The pressure relief valve keeps leaking. The h/w tank is about 9 months old.

The problem started when the main line broke. The township had to turn my water off and when they fixed it and turned the water back on is when it started. Any help towards a solution is always appreciated. :)

Is your water pressure higher than it normally was before the water main work? If your house pressure is high and then the water is heated, which makes it expand, the pressure can go above the valve rating and it WILL leak. In that case you may have to get a pressure reducing valve installed at your meter. Many times the water authority does that. Usually only when the pressure is above 60 psi or so.

Or possibly it got some dirt in it. Flip the little lever on it several times and let it snap shut. You will release a stream of water which should flush out any dirt on the seal. If it still leaks, it is most likely faulty. Is there a warranty?

Pressure Relieve Valve (PRV) is factory preset at 150 PSI. It will start leaking when water pressure approaches this setting.

If it leaks, it means that your Water Pressure Regulator (WPR) is not reducing water and as result, allows higher pressure into your house. You will have to replace both WPR and pressure relieve valve. It is a common problem...

Go to Home Depot, get exactly same WPR and buy new PRV. Install them...

OR if you have a sprinkler system with a check valve or backflow preventer installed and no expansion tank installed on the water heaters cold water supply then you have located the source of your problem. Now you have three explanations. 1)a faulty PRV valve. 2) excessive house pressure. **or** 3) hot water expansion.
Which door will it be? Door number one,two, or three? Good luck, n Tom

The First thing I will sugget to check your water pressure, use a water pressure test gauge see the Image below, second check your water heater selector the temp should be selected to 120 Degrees see the Image below, once you check get back to us, Thanks.

John