Water heater frequently cycles on and off rapidly while a tap is open.

Safety: Be cautious of temperature swings during testing.

Steps:

• Increase flow: Open the hot tap more fully to maintain a stable flow above the heater's minimum activation rate.
• Clean flow sensor: Remove and clean the turbine or paddle flow sensor to ensure smooth rotation.
• Check aerators: Remove faucet aerators that may cause pulsing flow.

Professional help: If cycling persists, a technician should check sensor readings and modulation behavior.