Abstract: A device for heating chemical tanks includes at least one heat exchanger coil immersed inside a chemical tank. An inert gas, such as nitrogen, is heated and made to flow through the coil to heat a solution in the chemical tank to the desired temperature, which is sensed by a sensor. If microfractures form in the heat exchanger coil, the inert gas simply bubbles out of the solution and does not adversely impact the purity of the solution. In addition, the bubbling of the gas indicates the presence of a microfracture. A second heating coil is provided, and also provides heated inert fluid for heating the solution in the tank. The fluid flow through the first coil is controlled linearly to maintain the temperature at the desired temperature. The fluid flow through the second coil is controlled impulsively to quickly return the solution to the desired temperature after a temperature transient occurs, such as after a relatively cool object is immersed into the solution.