The Gas hot water system is an outdoor unit outside usually installed on the side of the property. It is about 1.8m height, a tank inside of the unit. There is a small door panel and there is a burner.
When hot water is used, the burner is on. When not in use, it is a small light (pilot light).
When you turn on the hot water, you can hear a loud noise to start.
On windy days, or for some reason the pilot light can be turned off which causes no hot water.
So one way to fix it is to restart the pilot light.
