Hello Bin,
If you have not done so already, it helps to drain the system at the lowest point. Meaning apply the shut off valve first, open the faucet at the lowest point (usually in the basement or ... read more
A lawyer is the first place to start. Your builder should be insured for problems like this. If it is a big box builder then I am sure something in the corporate contract has an answer for this. You d ... read more