Help with Atwood GCH10A-4E intermittent fault

[BVThunder]

Haven't used propane side of water heater in several years. Using it now because the campground where we are staying charges for electricity.

Having intermittent fault light issues. Water heater will light, heat up and shut off when thermostat is satisfied. Will relight when hot water is used or when thermostat calls for reheating.

Problem is that the fault light will come on anywhere between an hour to several hours and shut down the heater. Longest time without a fault has been about 8 hours. The shortest is an hour or less. I can turn the heater off for a few minutes and relight it. Then the intermittent failure will repeat. This has been going on for four days.

Tank is 42% full. Both gas furnaces are functioning properly. So, supply or air in the line is not the issue. Anybody got a clue?

[Old-Biscuit]

Haven't used Gas in years.....therefore the GAS side hasn't been cleaned
Burner tube
Orifice
Spark Electrode.....very important
Connectors on circuit board

Just need to do some 'house cleaning' to resolve the issue

Spark electrode.......remove & clean tip with emery cloth
Make sure wire connector makes a tight connection on Transformer terminal
(soot/carbon will inhibit milliamp flame proving return to circuit board)

Burner tube...remove & clean it out (spider webs can cause air/fuel mixture problems)

Orifice.......remove/soak in alcohol/air dry....no poking anything thru or blowing high pressure air thru it

Connectors on circuit board..........6 pin has both ground pins (grounds very important) and 4 pin carries initial DC to circuit board