Bosch water heater runs but then shuts off after a few minutes, requiring manual restart

Safety first: Turn OFF power and gas before internal inspection. Repeated lockouts indicate a safety problem.

• Check water flow: Ensure all inlet valves are fully open and the inlet filter is clean. Verify adequate flow at fixtures.
• Inspect venting: Look for partial blockages or restrictions in the vent and intake. Clear any debris.
• Clean sensors: Inspect and clean temperature sensors and ensure they are firmly attached to the pipes or heat exchanger.
• Thermal environment: Ensure the heater is not installed in a confined, overheated space without adequate ventilation.
• Professional diagnosis: If the problem persists, a technician should check sensor readings and control board operation.