The performance of electric boiler using thick-film heater has been investigated experimentally. Electric boilers are using thick film heater is composed of four to a water chamber. In this study, the water flow rate while changing then umber of heaters and heating performance was evaluated. One water chamber, the average heat release is approximately 6.63kW. And average heat release of four water chamber is about 29.08kW. The energy efficiency of the water chamber 4 was 95.4%. Finally, the average heat release and energy-efficiency of electric boiler is increased with increasing water chamber number.