Water temperature too low at taps, but the burner cycles normally.

Safety: Be aware of scalding when increasing temperature setpoints.

• 1. Check setpoint: Increase the DHW temperature setpoint on the ACV controller to the recommended level (often 55–60°C for storage tanks).
• 2. Verify burner output: Ensure the burner reaches full modulation when there is a large demand. If it remains at low power, there may be a control or gas issue.
• 3. Inspect mixing valve: If a thermostatic mixing valve is installed on the outlet, adjust it according to the manufacturer's instructions. Replace it if it does not respond to adjustment.
• 4. Descale heat exchanger: In hard water areas, arrange for descaling of the ACV heat exchanger or plate exchanger to restore performance.

If demand regularly exceeds the heater's capacity, consider upgrading to a larger ACV unit or adding storage.