Our unit has an Atwood heater, it did close to the same issue. When I tested my the control board had went out, we had our unit only 19 months. In the tool tab on top of the page you can find the manuals there.
Since our unit was out of the 1 year warranty I went back to the dealer for the replacement board, $190.00. Since Atwood has a 2 year warranty I called them and they said a "tech or dealer needs to call and explain the board is bad." When the dealer (Holman's in Cincinnati) called Atwood and explained Atwood sent them a replacement board to return to their stock. Once Holman's received the board they refunded our money.
Assuming your unit is new call Heartland with your vin#, Heartland has in the past for us authorized a mobile repair guy to come out and fix some issues. But with this you will pay the service call fees.
If your heater is an Atwood the control board is simple to remove, and maybe take to a dealer to bench test, if you need to.
Here is the manual link to troubleshot the Atwood
[FONT=Verdana,Arial,Tahoma,Calibri,Geneva,sans-serif]http://manuals.heartlandowners.org/manuals/Plumbing/Wtr_Heater/Atwood/Atwood%20Water%20Heater%20Service%20Manual.pdf[/FONT]