It is not recommended to perform any maintenance on your Ariston gas heater yourself, even if it is simple, as you should always contact a professional maintenance technician to avoid any problems or damages that may occur due to inexperience or failure to adhere to the necessary safety procedures. Performing any incorrect maintenance on the gas heater can lead to a gas leak or fire, which represents a great risk to personal safety and property. Therefore, it is best to trust a specialized maintenance technician to diagnose the problem and fix it in a correct and safe manner.