Hi
Hope someone can help, in the early hours of the morning lately we're hearing a rumble similar to the sound of air bubbles running through the water pipework and the intermittent sound of water pouring into the calorifier in the engine bay, similar to someone pouring water into a bucket with water already in. Now the calorifier in the engine bay doesn't have an expansion tank fitted, instead coming out of the top is a hose leading through an air vent grate in the side of the boat and out. Does this mean our system is never pressurised fully as it's open to the outside all the time? Could this be the cause of the noises we're hearing as it's driving us up the wall!! we're moored in a marina with electric hook up and have a second water tank under the bed with an immersion heater which gives us hot water at the moment, strange set up yes but it's what we inherited. Can I put some valves in the lines to and from the calorifier and actually isolate it when not cruising? We're living aboard now and using the hot water more before during weekends etc we never heard the noises.
Thanks in advance
Stuart