Not a gret idea. 3 i. h! z3 D* I/ Z. \3 D* `" J; t6 S- @, V" z5 @
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.' f# k5 U$ k- ]' w1 C$ M
3 `5 A/ F# n2 _Beside,furnace hot water coil is made of metal. Some of it will come into the hot water.