Atwood RV fault codes

Atwood (now part of Dometic) furnaces and water heaters are widespread in older and current RVs. Furnace control boards use a status light; water heaters typically lock out on repeated ignition failure.

Furnace

1 flash
One LED flash followed by a 3-second pause, repeating. I… 2 flashes
Two LED flashes followed by a 3-second pause, repeating.… 3 flashes
Three LED flashes followed by a 3-second pause, repeatin… 4 flashes
On a 2-stage Excalibur furnace control board, four flash… 5 flashes
On a 2-stage Excalibur furnace control board, five flash… Steady on (no flash)
The diagnostic LED on the ignition control board is on c…

Water Heater

DSI Fault / Lock-Out
On Atwood DSI (Direct Spark Ignition) water heaters ther… ECO open / tripped
The ECO is a backup high-limit temperature switch wired … Gas & spark, no flame proven
A diagnostic sub-condition of the DSI lock-out: both gas… Gas present, no spark
A diagnostic sub-condition of the DSI lock-out from the … No spark / no ignition
Dead unit with no spark at the electrode and no lockout-… Spark present, no gas
A diagnostic sub-condition of the DSI lock-out from the … TCO (thermal cut-off) tripped
Current Atwood DSI water heaters have a one-shot thermal…