CALDAIA ANODE 300x150x15

Function and technical context

Boiler anodes are cathodic protection elements designed to be electrochemically sacrificed in place of the metal surfaces of the vessel's heat exchanger or boiler. They work within the indirect cooling system, where seawater circulates inside the boiler, transferring heat to the closed fresh water circuit of the engine. Being made of zinc or aluminum alloy with high electrochemical reactivity, they attract galvanic corrosion and protect the metal walls of the exchanger, preventing perforations, leaks and the consequent entry of salt water into the primary circuit. Without adequate cathodic protection, the boiler can silently degrade leading to serious failures in the marine engine cooling system.

When to replace this part?

The most common symptom of an exhausted boiler anode is the appearance of pitting, localized corrosion or even small leaks in the exchanger, a sign that the anode has lost its sacrificial capacity and galvanic corrosion has begun to attack the base metal. It is recommended to inspect this anode at the beginning of each nautical season and replace it when it has lost approximately half of its mass, regardless of the time elapsed, since in waters with high electrical conductivity wear can be especially rapid. Replacing the boiler anode preventively is the most economical intervention to avoid a costly failure in the exchanger or a forced shutdown due to engine overheating.