Yes, the temperature can be adjusted without the remote. Press and hold the heat icon on the fireplace insert (three wavy lines) for five seconds while the control panel is illuminated. The digital display will flash at half second intervals, signaling that the temperature can then be adjusted. By pressing on the the heat icon again, you can cycle through the settings. Once you've made your selection, the digital display will flash for an additional five seconds.
To learn more about working the fireplace features using both remote and control panel, you can watch a video by clicking here.