Attwood furnace will not contnue heating

The sequence (Shortened to match your problem)

First: Attwood makes two different designs, One has a combination Thermocouple (Flame Sensor) Ignighter (Point) (the other point is ground) this carries about 1,000 volts during ignition and just under a half volt as flame sense on the same wire.. Imagine a switch failing and putting 1KV on the device deisgned to sens 1/2 volt and you have what I think happened to my control board.

Possible issues:

Bad burner adjustment, not getting hot enough (not likely but possible)
Obstructed flame/exhaust path (More likely)
Bad/dirty thermocouple Try cleaning it first.
Bad connection on one end or the other of the wire. (This would not bother the thousand volts but would the half volt) Disconnect and reconnect a few times.

Bad control board (DING DING DING) this is what happened to my furnace, a new board costs about 250 bucks (or rather did then) plus S&H, a new board from Dinosaur Boards, S&H included was less than 110 bucks (2 dollars less)

I opened the box.. I am a trained electronics technician, I was seriously impressed with the construction and workmanship, Way better than the OEM in my not very humble opinion, Several others have said the same thing. I have done a bit of electronics design and construction so I gave the board another look,, Sitting there on the component side is a neat little device, Might have cost as much as five cents in bulk but I doubt it.. I happen to know what it's for... It is to protect the flame sensor chip from the kilovolt (It clamps the voltage to 90, or possibly less depending what gas is in the tube). Appears Dino boards agrees with my theory of what went wrong.

Board fit, i did add a couple of zip ties to hold it in place since another of the improvements meant it might fall off the mounting bracket.

Recommendation: Rule out everything else before you spring for a new Dino board.

Ours was the circuit board when it kept going into lockout.

Are you sure all the air was out of the gas line I sometimes have to let it cycle through the 3 ties to light 4 or 5 times before all the air is out of the line.

thank you for the responses, any other experiences?

On my atwood water heater with the same issue, I replaced the ignitor very easy and it fixed the problem. It has to due with the feedback from the ignitor to the board. The ignitor seemed to work, but it did not give the proper feedback to the board.

Assuming no restriction in gas flow, look at the thermocouple for the problem. Easy to fix....