Not a gret idea. 2 Y- m9 [ B# |7 Y* K4 T% ~4 N + M: X" L+ L/ DHot water has went through all your home's internal pipes whereas cold water comes "direct" from your local reservoir. Which should be pretty safe.0 J+ g% p3 u" A) N
# R- T6 X9 H- I9 S. U7 H
Beside,furnace hot water coil is made of metal. Some of it will come into the hot water.