♦ How to determine the best location to install a Bridge Valve:
Bridge Valves should be installed under the kitchen or bathroom sink furthest from the water heater. In the illustration below the Bridge Valve is installed under the sink on the right which is the furthest from the water heater.
Once hot water reaches the last fixture hot water will be available at every other fixture that is fed by the same hot water line. Additional Bridge Valves can be installed under other sinks as well but at least 1 should be installed under the furthest sink.
In the illustration below there are 2 dead end lines which requires 2 Bridge Valves. A second Bridge Valve is required for the upstairs fixtures.
Help understanding your plumbing layout can be found here: Determining Plumbing Layout