The persons concerned can know this thanks to the invoice issued when the boiler is connected. If the document is no longer available, the nameplate on the boiler can help you. It is usually located inside the main cover. Depending on the model, the nameplate contains the serial number, manufacturer, model type and year of manufacture.
If you can no longer read the sign, the chimney sweep in your area can help you. It usually records regular inspections and can view its records for a fee.
If the local chimney sweep has already passed away or there has been a change of personnel, a heating engineer can also help you. Depending on the brand, type, model and wear, it can easily determine the age.
If the owners have lived in the house themselves since February 1, 2002 and operate heating systems that are more than 30 years old, they are exempt from the replacement obligation. However, the house loses value when it is sold because the new owner must replace the system within two years.