% B9 g- R( p& |% o4 O% b% bHot water has went through all your home's internal pipes whereas cold water comes "direct" from your local reservoir. Which should be pretty safe. & r/ X4 m4 O' n( g - ?6 r' t z% l5 |( }, T5 WBeside,furnace hot water coil is made of metal. Some of it will come into the hot water.