Burner shuts off after about 5 minutes

Check for error codes and service manual on following link:
http://waterheatertimer.org/How-to-troubleshoot-gas-water-heater.html#intellivent

Replace gas control valve
http://waterheatertimer.org/How-to-replace-Honeywell-gas-control-valve.html

Gene:

Water Heater Timers Save Money

If you need further help, I’m available over the phone at https://www.6ya.com/expert/gene_9f0ef4df2f9897e7

replace the 2 solenoids on the gas valve will solve the problem

Most likely the switch that controls that burner is the problem and needs replacing

Try changing the "stack flu sensor". It could be the sensor is bad or the sensor could be detecting a bigger problem. The sensor can not be jumped out.

What you hear is what's called a "Cold Burner". Turn the appliance OFF wait a couple of minutes and turn it back ON. If you can gradually turn the burner up, do so. The noise you heard should have stopped. If it didn't you may have a low gas pressure situation or the air intake valve on the burner needs cleaning and/or adjusting. If you are using propane gas, the tank may be very low on fuel, too.

Hope this helps you troubleshoot and solve the problem.

This system uses an electrical test to make sure that the burner is lit. The flame sensor will either be broken or will be covered in deposits (clean with an emery cloth).

The flame sensor is usually a small metal rod that would be in the direct line of fire of the burner with 1 wire attached.

CAUTION:

The ignitors can be very fragile and are expensive. They are very brittle, do not touch it.

Turn off the power to furnace.
on the last burner to light there is a small metal rod in front of the burner. This is a safety called the flame sensor. It is dirty. Unscrew it from the bar ( 1 Screw) unplug the connector wire from it and clean it with steel wool. it will be kind of burnt. Plut back in place and turn on the furnace to cycle.

Make sure that the thermocouple is well into the flame. Check to make sure the other end is secure into the gas valve. Check for any poor connection both gas and electric. If the LP cylinder is icing up, it is a vaporizing problem and the heater is sucking the available gas out of the cylinder faster than it can vaporize. You will need a larger cylinder.

the flame sencer window my need cleaning

Kenny did you change the thermo coupler?