Both of the previous are great ideas. Also consider, if it is an older valve, that the main does not close completely, for a variety of possible reasons. We see that alot in older homes. You can confi ... read more
The above are two good, and siilar in approach answers, but there are two issues it seems no one includes:
1) If you house was built before 1978 it must be inspected by a certified contractor or lead ... read more