Impacts of magnetic field and thermal radiation on Fe3O4-H2O nanofluid hydrothermal behavior are investigated. Constant heat flux condition is taken into account for inner wall. Innovative numerical method is chosen namely Control volume based finite element method. Influences of radiation parameter (Rd), Rayleigh (Ra), Hartmann (Ha) numbers and volume fraction of Fe3O4-H2O (phi) on hydrothermal treatment are shown graphically. Results reveal that impact of thermal radiation on convection heat transfer is more sensible for higher buoyancy forces. Thermal boundary layer thickness augments with rise of Rd, Ha while it reduces with rise of Ra, phi. Nanofluid velocity reduces with augment of Hartmann number but it enhances with augment of radiation parameter. (C) 2017 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.