In some cases, plumbing repairs may be required prior to meter installation. If defective plumbing, inoperative shut off valves or deteriorated pipes prevent meter replacement, you will be required to hire a licensed plumber to make the necessary repairs. A fully functioning main shut off valve before the water meter, knowing the location and how to operate this valve is an absolute must for homeowners and household members. The main valve is the one to stop most plumbing catastrophes, such as a burst pipe. If your main shut off valve does not work you must replace it.