We have an immersion heater in our home, with a water tank in the loft and a hot water tank in the airing cupboard. We keep the water on at all times to ensure a steady flow of hot water in our house.
Recently the tank has woken me and my partner up at nighttime by making knocking and bubbling noises. We have got up to investigate but can't see anything untoward.
Could there be a problem or is this normal? It seems to be at all times, whether we have bathed/showered or just filled the kettle. We don't have central heating and so perhaps the cold has had an effect?
At night time is when I hear it the most, but I don't know if it's because the rest of the house (and next door) are so quiet.