+ N' _8 M8 n) U* X5 R; B. M6 `- I2 OHot water has went through all your home's internal pipes whereas cold water comes "direct" from your local reservoir. Which should be pretty safe.6 E b/ z; D4 h) N% D: u
8 l8 s9 g# g, L2 {9 z/ L; {Beside,furnace hot water coil is made of metal. Some of it will come into the hot water.