Here's mine :

BYTE wb_io(BYTE cmd, BYTE skip)
{
    byte error;
    byte tries = 3;
    do
    {
        msg_send(cmd);
        error = msg_recv(cmd, skip);
        if (!error) return 0;
        retries++;
        if (error == ERROR_TMO_CHK_ADR) {
            wait_ms(ERROR_DELAY);
        } else if (error == ERROR_NACK) {
            wait_ms(NACK_DELAY);
        } else {
            return error;
        }
    } while (--tries);
    return error;
}

void Do_Errors(byte clear) {
    byte errors;
    BlinkPush();
    DoBlink(0x11,0);
    message_length=1;
    message_data[0]=1; // Get errors
    if (!wb_io(0x56, 1)) { // Error Cmd
        errors=message_in[0];
        if (errors && clear) { // Are there any errors?
            message_data[0]=3; // Clear errors
            if (!wb_io(0x56, 1)) { // Error Cmd
                Blink_Number(errors); // We cleared errors
            }
        } else Blink_Number(errors);
    } 
    BlinkPop();
}

It includes my blinky stuff so it reads any errors from the heater, and if the clear flag is set and the heater has errors it clears them. Otherwise it just flashes out the number of errors.

Only tested on my D3 ThermoTop V, but it works here.