Polyacrylic acid (PAA) is synthesized from acrylic acid. Different concentrations ranging from 20 to 100 ppm of PAA in water are used as an antiscaling agent on copper and mild steel (m. s.) for 4 to 24 h. The deposition of salt decreases with increasing concentration of PAA as well as with increasing time. The zero acid value of PAA is observed after refluxing for 24 h. The concentration of PAA had no effect on the heat transfer coefficient and the heat transfer rate of the shell and tube heat exchanger. When varying the amount of PAA from 20 to 100 ppm in water, a negligible change in viscosity is observed which does not effect the flow behaviour of water in heat exchanger.