空调下水管堵塞如何疏通?

空调有两路下水,一路到洗手间,一路到屋檐.屋檐漏水哗啦哗啦的,一定是主下水什么地方不对.

拆开洗手间下面的管子,黑皮管里还干净,那么如何疏通上面连接的PVC呢?

1）liquid plumber? from the vent hole in the main drain

2) compressed air?

3) snake?

Any suggestions?

Thanks,

Here is what Google said:

http://www.dannylipford.com/video/ac-drain-clean-out/#tabs-1

http://frugaldad.com/2008/05/20/diy-project-2-unclogging-an-air-conditioner-drain/

http://answers.yahoo.com/question/index?qid=20080729070028AAxsdnu