Hoping someone can please help. I have an intermittent fault with my electric hot water. I have an older style electric hot water service that heats on controlled load over night. The large tank is in roof space of 60s built villa unit. Every few mornings, no hot water will come out of shower. When this happens pressure is reduced at all other taps. A gurgling sound comes from the shower. I can get around it by turning on the cold full while hot tap is on. When I turn off cold, hot has come through. Plumber has replaced hot shower tap washer. Also reseated hot tap but problem persists. I have cleaned out the shower head. Other change is a doubling of my electricity usage in the last quarter. I think that the water temperature is hotter (now scolding) than before and bill suggests a change (hot water is my main electricity cost). Very happy to provide more information or answer questions as needed. Many thanks!