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Boiler / heating system controller · Modbus register map
Buderus Logamatic 5000 boiler and system controller (Modbus TCP, datapoint list 4.0) Modbus register map
Updated 24 October 2026
The Logamatic 5000 series is Buderus' commercial boiler and heating-system controller, with a Modbus TCP server on its LAN 1 port. A BMS can send a flow-temperature or output demand to the boiler strategy, set heating-circuit and hot-water setpoints, and read outdoor, system, circuit and per-boiler temperatures, output, pressure and HMI status. This map covers the master controller's system, strategy, cascade, DHW 1, heating circuits 00-01 and boiler 1 points.
This page lists 109 Modbus registers for the Buderus Logamatic 5000 boiler and system controller (Modbus TCP, datapoint list 4.0) — 26 writable — with the table, 0-based wire address, data type, word order, scale, units and access of each, re-typed from Buderus’s own free documentation (linked below) and checked against it.
- Manufacturer
- Buderus
- Model
- Logamatic 5000 boiler and system controller (Modbus TCP, datapoint list 4.0)
- Equipment type
- Boiler / heating system controller
- Registers
- 109 (26 writable)
- Transport
- Modbus TCP
- Default unit ID
- 255
- TCP port
- 502
- Documented addressing
- 0-based (the number printed is the address on the wire)
- 32-bit word order
- ABCD high word first (big-endian)
- Firmware
- Logamatic 5000 firmware 1.3 or later; datapoint list product version 4.0 (2026-01-20)
- Also known as
- Logamatic 5313, Logamatic 5311, Bosch Control 8313, Bosch Control 8311, Control 8000, BCT 531, Logamatic 5000 Modbus
Integration notes: Buderus Logamatic 5000 boiler and system controller (Modbus TCP, datapoint list 4.0)
On the controller set LAN 1 to Modbus TCP/IP, turn on Modbus communication, write access and extended monitor data, then poll the controller at port 502, unit ID 255. To make it fire, write 1 to holding 402, the flow setpoint (°C) to 400 and 7 to the strategy bit block 405; read outdoor 0, system flow 4, boiler 1 flow 8001 and status 8012/8013.
Minimum registers to map
Addresses are 0-based wire addresses. Enough to monitor and run the unit; map more as the job needs.
| Register | Name | Type | Why | Access |
|---|---|---|---|---|
| HR 402 | Heat generator operating mode | UINT16 | Heat generator operating mode (on/off) | Read/write |
| HR 400 | System flow temperature setpoint | UINT16 | System flow temperature setpoint | Read/write |
| HR 405 | Strategy bit block | BITMAP16 | Strategy bit block (temperature- or output-led) | Read/write |
| HR 0 | Heartbeat (in) | UINT16 | Heartbeat counter | Read/write |
| IR 0 | Outdoor temperature | INT16 | Outdoor temperature | Read |
| IR 4 | System flow temperature | INT16 | System flow temperature | Read |
| IR 5 | System HMI status | UINT16 | System HMI status | Read |
| IR 8001 | Boiler 1 flow temperature | INT16 | Boiler 1 flow temperature | Read |
| IR 8013 | Boiler 1 status bits | BITMAP16 | Boiler 1 status bits (burner on, faults) | Read |
| IR 476 | Fault register 1 | UINT32 ABCD | Fault register 1 (message key) | Read |
Enable Modbus control & writes
Service menu > Connectivity: Local Area Network = Modbus TCP/IP (factory: Internet); Modbus communication = with or without heartbeat ('No' disables Modbus); Allow write access = On; Provide extended monitor data = On (factory Off, required for Modbus data). Then Service menu > Heat generation > Strategy data > Basic settings: enable 'Heat demand via Modbus' (and disable 'Internal heat demand' for exclusive BMS control).
Communication loss & watchdog
With 'Modbus communication = with heartbeat', the BMS must keep writing a changing counter to holding 0; holding 1 echoes it. If no new value arrives within the timeout (120-600 s, default 180 s) the controller raises a 'connection to building management faulty' message. 'Without heartbeat' disables loss detection.
Byte order & addressing
- Addresses in the list are already 0-based wire addresses; add 30001/40001 only if your BMS uses Modicon notation.
- 32-bit values (starts, operating time, fault keys) are high word first; some BMSs read the unsigned fault keys as negative signed values.
- The display code at 8019 is two ASCII characters packed into one register.
- Temperature demand (400) is whole degrees while most temperatures read back are x10.
Network setup
- Connect LAN 1 on the BCT 531 module to the BMS network; do not use the 172.31.42.x range, which the controller uses internally.
- Set a static IP (or DHCP) in the Connectivity menu and save.
- The unit ID is 255 by default; the guide says it can be changed from firmware 1.5.13 (the download page says 1.6).
- Firmware below 1.3 uses an older address list; a compatibility mode for firmware below 1.3.6 exists but should only be enabled for existing old integrations.
Watch out for
- The strategy bit block must include the lead-boiler bit (bit 0) from firmware 1.3.3, and with an FM-CM cascade module the lead-boiler function must be enabled.
- Output-led demand (401) works only in exclusive mode (internal heat demand off) and only when all boilers on the controller are the same type.
- Points for hardware that is not fitted still answer, with invalid values such as 0 °C; writes to them are accepted but have no effect.
- A boiler in lockout or manual mode ignores heat demand until it is ready again.
Buderus Logamatic 5000 boiler and system controller (Modbus TCP, datapoint list 4.0) Modbus registers
Address = 0-based wire address (the documented number is shown under it when it differs) · Order: ABCD = high word first, CDAB = low word first · Scale: engineering value = raw × scale.
| Table | Address | Name | Description | Type | Order | Scale | Units | Access | Values / bits |
|---|---|---|---|---|---|---|---|---|---|
| IR | 0 | Outdoor temperature | INT16 | × 0.1 | °C | Read | |||
| IR | 1 | Damped outdoor temperature | INT16 | × 0.1 | °C | Read | |||
| IR | 4 | System flow temperature | INT16 | × 0.1 | °C | Read | |||
| IR | 5 | System HMI status | Overall controller status. | UINT16 | Read | 0 = Unknown; 1 = Warning; 2 = Fault; 3 = OK; 4 = Not active; 5 = Critical; 6 = No info | |||
| IR | 8 | Activated functions 1 | Which heating circuits and functions are configured. | BITMAP16 | Read | bit 0 = Heating circuit 00 (central module); bit 1 = Heating circuit 01; bit 2 = Heating circuit 02; bit 3 = Heating circuit 03; bit 4 = Heating circuit 04; bit 5 = Heating circuit 05; bit 6 = Heating circuit 06; bit 7 = Heating circuit 07; bit 8 = Heating circuit 08; bit 9 = DHW 1 (central module); bit 10 = DHW 2 (FM-MW); bit 11 = Alternative heat generator; bit 12 = CHP; bit 13 = FM-SI; bit 14 = Bypass desalination module; bit 15 = Solar | |||
| IR | 15 | DHW 1 charge pump | UINT16 | Read | 0 = Stopped; 1 = Starting; 2 = Running; 3 = Off; 4 = Fault | ||||
| IR | 16 | DHW 1 circulation pump | UINT16 | Read | 0 = Stopped; 1 = Starting; 2 = Running; 3 = Off; 4 = Fault | ||||
| IR | 17 | DHW 1 hydraulic status | UINT16 | Read | 0 = Fault; 1 = Not active; 2 = Off; 3 = Anti-seize run; 4 = Heating | ||||
| IR | 18 | DHW 1 thermal disinfection status | UINT16 | Read | 0 = Off; 1 = On; 2 = Completed; 3 = Fault | ||||
| IR | 19 | DHW 1 HMI status | UINT16 | Read | 0 = Unknown; 1 = Warning; 2 = Fault; 3 = OK; 4 = Not active; 5 = Critical; 6 = No info | ||||
| IR | 20 | DHW 1 temperature setpoint | INT16 | × 0.1 | °C | Read | |||
| IR | 21 | DHW 1 temperature | INT16 | × 0.1 | °C | Read | |||
| IR | 87 | HC 00 room temperature setpoint | INT16 | × 0.1 | °C | Read | |||
| IR | 88 | HC 00 room temperature | INT16 | × 0.1 | °C | Read | |||
| IR | 89 | HC 00 flow temperature setpoint | INT16 | × 0.1 | °C | Read | |||
| IR | 90 | HC 00 flow temperature | INT16 | × 0.1 | °C | Read | |||
| IR | 91 | HC 00 mixing valve output | Actuator modulation. | UINT16 | % | Read | |||
| IR | 92 | HC 00 pump modulation | UINT16 | % | Read | ||||
| IR | 93 | HC 00 active operating mode | UINT16 | Read | 0 = Manual setback; 1 = Manual heating; 2 = Holiday; 3 = Auto setback; 4 = Auto heating | ||||
| IR | 94 | HC 00 HMI status | UINT16 | Read | 0 = Unknown; 1 = Warning; 2 = Fault; 3 = OK; 4 = Not active; 5 = Critical; 6 = No info | ||||
| IR | 95 | HC 00 hydraulic status | UINT16 | Read | 0 = Fault; 1 = Not active; 2 = Off; 3 = Anti-seize run; 4 = Heating; 5 = Pump overrun | ||||
| IR | 99 | HC 01 room temperature setpoint | INT16 | × 0.1 | °C | Read | |||
| IR | 100 | HC 01 room temperature | INT16 | × 0.1 | °C | Read | |||
| IR | 101 | HC 01 flow temperature setpoint | INT16 | × 0.1 | °C | Read | |||
| IR | 102 | HC 01 flow temperature | INT16 | × 0.1 | °C | Read | |||
| IR | 103 | HC 01 mixing valve output | Actuator modulation. | UINT16 | % | Read | |||
| IR | 104 | HC 01 pump modulation | UINT16 | % | Read | ||||
| IR | 105 | HC 01 active operating mode | UINT16 | Read | 0 = Manual setback; 1 = Manual heating; 2 = Holiday; 3 = Auto setback; 4 = Auto heating | ||||
| IR | 106 | HC 01 HMI status | UINT16 | Read | 0 = Unknown; 1 = Warning; 2 = Fault; 3 = OK; 4 = Not active; 5 = Critical; 6 = No info | ||||
| IR | 107 | HC 01 hydraulic status | UINT16 | Read | 0 = Fault; 1 = Not active; 2 = Off; 3 = Anti-seize run; 4 = Heating; 5 = Pump overrun | ||||
| IR | 265 | Pending fault count | Number of messages currently pending. | UINT16 | Read | ||||
| IR | 363 | Cascade total output | Total boiler output. | UINT16 | kW | Read | |||
| IR | 364 | Cascade output under control | UINT16 | kW | Read | ||||
| IR | 365 | Cascade actual output | UINT16 | kW | Read | ||||
| IR | 366 | Cascade HMI status | UINT16 | Read | 0 = Unknown; 1 = Warning; 2 = Fault; 3 = OK; 4 = Not active; 5 = Critical; 6 = No info | ||||
| IR | 367 | Cascade demand mode | UINT16 | Read | 0 = Off; 1 = Temperature-led; 2 = Integral; 3 = Temperature- and output-led; 4 = Output-led | ||||
| IR | 384 | System return temperature | INT16 | × 0.1 | °C | Read | |||
| IR | 385 | System / low-loss header flow temperature | INT16 | × 0.1 | °C | Read | |||
| IR | 386 | Strategy HMI status | UINT16 | Read | 0 = Unknown; 1 = Warning; 2 = Fault; 3 = OK; 4 = Not active; 5 = Critical; 6 = No info | ||||
| IR | 387 | Strategy actual output | UINT16 | % | Read | ||||
| IR | 388 | Energy source | UINT16 | Read | 0 = Alternative heat generator; 1 = Cascade; 2 = External heat | ||||
| IR | 389 | Header temperature boost | Temperature raise applied at the header. | INT16 | × 0.1 | °C | Read | ||
| IR | 390 | Heat demand source | UINT16 | Read | 0 = Not active; 1 = Controller; 2 = Internal; 3 = Manual operation; 4 = External; 5 = Internal + external | ||||
| IR | 391 | Strategy flow setpoint | Active flow temperature setpoint. | INT16 | × 0.1 | °C | Read | ||
| IR | 392 | Strategy output setpoint | UINT16 | % | Read | ||||
| IR | 393 | Strategy operating mode | UINT16 | Read | 0 = Off; 1 = Heat absorption; 2 = Heat delivery | ||||
| IR | 394 | Strategy status bits | BITMAP16 | Read | bit 0 = External heat detected; bit 1 = Frost protection active; bit 2 = Priority requested; bit 3 = Lead requested; bit 4 = Flow temperature control requested; bit 5 = Output control requested; bit 6 = External heat demand | ||||
| IR | 395 | Maximum requested flow temperature | INT16 | °C | Read | ||||
| IR | 422 | Heat output | Delivered heat output. | INT16 | × 0.1 | kW | Read | ||
| IR | 423 | Gas input (Hi) | Gas consumption rate on net calorific value. | INT16 | × 0.1 | kW | Read | ||
| IR | 425 | Electrical power | UINT16 | W | Read | ||||
| IR | 476 | Fault register 1 | Message key; decode with Buderus' message-key list. | UINT32 | ABCD | Read | |||
| IR | 478 | Fault register 2 | Message key; decode with Buderus' message-key list. | UINT32 | ABCD | Read | |||
| IR | 480 | Fault register 3 | Message key; decode with Buderus' message-key list. | UINT32 | ABCD | Read | |||
| IR | 482 | Fault register 4 | Message key; decode with Buderus' message-key list. | UINT32 | ABCD | Read | |||
| IR | 8000 | Boiler 1 type | UINT16 | Read | 0 = None; 1 = EMS; 2 = SAFe; 3 = Add-on burner; 4 = Slave | ||||
| IR | 8001 | Boiler 1 flow temperature | INT16 | × 0.1 | °C | Read | |||
| IR | 8002 | Boiler 1 flow temperature rate of change | INT16 | × 0.1 | K/min | Read | |||
| IR | 8003 | Boiler 1 return temperature | INT16 | × 0.1 | °C | Read | |||
| IR | 8004 | Boiler 1 actual output | UINT16 | % | Read | ||||
| IR | 8005 | Boiler 1 load limit | Output limit currently applied. | UINT16 | % | Read | |||
| IR | 8006 | Boiler 1 operating temperature | INT16 | × 0.1 | °C | Read | |||
| IR | 8007 | Boiler 1 maximum output | UINT16 | kW | Read | ||||
| IR | 8008 | Boiler 1 minimum output | UINT16 | % | Read | ||||
| IR | 8009 | Boiler 1 burner type | UINT16 | Read | 0 = Modulating; 1 = Single-stage; 2 = Two-stage | ||||
| IR | 8010 | Boiler 1 fuel type | UINT16 | Read | 0 = Gas; 1 = Oil | ||||
| IR | 8011 | Boiler 1 maximum flow temperature | UINT16 | °C | Read | ||||
| IR | 8012 | Boiler 1 HMI status | UINT16 | Read | 0 = Unknown; 1 = Warning; 2 = Fault; 3 = OK; 4 = Not active; 5 = Critical; 6 = No info | ||||
| IR | 8013 | Boiler 1 status bits | BITMAP16 | Read | bit 0 = Controllable; bit 1 = Forced flow; bit 2 = Keep-warm function; bit 3 = Blocked by contact; bit 4 = Blocked by negative setpoint step; bit 5 = Burner on; bit 6 = Lead requested; bit 7 = Priority requested; bit 8 = Flow control requested; bit 9 = Output control requested; bit 10 = Locking fault; bit 11 = Blocking fault; bit 12 = Service message pending | ||||
| IR | 8014 | Boiler 1 requested mode | UINT16 | Read | 0 = Off; 1 = Heat absorption; 2 = Heat delivery | ||||
| IR | 8015 | Boiler 1 requested setpoint temperature | UINT16 | °C | Read | ||||
| IR | 8016 | Boiler 1 output setpoint | UINT16 | % | Read | ||||
| IR | 8017 | Boiler 1 water pressure | INT16 | × 0.1 | bar | Read | |||
| IR | 8018 | Boiler 1 fault code | Numeric fault code from the boiler. | UINT16 | Read | ||||
| IR | 8019 | Boiler 1 display code | Two ASCII characters, high byte first (12880 reads as 2P). | STRING[2] | Read | ||||
| IR | 8020 | Boiler 1 cascade start index | Position 1-16 in the cascade start order. | UINT16 | Read | ||||
| IR | 8021 | Boiler 1 burner starts | INT32 | ABCD | Read | ||||
| IR | 8023 | Boiler 1 operating time | INT32 | ABCD | min | Read | |||
| IR | 8025 | Boiler 1 valve position | UINT16 | % | Read | ||||
| IR | 8026 | Boiler 1 pump modulation | Boiler circuit pump modulation. | UINT16 | % | Read | |||
| IR | 8027 | Boiler 1 high-limit (STB) temperature | INT16 | × 0.1 | °C | Read | |||
| IR | 8028 | Boiler 1 flue gas temperature | INT16 | × 0.1 | °C | Read | |||
| HR | 0 | Heartbeat (in) | BMS writes a changing counter here when heartbeat monitoring is on. | UINT16 | Read/write | ||||
| HR | 1 | Heartbeat (out) | Echo of the last heartbeat value written. | UINT16 | Read | ||||
| HR | 7 | DHW 1 manual mode | Setback or heating when DHW 1 is in manual. | UINT16 | Read/write | 0 = Manual setback; 1 = Manual heating | |||
| HR | 8 | DHW 1 operating mode | UINT16 | Read/write | 0 = Auto; 1 = Manual | ||||
| HR | 10 | DHW 1 setpoint, auto heating | Range 20-90 °C. | UINT16 | × 0.1 | °C | Read/write | ||
| HR | 11 | DHW 1 setpoint, auto setback | Range 20-90 °C. | UINT16 | × 0.1 | °C | Read/write | ||
| HR | 12 | DHW 1 setpoint, manual heating | Range 20-90 °C. | UINT16 | × 0.1 | °C | Read/write | ||
| HR | 57 | HC 00 operating mode | Heating circuit 00 (central module). | UINT16 | Read/write | 0 = Auto; 1 = Manual | |||
| HR | 58 | HC 00 manual mode | Setback or heating when the circuit is in manual. | UINT16 | Read/write | 0 = Manual setback; 1 = Manual heating | |||
| HR | 59 | HC 00 room setpoint, auto heating | Range 5-35 °C. | UINT16 | × 0.1 | °C | Read/write | ||
| HR | 60 | HC 00 room setpoint, auto setback | Range 5-35 °C. | UINT16 | × 0.1 | °C | Read/write | ||
| HR | 61 | HC 00 room setpoint, manual heating | Range 5-35 °C. | UINT16 | × 0.1 | °C | Read/write | ||
| HR | 62 | HC 00 room setpoint, manual setback | Range 5-35 °C. | UINT16 | × 0.1 | °C | Read/write | ||
| HR | 63 | HC 00 holiday setpoint | Range 5-35 °C. | UINT16 | × 0.1 | °C | Read/write | ||
| HR | 64 | HC 00 offset | Range -15 to +15 K. | INT16 | × 0.1 | K | Read/write | ||
| HR | 70 | HC 01 operating mode | Heating circuit 01. | UINT16 | Read/write | 0 = Auto; 1 = Manual | |||
| HR | 71 | HC 01 manual mode | Setback or heating when the circuit is in manual. | UINT16 | Read/write | 0 = Manual setback; 1 = Manual heating | |||
| HR | 72 | HC 01 room setpoint, auto heating | Range 5-35 °C. | UINT16 | × 0.1 | °C | Read/write | ||
| HR | 73 | HC 01 room setpoint, auto setback | Range 5-35 °C. | UINT16 | × 0.1 | °C | Read/write | ||
| HR | 74 | HC 01 room setpoint, manual heating | Range 5-35 °C. | UINT16 | × 0.1 | °C | Read/write | ||
| HR | 75 | HC 01 room setpoint, manual setback | Range 5-35 °C. | UINT16 | × 0.1 | °C | Read/write | ||
| HR | 76 | HC 01 holiday setpoint | Range 5-35 °C. | UINT16 | × 0.1 | °C | Read/write | ||
| HR | 77 | HC 01 offset | Range -15 to +15 K. | INT16 | × 0.1 | K | Read/write | ||
| HR | 400 | System flow temperature setpoint | Heat demand for temperature-led control, whole degrees 0-120. | UINT16 | °C | Read/write | |||
| HR | 401 | System output setpoint | Heat demand for output-led control, 0-100 %. | UINT16 | % | Read/write | |||
| HR | 402 | Heat generator operating mode | Off stops the heat generators; consumers stay under control. | UINT16 | Read/write | 0 = Off; 1 = On (operation) | |||
| HR | 405 | Strategy bit block | Write 7 for temperature-led or 9 for output-led demand. | BITMAP16 | Read/write | bit 0 = Lead boiler; bit 1 = Prioritisation; bit 2 = Temperature-led control active; bit 3 = Output-led control active |
Notes on this map
- Download page: https://www.buderus.de/de/unternehmen/5000-modbus-9710 (public). The ZIP holds the Excel datapoint list, the German user guide and a message-key list. The page also states Modbus TCP port 502 and default unit ID 255.
- Scaling: registers marked 'x10' in the list are divided by 10 (scale 0.1). Setpoints without that mark (e.g. system flow setpoint 400) are whole units.
- Types follow the list: 'int' (0-65535) is UINT16, 'signed int' INT16, 'long' INT32, 'unsigned long' UINT32. The user guide says 32-bit values are big-endian with the high register at the lower address (worked example on fault register 476/477), so ABCD.
- Addresses here are for a controller that is the master (rotary switch 0). For a slave controller read through the master, add switch position x 500 to addresses below 8000 (the list has ready-made Slave01-Slave15 sheets).
- Heating circuits 02-08 follow the same layout as circuit 01 at a 13-register stride (input flow temperature 115, 128, ... 193; holding blocks 83, 96, ... 161). Boilers 2-16 repeat the boiler 1 block at +40 (8040, 8080, ...). Only circuit 00, circuit 01 and boiler 1 are listed here.
- Left out: DHW 2, alternative heat generator, heat pump, CHP, solar, fresh-water station, FM-SI, cascade buffer-charging settings, fault extra-info registers 484-499 and the 'reserved for legacy purposes' block. The cascade counters 360-362 are left out because the list gives no meaning for their values (count or bit mask).
- Fault registers hold message keys that are decoded with the Buderus message-key list (also in the ZIP); a value stays until the message clears.
- Coils and discrete inputs are not used by the controller (function codes 01, 02, 05 and 15 are listed as supported, but the guide says they are not used).
- Not listed: fault registers 5-10 at input 266-277 (unsigned long pairs, same format as 476-483), added to the list for firmware after 1.8; up to 1.8 only registers 1-4 exist and the newest message is always in register 1.
Check it against the live device. A register map tells you what the controller can expose; the unit in front of you may differ by firmware or options. Read a few registers and compare them with the unit’s own display; for a 32-bit value the float and byte-order decoder shows all four word orders at once, so a wrong word order or scale is obvious. New to this? Read what a register map is and why addresses are off by one.
Questions about the Buderus Logamatic 5000 boiler and system controller (Modbus TCP, datapoint list 4.0)
What Modbus registers does the Buderus Logamatic 5000 boiler and system controller (Modbus TCP, datapoint list 4.0) have?
This map lists 109 registers: 82 input registers, 27 holding registers. 26 of them can be written. Registers vary with firmware, options and configuration, so confirm against the device.
Are the Buderus Logamatic 5000 boiler and system controller (Modbus TCP, datapoint list 4.0) Modbus addresses 0-based or 1-based?
The manufacturer's document numbers registers 0-based (the number printed is the address on the wire). Every address on this page is the 0-based wire address you put in the request; the documented number is shown under it where it differs. The datapoint list gives decimal addresses that go straight into the request. Buderus' own conversion is Modicon = 40000 (holding) or 30000 (input) + address + 1, so holding register 400 is 40401 in Modicon notation.
What byte order does the Buderus Logamatic 5000 boiler and system controller (Modbus TCP, datapoint list 4.0) use for 32-bit values?
Multi-register values in this map use ABCD (high word first (big-endian)). Set your client to this order for every 32/64-bit value in the table.
What are the minimum Modbus registers to integrate the Buderus Logamatic 5000 boiler and system controller (Modbus TCP, datapoint list 4.0)?
Start with HR 402 Heat generator operating mode (Heat generator operating mode (on/off)); HR 400 System flow temperature setpoint (System flow temperature setpoint); HR 405 Strategy bit block (Strategy bit block (temperature- or output-led)); HR 0 Heartbeat (in) (Heartbeat counter); IR 0 Outdoor temperature (Outdoor temperature); IR 4 System flow temperature (System flow temperature); IR 5 System HMI status (System HMI status); IR 8001 Boiler 1 flow temperature (Boiler 1 flow temperature); IR 8013 Boiler 1 status bits (Boiler 1 status bits (burner on, faults)); IR 476 Fault register 1 (Fault register 1 (message key)).
How do I enable Modbus control of the Buderus Logamatic 5000 boiler and system controller (Modbus TCP, datapoint list 4.0)?
Service menu > Connectivity: Local Area Network = Modbus TCP/IP (factory: Internet); Modbus communication = with or without heartbeat ('No' disables Modbus); Allow write access = On; Provide extended monitor data = On (factory Off, required for Modbus data). Then Service menu > Heat generation > Strategy data > Basic settings: enable 'Heat demand via Modbus' (and disable 'Internal heat demand' for exclusive BMS control).
What happens when the Buderus Logamatic 5000 boiler and system controller (Modbus TCP, datapoint list 4.0) loses Modbus communication?
With 'Modbus communication = with heartbeat', the BMS must keep writing a changing counter to holding 0; holding 1 echoes it. If no new value arrives within the timeout (120-600 s, default 180 s) the controller raises a 'connection to building management faulty' message. 'Without heartbeat' disables loss detection.
Where is the official Buderus Logamatic 5000 boiler and system controller (Modbus TCP, datapoint list 4.0) Modbus documentation?
The source is Modbus TCP/IP Datenpunktliste von Logamatic 5000/Control 8000 Series (CustomerModbus_4.0_de.xlsx) and Hinweise zur Ansteuerung der Regelgeräteserie Logamatic 5000 über Modbus TCP/IP (Datenpunktliste product version 4.0; Anwenderdokumentation dated 2024-01-12), revision 2026-01-20, published free by Buderus at https://www.buderus.de/resource/blob/106518/0a9c1e567034bd412e389b11cbf923cb/Modbus%20Logamatic%205000%20Version%204.0.x.zip.
More Buderus Modbus register maps
Source: Modbus TCP/IP Datenpunktliste von Logamatic 5000/Control 8000 Series (CustomerModbus_4.0_de.xlsx) and Hinweise zur Ansteuerung der Regelgeräteserie Logamatic 5000 über Modbus TCP/IP · Datenpunktliste product version 4.0; Anwenderdokumentation dated 2024-01-12 · rev. 2026-01-20. Register numbers, types, scaling and units are reproduced as published; descriptions are our own.