Marey heater produces water that is too hot even at low temperature settings.

Safety first: Risk of scalding. Lower the set temperature immediately and warn users.

Steps:

• Verify setpoint: Confirm the temperature setting on the Marey control panel is not accidentally set too high.
• Measure outlet temperature: Use a thermometer at a nearby faucet to compare actual temperature to the setpoint.
• Descale unit: Perform a descaling flush to remove scale that can cause delayed sensor response.
• Inspect outlet sensor: Check the outlet NTC sensor for secure mounting and replace if readings are clearly inaccurate.

When to call a technician: If water remains excessively hot despite a low setpoint and a new sensor, the gas valve or control board may be malfunctioning.