Error 14 appears and the Richmond tankless heater shuts down; unit may feel very hot to the touch.

Safety first: Turn OFF power and gas. Allow the heater to cool completely before touching internal components.

• Check water flow: Ensure all isolation valves on the hot and cold lines to the heater are fully open. Verify that faucet aerators and showerheads are not clogged.
• Clean inlet filter: Remove and clean the cold water inlet screen to restore full flow.
• Descale heat exchanger: Use the built-in service valves to connect a pump and hoses. Circulate a manufacturer-approved descaling solution through the heat exchanger for the recommended time, then flush thoroughly with clean water.
• Inspect overheat sensor: Locate the overheat sensor on the heat exchanger. Check wiring and replace the sensor if it appears damaged or tests out of specification.
• Test operation: Restore power and gas, reset the unit, and run hot water. If error 14 recurs, a technician should evaluate for internal restrictions or control board issues.