Top-heat thermosyphon can transport heat without power input and many applications of it are expected. We built up an experimental set up of top-heat thermosyphon on a model house. The working fluid, water is warmed by solar irradiation in the thermal collector on the roof of the model house. The heat is transported to the heat exchanger which is set 4m lower than the thermal collector. In our experiment heat transported was oscillating and we could not observe unidirectional semi-stable flows which occur in a laboratory with constant heating.