Your tankless water heater’s heat exchanger may become corrupted by mineral deposits, increasing energy costs and shortening the unit’s lifespan. You can perform this maintenance yourself if you feel comfortable doing so, but it is recommended that you consult the manufacturer’s manual for detailed instructions and safety precautions.
Inspect the Flue
The flue system must be inspected regularly if you have a gas tankless water heater. It can get clogged with outside debris or gas byproducts that cause soot and carbon monoxide to be blown into your home. It can also cause a malfunction of the unit.
If the unit is outside, it should be inspected to ensure that there are 30 inches of clear space around it and that no plants or storage are blocking airflow. Some units require a filter on the air intake, which may need to be removed, cleaned, rinsed, dried, and reinserted.
A professional plumber …