What's Wrong With This Picture? Double TPRV Valves

ANSWER: Double Trouble

I'm guessing the owner of this water heater appliance had heard of the dangers of overpressurizing water heaters and thought he had figured out a fix for his. In the absence of an extension pipe directing boiling water to within 6 inches of the floor, this configuration would direct it, who knows where?

Seriously, what you see is not a proper or safe configuration. Only one TPRV valve should be in use (never two), attached to a vertical extension pipe, directing any escaping steam or boiling water harmlessly to the floor or drain pan below.

It's one thing to be creative, it's another to be dangerous!

Take time to view this video on an exploding water heater under test conditions.