[Carl n Susan]

With a 2017 you should still be under warranty. Calling Suburban would be my 1st choice.

I don't understand your description. You wrote " the hot water heater will not light. It will try to light but no go.." and followed with "It turns on and runs for 5-10 seconds and shuts off.". There is nothing that "runs" on the gas side. Are you saying you can hear it sparking but the gas does not ignite (you have to be outside with the door off to really tell)?? If so it could (will) be one of the gas valve solenoid coils has failed. Do a Search on "solenoid valve" and you will see some previous discussions on this failure. Here are two:
http://www.montanaowners.com/forums/...ad.php?t=45772
http://www.montanaowners.com/forums/...ad.php?t=56211

Be aware that you don't have to replace the entire gas valve (~$100) if just the coil has failed. There is a link to a coli replacement (~$9) in one of the links

In the Files Section is a Suburban Water Heater Troubleshooting Manual. http://www.montanaowners.com/forums/downloads.php?do=file&id=17 It should help find the problem if it is a coil or not. .