Not a gret idea.7 i! M1 ?4 s( K& r9 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., b9 `% @# P" l$ I* f# @
5 t9 U4 m- t4 B" OBeside,furnace hot water coil is made of metal. Some of it will come into the hot water.