Reliable, low-cost energy storage solutions are needed to manage variability, pro-vide reliability, and reduce grid-infrastructure costs. Redox flow batteries (RFB) area grid-scale storage technology that has the potential to provide a range of services.Desirable characteristics are long cycle life, high efficiency, and high energy density.A key challenge for aqueous redox flow battery systems is thermal sensitivity. Oper-ating temperature impacts electrolyte viscosity, species solubility, reaction kinetics,and efficiency. Systems that avoid the need for active thermal management whileoperating over a wide temperature range are needed. A promising RFB chemistry isiron-vanadium because of the use of low-cost iron. This is an analysis of the thermalresponse of on Iron-Vanadium (Fe/V) RFB using a zero-dimensional electrothermalmodel. The model accounts for the reversible entropic heat of the electrochemicalreactions, irreversible heat due to overpotentials, and the heat transfer between thestack and environment. Performance is simulated using institutional load data forenvironmental conditions typical of Canadian jurisdictions.