Something I tell all my Water Heater customer's or even Boiler customers
You have a relief valve on that heater, I am going to test it to make sure it open correctly
Sometimes they don't reseat properly so I am letting you know ahead of time that I may or may not have to replace it
if I can't get the (in this case) the Temperature and Pressure Relief Valve to reseat then I will have to change it.
If you don't want me to work on your water heater or boiler tell me in advance because I will do that test on all relief valves.
My Insurance company loves me......
The reason I mention this is the cobwebs that are on that water heater......Just wondering when the last service was on the water heater?