Water heater cycles on and off frequently when there is a small hot water demand.

Safety: Frequent cycling can reduce component life but is not usually an immediate hazard.

• Increase flow: When drawing hot water, open the tap further to increase flow and reduce cycling.
• Avoid very low flows: Do not try to run the heater at a trickle; this is below its stable operating range.
• Check for recirculation: Ensure there is no cross-connection between hot and cold pipes or incorrectly installed secondary return.
• Professional adjustment: An engineer can verify modulation and sensor operation and suggest system changes if needed.