Every now and then, I have an interruption in the supply of water from the city. In the past, I would simply notice there is no water provided, and that the water meter would stand still.
But I have recently installed myself an electrical water heater (a simple device of 200 L that contains water, and heats it), as a replacement for the previous gas water heater (that had a much lower volume, and was instantaneously heating the water).
Since then, when there is a water interruption, the water is leaving the water tank at a dramatic speed (I see my water meter turning very fast in the WRONG direction).
Should I be worried about this? Anything I should do?
EDIT: Upon further inspection, I was actually mistaken, and the water tank actually stayed full. The whole cold water circuit was emptied, and the water meter kept running because of strong air pressure. Suction from the supply side caused strong air pressure leaving my house's system. I am still confused as to how that could be.
Here's the system I have installed at the cold water entry point of my electrical water heater :
When the problem occurred I turned off the taps of cold and hot water in and out of the water tank. Effectively, this was removing the water tank and the vacuum breaker from the circuit entirely. And yet, the problem kept happening (air was still flowing strongly, going towards the supply). So I think this means it was not a problem with the water heater nor the device on the picture?