Okay, I knew the switch and I turned it on. But I went into the bathroom that was attached just a bit further away from the heater. But the water didn't come hot. I mean, it couldn't fill hot water. So I thought that the heater is not functioning properly. I had faint notice that pipe was actually just below the heater outside. So I got the bucket. And when I tested, I got hot water. So I filled the bucket with hot water