Recently, we noticed our hot water system seems to be have water dripping down from the pipe somewhere constantly.
Our hot water system is a Rheem Stella Gas Outdoor Water Heater.
Searched through the manual and it says: "it's normal and desirable this valve allows a small quality of water to escape during the heating cycle".
But the "valve" is on the other side of the system, the leaking is from the side where the hot/cold water pipes are connected, as shown below.
Not sure if this is normal, we contacted our builder's maintenance guy and 2 tradies arrived a few days later in the early morning. They have a quick look, use a big spanner to tighten the nuts above that blue thing and that stops the leak straight away. Too easy!