Not a gret idea. 5 }9 Y9 o' M) W $ @/ s7 }- ]6 u2 y/ q2 l9 g6 \ FHot water has went through all your home's internal pipes whereas cold water comes "direct" from your local reservoir. Which should be pretty safe. * [5 U7 z# _/ R: P5 o1 e0 e # I" M N% N: k4 i. V1 rBeside,furnace hot water coil is made of metal. Some of it will come into the hot water.