Alde Heating System LIN Protocol

Frame Overview

Alde heating systems use LIN diagnostic protocol for discovery and standard frames for communication:

Frame Type	LIN ID	Purpose
Diagnostic Request	0x3C	Device discovery (Read By Identifier SID 0xB2)
Diagnostic Response	0x3D	Product identification response (RSID 0xF2)
Control Frame	0x1A	Send commands and setpoints
Info Frame	0x1B	Report status and temperatures

Device Discovery

Alde devices use the standard LIN diagnostic protocol (see LIN Protocols) for device identification.

Alde Product Identification

Diagnostic Request (0x3C):

NAD: 0x10
PCI: 0x06
SID: 0xB2 (Read By Identifier)
Identifier: 0x00 (Product Info)
Supplier ID: 0x41DE (little-endian: DE 41)
Function ID: 0x0001-0x0003 (little-endian)

Diagnostic Response (0x3D):

NAD: 0x10
PCI: 0x06
RSID: 0xF2 (positive response)
Supplier ID: 0x41DE (Alde manufacturer ID)
Function ID: 0x0001-0x0003 (Alde heater models)
Variant ID: Device-specific (e.g., 0x80)

Alde-Specific Values:

Supplier ID: 0x41DE (unique to Alde)
Function ID Range: 0x0001 - 0x0003 (Alde water heater models)
- 0x0001: Alde Compact 3020 series
- 0x0002: Alde 3030
- 0x0003: Alde 3030+
Node Address (NAD): 0x10

Control Frame (ID 0x1A)

Frame Layout:

Byte	0	1	2	3	4	5	6	7
Content	0x00	0x00	0x00	Control Byte 1	Control Byte 2	Control Flags	0xFF	0xFF
Purpose	Reserved	Reserved	Reserved	Zone 1 Temp + Gas	Zone 2 Temp + Power	System Flags	Reserved	Reserved

Bytes 0-2: Fixed Values

Always [00] [00] [00] - reserved/unused

Byte 3: Control Byte 1

Bit Range	Field	Values
0-5	Zone 1 temperature setting	Temp=(value × 0.5) + 5.0°C
6	Gas heating enable	0=Disabled, 1=Enabled (use propane/gas for heating)
7	Gas valve enable	0=Valve closed, 1=Valve open (enables gas flow to heater)

Temperature Formula: Range 5°C-30°C (0x00-0x32), Example: 19°C = 0x1C

Byte 4: Control Byte 2

Bit Range	Field	Values
0-5	Zone 2 temperature setting	Temp=(value × 0.5) + 5.0°C
6-7	Electric heating power level	Off=0, 1kW=1, 2kW=2, 3kW=3

Temperature Formula: Range 5°C-30°C (0x00-0x32), Example: 19°C = 0x1C

Byte 5: System Control Flags

Bit Range	Field	Values
0	Main panel on/off	0=Off, 1=On
3-4	Hot water heating mode	00=Off, 01=Normal, 10=Boost, 11=Auto
6	AC automatic mode	0=Manual, 1=Automatic

Bytes 6-7: Reserved

Fixed values [FF] [FF] - unused in current implementation.

Info Frame (ID 0x1B)

Frame Layout:

Byte	0	1	2	3	4	5	6	7
Content	Zone1 Temp	Zone2 Temp	Outdoor Temp	Control Byte 1	Control Byte 2	System Status	Reserved	Reserved
Purpose	Measured	Measured	Measured	Zone 1 Target + Gas Flags	Zone 2 Target + Electric Power	System flags	-	-

Byte 0: Zone 1 Current Temperature

Value Range	Temperature	Description
0x00-0xFA	-42°C to +83°C	Temperature = (value × 0.5) - 42.0°C
0xFB	< -42°C	Below sensor range
0xFC	> 83°C	Above sensor range
0xFD	–	No temperature sensor detected
0xFE	–	Not used
0xFF	–	Invalid reading

Byte 1: Zone 2 Current Temperature

Value Range	Temperature	Description
0x00-0xFA	-42°C to +83°C	Temperature = (value × 0.5) - 42.0°C
0xFB	< -42°C	Below sensor range
0xFC	> 83°C	Above sensor range
0xFD	–	No temperature sensor detected
0xFE	–	Zone unused/not installed
0xFF	–	Invalid reading

Note: Zone 2 is always present in the protocol frame but may indicate “unused” (0xFE) or “no sensor” (0xFD) on single-zone Alde units.

Byte 2: Outdoor Temperature

Value Range	Temperature	Description
0x00-0xFA	-42°C to +83°C	Temperature = (value × 0.5) - 42.0°C
0xFB	< -42°C	Below sensor range
0xFC	> 83°C	Above sensor range
0xFD	–	No temperature sensor detected
0xFE	–	Not used
0xFF	–	Invalid reading

Byte 3: Control Byte 1

Temperature Setpoint (Bits 0-5):

Value Range	Temperature Setting	Description
0x00-0x32	5°C - 30°C	Current setpoint
0x3B	< 5°C	Below minimum
0x3C	> 32°C	Above maximum
0x3D	–	Sensor error
0x3E	–	Unused
0x3F	–	Invalid

Status Bits (6-7):

Bit Range	Field	Description	Values
6	Gas Heating Status	Gas heating active	0=Inactive, 1=Active
7	Gas Valve Status	Gas valve state	0=Closed, 1=Open (gas flowing)

Byte 4: Control Byte 2

Same format as Byte 3 for Zone 2, plus:

Bit 6-7: Electric power level
- 00 = Off
- 01 = 1 kW
- 10 = 2 kW
- 11 = 3 kW

Byte 5: System Status Flags

Bit Position	Function	Values
Bit 0	Panel on	0=Off, 1=On
Bit 1	Panel busy	Communication status
Bit 2	Error present	0=OK, 1=Error condition
Bit 3-4	Water mode	00=Off, 01=Normal, 10=Boost, 11=Auto
Bit 5	AC input available	AC power status
Bit 6	AC Auto mode	Automatic operation
Bit 7	Pump running	Circulation pump active

Bytes 6-7: Reserved

Currently unused in this frame format.

Communication Example

Setting Zone 1 to 19°C, Zone 2 to 20°C, Gas On, Electric Power 2kW

Control Frame (0x1A):

[00] [00] [00] [0x5C] [0x9E] [0x01] [FF] [FF]
Byte 3: 0x5C = 19°C setpoint (0x1C) + Gas on (system-wide)
Byte 4: 0x9E = 20°C setpoint (0x1E) + Electric 2kW (system-wide)
Byte 5: 0x01 = Panel on

Reading Current Status

Info Frame (0x1B) Response:

[0x7A] [0xFE] [0x39] [0x62] [0x00] [0x81] [FF] [FF]
Byte 0: 0x7A = Zone 1 actual: 19°C
Byte 1: 0xFE = Zone 2 actual: Zone unused/not installed  
Byte 2: 0x39 = Outdoor: 15°C
Byte 3: 0x62 = Zone 1 setpoint: 22°C, Gas active
Byte 4: 0x00 = Zone 2 off
Byte 5: 0x81 = Panel on, Pump running