On Demand Hot Water Heater to save water

[Rbertalotto]

While waiting for hot water to reach the faucet, I seem to waste a lot of precious water when I'm boondocking. Has anyone installed an undersink, propane, on demand hot water heater?

Or some other way to return this unused water to the water tank?

[Bluepill]

Ideas:

Keep a container (Tupperware type is good) near the faucet to catch the cool water, then use it for hand washing, toilet flushing, etc.

At least one guy installed a two-way valve to re-direct the water back to the fresh tank.

[GaryE]

I have the Girard tankless water heater, I find if you run the hot water for about 3 - 5 seconds then turn it off. Let the water heater cycle. Open the faucet again and you should have hot water in a few seconds.