Do not put the heating tube in the water shortage of the towel rack

Do not use the heating tube in a heating container that lacks water and is dirty. Put the heating tube in a liquid with more impurities to heat it, which is easy to cause the surface to be scaled and the heat generated by itself cannot be dissipated in time. lead to damage to the heating tube, and at the same time ensure that the heating liquid shall not be lower than the normal liquid level standard, otherwise it may also damage the heating tube and cause fire and other dangers;