Various signs can indicate the health of your boiler. These include unusual or loud noises, water leaks around the unit, inconsistent or no heating, and a sudden spike in energy bills. Another significant factor is the boiler’s age; if it’s nearing or has passed the 20-year mark, it may be more cost-effective in the long run to consider a replacement rather than frequent repairs. Seeking a professional’s opinion can give clarity on the best course of action.