Not a gret idea. $ e' D* h; j1 F5 r. `0 c 8 b% a9 W$ d5 ?3 B7 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.# b& ?' `4 m) p7 j9 ]. K! S' B
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Beside,furnace hot water coil is made of metal. Some of it will come into the hot water.