Close system:With close waterway design and built-in expansion water tank,the circulating hot water is totally isolated from atmospheric air, so it is hard to form scum and it can reduce the corruption of heat supply system.

• 闭式系统：闭式水路设计，内置膨胀水箱，供暖循环水与大气完全隔离，不易结水垢，对供暖系统的腐蚀小。