The answer to 'how to clean heat exchanger' is to regularly inspect and clean the heat exchanger to ensure it is operating efficiently and safely. The heat exchanger is a critical component of your HVAC system that transfers heat from the combustion process to the air that circulates through your home.
To clean the heat exchanger, first turn off power to the furnace and allow it to cool completely. Then use a soft brush or vacuum with a brush attachment to gently remove any dust, soot, or debris buildup on the heat exchanger coils. Avoid using harsh chemicals or abrasive tools that could damage the delicate components. If you notice any cracks, holes, or other significant damage, it's best to call a professional HVAC technician to inspect and repair the heat exchanger.