I've been RVing for 30+ years, 3 motorhomes (first was a pilot type WH, 2nd & 3rd DSI type). Only failure of a WH occurred on my first, a non-DSI type, and it was solved with a control board. Occasionally, I get an ignition failure; I simply turn it off and back on, and it lights up. Methinks something else is going on.
To the OP; what do you mean by "DSI fault"? If mine fails to ignite, the LED next to the switch comes on (indicating an ignition failure). Turning it off and back on usually solves it and the WH is back in business. I do know that on my 2nd RV, after sitting unused for awhile, I sometimes had to try it several times simply because it took a bit to get LPG through the lines to the unit (same with the fridge); running a burner or two on the stove sped the process up.
