?" A+ _/ q: }5 }# }3 qHot water has went through all your home's internal pipes whereas cold water comes "direct" from your local reservoir. Which should be pretty safe. G, _" y) R" j/ ^! s+ \$ H: K # _0 l/ `7 y. U+ `Beside,furnace hot water coil is made of metal. Some of it will come into the hot water.