Boiling is not enough. U can't boil the rust out of the water. The water has been passing through pipes that is presumably decades old. Filtering is a better way to clean up ur water
Not to go too far off topic, but the difficulty of removing crap from water is why China is long-term fucked, with 80% or more of its groundwater sources polluted with heavy metals, industrial organic compounds, fertilizer runoff, oils, and also pharmaceutical compounds from farming, etc. Can't even trust the bottled water there.