Abstract: A water heating system for a concrete batching plant comprising a closed tank (1) having low heat transfer properties for containing the liquid to be heated, a heat exchanger having liquid carrying conduit means connected by conduits (2,3) to said tank (1), a first pump (3a) for circulating liquid from the tank (1) to the heat exchanger (4) while the liquid is being heated by said heat exchanger (4), a second pump for transferring the heating liquid from said tank to the concrete batching plant, control means for controlling the operation of said heat exchanger and said pumps and including means for monitoring the ambient temperature, the temperature of the water in the tank, the temperature of the water delivered from the tank, and the amount of water delivered from the tank, and a mixing valve for mixing cold water and/or recycled water with said heated water, said control means controlling the positioning of said mixing valve based on the temperature of the water in the tank and the temperature of the wate