4 Steps to Clean a Heat Exchanger With a Garden Hose
- Turn off gas and power, then remove access panels to reach the heat exchanger.
- Flush from the bottom up with a garden hose at steady flow, no nozzle, to push debris out the top.
- Gently brush scale or soot with a soft nylon brush; hard bristles or a pressure washer will damage fins or tubes.
- Avoid chemicals unless you know what you are doing; a simple water flush twice a year is enough.