I have a richmond power vent water heater model number 6G40POW-40F.It will run for 2 min then shut itself off then restart and do the same thing all over.Then 2 lights come on and it wont run. Any help with this? Why is it doing this? how can i solve this fast?

Fastest way to solve water heater problem is call plumber or service technician.

Open following link for typical error codes for intellivent gas valve found on newer Richmond/Rhemm power-vent gas water heaters:
http://waterheatertimer.org/pdf/Intelli-vent-gas-valve2.pdf
http://waterheatertimer.org/pdf/Intellivent-service-manual.pdf

There is no 100% sure way for novice to repair gas water heater.
This is because electrical parts have to ohm-tested using information from service manual that is typically not sent with new water heater.
Also parts have to be cleaned. The gas pressure checked, air in gas line removed, burner tubes and pilot tube and combustion chamber cleaned, burner parts inspected for problems, air intake cleaned, exhaust vent tested.
http://waterheatertimer.org/How-to-install-gas-water-heater.html#troubleshoot

Best way for do-it-yourselfer to solve water heater problems is to learn as much as possible about specific model by reading product manual that comes with new heater.
The manual will show error codes.
Then keep up with yearly service recommendations shown in manual.