While it heats up water it starts driping from the repeat valve. Then if u turn on the water and replace the pressure it stops?

Repeat valve? Relief valve perhaps? Yes turning on the water reduces pressure. Have you ever checked house water pressure? Could be a bad main pressure reducing valve, one set too high or a bad PRV on the heater.

The T&P valve will Leak if either the water temperature is too high or if the water pressure to the house gets too high.

Check the water pressure and the temperature setting on your water heater, Also check if you have water pressure regulator installed, see the image.

John