Error Handling

Error Status Query

Errors are queried using ReadByIdentifier (SID=0xB2) with Identifier=0x23.

Request:

7F 06 B2 23 17 46 40 03
│  │  │  │  │  │  └──┴─ Function ID (0x0340 = CombiGas)
│  │  │  │  └──┴─────── Supplier ID (0x4617 = Truma)
│  │  │  └───────────── Identifier (0x23 = ErrorStatus)
│  │  └──────────────── SID (0xB2 = ReadByIdentifier)
│  └─────────────────── PCI (0x06 = 6 bytes)
└────────────────────── NAD (0x7F = Broadcast)

Error Response Format

No Error:

01 06 F2 02 00 00 00 00
         │  │  │
         │  │  └─────── Error Code = 0 (none)
         │  └────────── Error Class = 0 (OK)
         └───────────── Format = 0x02

With Error (example W621H):

01 06 F2 02 06 15 3F F9
         │  │  │  └──┴─ Additional data (meaning unknown)
         │  │  └─────── Error Code = 0x15 (21 decimal)
         │  └────────── Error Class = 0x06 (6)
         └───────────── Format = 0x02

Error Code Decoding

The error code displayed on the Truma panel is composed from class and code:

Display Code = (Class * 100) + Code

Error Classification

Note: The actual W/E prefix on the display may follow Truma-specific rules that differ from this classification.

Suffix

• H = Heater (Combi)
• A = Aircon (Aventa/Saphir)

Polling Interval

The master polls ErrorStatus approximately every 800ms during normal operation.