: y5 N0 d4 j7 n5 G* W% {2 AHot water has went through all your home's internal pipes whereas cold water comes "direct" from your local reservoir. Which should be pretty safe.3 ]0 b7 V7 ?: A. t# p
0 [7 O, d. `5 Y* S: T/ WBeside,furnace hot water coil is made of metal. Some of it will come into the hot water.