Michaelnique

The bubbling anode is the central one, not next to the immersion heater, but facing another boat which I know has experienced some electrical issues in the past weeks. I've disconnected from shore power for now, that should stop stray currents flowing between boats if the culprit is the neighbour's boat, right? Will recheck any DC faults later.

Thanks Alan, Tony and MtB for the thoughts. To answer some of your questions, when I checked the wiring for the immersion heater, the neutral and ground wires sleeves were cut too short and those wires were a bit too close, so I'm thinking there was a fault here and the GI light has now switched off. Strange indeed that there is just one anode reacting, this is a marina in London so not especially brackish, but I'll turn the boat around to see if that changes anything. At some point, I was wondering if it might be bubbles trapped below the anode, coming up to the surface occasionally as this is not constant..

Hello, I have a narrowboat in a marina, connected to shorepower, and I've noticed that since recently an anode has been "fizzing" regularly, releasing small bubbles probably between the anode and the hull, making a typical sound. One of the lights on my galvanic isolator had also been on briefly, but off now as the fault was probably with the wiring of the calorifier. New anodes were added this summer and there were no problems before. Wondering if anyone has faced similar issues and has any advice? Could this be caused by nearby boats? Many thanks, Michael