http://home.howstuffworks.com/home-improvement/heating-and-cooling/how-to-troubleshoot-a-hot-water-and-steam-distribution-system3.htm
也有可能是别的原因。找个plumber 检查一下。
• 多谢 -mojito- ♀ (0 bytes) () 12/21/2016 postreply 12:34:40