In the present work, the effect of temperature and solution pH on calcium carbonate precipitation from iron‐rich waters was investigated. Calcium carbonate was precipitated by CO2 removal. The increase in the temperature or the solution pH leads to the acceleration of calcium carbonate nucleation and crystal growth. Iron addition retards the formation of calcium carbonate crystals and enhanced the precipitation in the bulk solution. At high supersaturations, the inhibition effectiveness of iron is small and it could be improved by lowering the solution pH. The results of the present work show that it is possible to reduce or completely prevent scale formation in different water treatment processes by controlling the operating parameters which favourably affects the water treatment costs, increases the equipment life and allows increased product water recovery.