water heater won't stay lit

It's probably a similar concept as the Attwood if it's DSI. On my Attwood that ignitor probe that shoots the spark to the other side rod or terminal is also a flame sensor. It has a very small bend on the end of it and it has a single wire going up to the card. The spark shoots off that probe and the valve opens long enough for the flame to heat the probe. When the flame heats the probe slightly it sends a millivolt signal back though the same probe wire to tell the card YES stay on and continue sending current to the control valve. That's how my Attwood works. Do you know the model number? Try the terminals first and then get the model number.

I cleaned the sparker probe, I tried to fool it with a little extra heat from a small torch etc but no go. Shut it off and try removing and replugging in all the different connectors. Pay attention especially at the card for any corrosion. Be sure it's off if you start cleaning the terminal strip as you will cross feed voltage to where it dont belong.

Edit. OK got the model