns on and off rapidly, rather than running for a full cycle. This can lead to inefficient heating, increased wear and tear on the system, and higher energy bills.
Some of the most common causes of heat exchanger short cycling include a dirty or clogged air filter, a malfunctioning thermostat, a problem with the blower motor, or a issue with the heat exchanger itself. Symptoms may include frequent on/off cycling, uneven heating, and higher than normal energy usage.