Not a gret idea.& T! ~0 p* {: L
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Hot water has went through all your home's internal pipes whereas cold water comes "direct" from your local reservoir. Which should be pretty safe. + C& \; j9 p" e, p7 ?+ e9 r9 J8 I # u( z5 K; g6 k c3 T' c9 DBeside,furnace hot water coil is made of metal. Some of it will come into the hot water.