Easy BACnetDual-heat-exchanger condensing boiler controller · BACnet points list
Lochinvar SYNC BACnet points list
Updated 28 October 2026
The SYNC boiler has two heat exchangers in one cabinet, so its BACnet MS/TP map repeats the flame, switch, temperature and status points for unit 1 and unit 2. Access is through Lochinvar's Modbus/BACnet communication board.
This page lists 62 BACnet objects for the Lochinvar SYNC — 9 of them writable — with each object’s type, instance number, name, engineering units and access. It is re-typed from Lochinvar’s own free documentation, linked below.
- Manufacturer
- Lochinvar
- Model
- SYNC
- Equipment
- Dual-heat-exchanger condensing boiler controller
- Equipment type
- Boilers & water heaters
- BACnet objects
- 62 (9 writable)
- Transport
- BACnet MS/TP
- Firmware
- Not stated
- Default device instance
- 630000 + MAC address (base is model dependent and can be changed)
- Also known as
- SYNC 1.0, SYNC 1.3, SYNC 1.5, SYNC-MODB
Reference only, provided as-is: verify against Lochinvar’s current documentation and the live device before use. Not official Lochinvar information. Terms of use.
BMS integration notes: Lochinvar SYNC
Pick the BMS control mode at the boiler, then write AV 0 Configuration so the unit knows which values the BAS will supply. After that the BAS sends an enable, a rate command (AV 2), or both, and keeps rewriting them. Status, temperatures and the status, blocking and lockout codes can be read without taking control.
Minimum points to map
The short list most integrators start with — enough to run the unit from a BMS. Map more as the job needs.
| Object | Name | Why | Access |
|---|---|---|---|
| AV 0 | Configuration | Bitmask of BAS-supplied inputs; resend before commands | Write |
| BV 0 | Boiler Enable | Enable / call for heat from the BAS | Write |
| AV 2 | 0-10 Volt Input / Rate Command / Setpoint Command | Rate command: firing % or setpoint, per BMS Type | Write |
| AI 13 | Unit 1 Status Code | What heat exchanger 1 is doing; 40 = lockout | Read |
| AI 22 | Unit 2 Status Code | What heat exchanger 2 is doing; 40 = lockout | Read |
| AI 8 | Outlet Temperature 1 | Outlet temperature, heat exchanger 1 | Read |
| AI 17 | Outlet Temperature 2 | Outlet temperature, heat exchanger 2 | Read |
| AI 15 | Unit 1 Lockout Code | Lockout cause, heat exchanger 1; valid only at status 40 | Read |
| AI 24 | Unit 2 Lockout Code | Lockout cause, heat exchanger 2; valid only at status 40 | Read |
Enable & remote start
Set Demand Configuration 4, 5 or 6 under Main > Setup > Service/Setup > Demand Config. 4: local setpoints plus BV 0 enable. 5: enable plus AV 2 rate command. 6: AV 2 modulation % alone. Set the matching AV 0 bits first. AV 2 means firing % or temperature setpoint depending on the BMS Type setting (Power or Setpoint); as a setpoint it is scaled like a 0-10 V signal between the BMS temperatures at low and high input.
Heartbeat & communication loss
If BAS-written temperatures or commands stop arriving, the unit reverts to its own readings and controls. The timeout is set under Main > Setup > BMS > Modbus / BACnet Timeout; the manual gives 5-120 s with a 10 s default in one place and 0-120 s in another. Every write resets it, and Lochinvar recommends the shortest value. Commands without temperatures must be refreshed at least every 4 minutes.
Sensors & values from the BMS
Set the AV 0 bits for the values the BAS will supply, then write them to the analog values: AV 3 tank setpoint, AV 4 tank temperature, AV 5 outdoor temperature, AV 6 system supply temperature. Values are in °C. Temperatures must be rewritten every few seconds or the unit returns to its own sensors.
Network setup
- MAC address from dip switches 1-8 (master only, so 0-127); baud from switches 9-10: 9600, 19200, 38400 or 76800.
- Device instance = base 630000 + MAC address; the base can be changed.
Watch out for
- The manual says to resend the AV 0 configuration bits before each command.
- In a cascade only the Leader needs the BACnet board for control; it then reports cascade totals only, so fit a board to every unit to see each one.
- Without BMS mode active the board is monitor-only: the read-only points can be polled while the unit runs on its own controls.
- Status, temperature and code points come in pairs for heat exchanger 1 and 2.
Lochinvar SYNC BACnet objects
Type: AI, AO, AV, BI, BO, BV, MI/MO/MV (multi-state) · Access: Read read-only, Write writable, Command writable with a priority array.
| Description | States | |||||
|---|---|---|---|---|---|---|
| BVmin | 0 | Boiler Enable | BAS enable command for the appliance | Write | ||
| BV | 4 | Tank Thermostat | Tank / DHW thermostat call | Write | ||
| BI | 0 | Manual Reset High Limit 1 | Safety / proving switch status | Read | ||
| BI | 1 | Flow Switch 1 | Safety / proving switch status | Read | ||
| BI | 2 | Gas Pressure Switch 1 | Safety / proving switch status | Read | ||
| BI | 3 | Louver Proving Switch 1 | Safety / proving switch status | Read | ||
| BI | 4 | Flap Valve 1 | Safety / proving switch status | Read | ||
| BI | 5 | Blocked Drain Switch 1 | Safety / proving switch status | Read | ||
| BI | 6 | Auto Reset High Limit 1 | Safety / proving switch status | Read | ||
| BI | 7 | Flame 1 | Flame status | Read | ||
| BI | 8 | Enable | Enable input status | Read | ||
| BI | 9 | Tank Thermostat | Tank / DHW thermostat call | Read | ||
| BI | 16 | Manual Reset High Limit 2 | Safety / proving switch status | Read | ||
| BI | 17 | Flow Switch 2 | Safety / proving switch status | Read | ||
| BI | 18 | Gas Pressure Switch 2 | Safety / proving switch status | Read | ||
| BI | 19 | Louver Proving Switch 2 | Safety / proving switch status | Read | ||
| BI | 20 | Flap Valve 2 | Safety / proving switch status | Read | ||
| BI | 21 | Blocked Drain Switch 2 | Safety / proving switch status | Read | ||
| BI | 22 | Flame 2 | Flame status | Read | ||
| BI | 32 | Run-time Contacts 1 | Output or relay status | Read | ||
| BI | 33 | Alarm Contacts 1 | Output or relay status | Read | ||
| BI | 34 | Boiler Pump 1 | Output or relay status | Read | ||
| BI | 35 | DHW Pump 1 | Output or relay status | Read | ||
| BI | 37 | Gas Valve 1 | Output or relay status | Read | ||
| BI | 38 | System Pump | Output or relay status | Read | ||
| BI | 40 | Run-time Contacts 2 | Output or relay status | Read | ||
| BI | 41 | Alarm Contacts 2 | Output or relay status | Read | ||
| BI | 42 | Boiler Pump 2 | Output or relay status | Read | ||
| BI | 43 | DHW Pump 2 | Output or relay status | Read | ||
| BI | 45 | Gas Valve 2 | Output or relay status | Read | ||
| BI | 48 | Fan 1 Power | Output or relay status | Read | ||
| BI | 49 | Fan 2 Power | Output or relay status | Read | ||
| AI | 0 | Binary Inputs 0 - 15 | Packed word of binary inputs 0-15 | Read | ||
| AI | 1 | Binary Inputs 16 - 31 | Packed word of binary inputs 16-31 | Read | ||
| AI | 2 | Binary Inputs 32 - 47 | Packed word of binary inputs 32-47 | Read | ||
| AI | 3 | System / Cascade Setpoint | Setpoint value | °C | Read | |
| AI | 5 | Cascade Total Power | Total cascade firing capacity | % | Read | |
| AI | 6 | Cascade Current Power | Current cascade firing rate | % | Read | |
| AI | 7 | Outlet Setpoint 1 | Setpoint value | °C | Read | |
| AImin | 8 | Outlet Temperature 1 | Temperature reading | °C | Read | |
| AI | 9 | Inlet Temperature 1 | Temperature reading | °C | Read | |
| AI | 10 | Flue Temperature 1 | Temperature reading | °C | Read | |
| AI | 11 | Firing Rate 1 | Burner firing rate | % | Read | |
| AImin | 13 | Unit 1 Status Code | Current operating status code | Read | ||
| AI | 14 | Unit 1 Blocking Code | Active blocking (soft lockout) code | Read | ||
| AImin | 15 | Unit 1 Lockout Code | Active lockout code | Read | ||
| AI | 16 | Outlet Setpoint 2 | Setpoint value | °C | Read | |
| AImin | 17 | Outlet Temperature 2 | Temperature reading | °C | Read | |
| AI | 18 | Inlet Temperature 2 | Temperature reading | °C | Read | |
| AI | 19 | Flue Temperature 2 | Temperature reading | °C | Read | |
| AI | 20 | Firing Rate 2 | Burner firing rate | % | Read | |
| AImin | 22 | Unit 2 Status Code | Current operating status code | Read | ||
| AI | 23 | Unit 2 Blocking Code | Active blocking (soft lockout) code | Read | ||
| AImin | 24 | Unit 2 Lockout Code | Active lockout code | Read | ||
| AI | 25 | Binary Inputs 48 - 63 | Packed word of binary inputs 48-63 | Read | ||
| AVmin | 0 | Configuration | Bitmask selecting which values the BAS supplies | Write | ||
| AV | 1 | Binary Values | Packed word of the binary value commands | Write | ||
| AVmin | 2 | 0-10 Volt Input / Rate Command / Setpoint Command | BAS rate or setpoint command (0-100%) | % | Write | |
| AV | 3 | Tank Setpoint | Setpoint value | °C | Write | |
| AV | 4 | Tank Temperature | Temperature reading | °C | Write | |
| AV | 5 | Outdoor Temperature | Temperature reading | °C | Write | |
| AV | 6 | System Supply Temperature | Temperature reading | °C | Write |
No points match these filters.
Object ID lookup: Lochinvar SYNC point IDs by name
BV0Boiler EnableBV4Tank ThermostatBI0Manual Reset High Limit 1BI1Flow Switch 1BI2Gas Pressure Switch 1BI3Louver Proving Switch 1BI4Flap Valve 1BI5Blocked Drain Switch 1BI6Auto Reset High Limit 1BI7Flame 1BI8EnableBI9Tank ThermostatBI16Manual Reset High Limit 2BI17Flow Switch 2BI18Gas Pressure Switch 2BI19Louver Proving Switch 2BI20Flap Valve 2BI21Blocked Drain Switch 2BI22Flame 2BI32Run-time Contacts 1BI33Alarm Contacts 1BI34Boiler Pump 1BI35DHW Pump 1BI37Gas Valve 1BI38System PumpBI40Run-time Contacts 2BI41Alarm Contacts 2BI42Boiler Pump 2BI43DHW Pump 2BI45Gas Valve 2BI48Fan 1 PowerBI49Fan 2 PowerAI0Binary Inputs 0 - 15AI1Binary Inputs 16 - 31AI2Binary Inputs 32 - 47AI3System / Cascade SetpointAI5Cascade Total PowerAI6Cascade Current PowerAI7Outlet Setpoint 1AI8Outlet Temperature 1AI9Inlet Temperature 1AI10Flue Temperature 1AI11Firing Rate 1AI13Unit 1 Status CodeAI14Unit 1 Blocking CodeAI15Unit 1 Lockout CodeAI16Outlet Setpoint 2AI17Outlet Temperature 2AI18Inlet Temperature 2AI19Flue Temperature 2AI20Firing Rate 2AI22Unit 2 Status CodeAI23Unit 2 Blocking CodeAI24Unit 2 Lockout CodeAI25Binary Inputs 48 - 63AV0ConfigurationAV1Binary ValuesAV20-10 Volt Input / Rate Command / Setpoint CommandAV3Tank SetpointAV4Tank TemperatureAV5Outdoor TemperatureAV6System Supply Temperature
Integration notes
- BACnet needs the optional Lochinvar Modbus/BACnet communication board; address and baud rate are set on its dip switches.
- The BACnet board is an MS/TP master only, so MAC addresses 0-127 are usable.
- AV 0 (Configuration) is a bitmask: set a bit to 1 to make the appliance use the BAS-written value instead of its own input.
- BAS-supplied temperatures must be rewritten every few seconds and other commands at least every 4 minutes, or the unit reverts to local control.
- Temperatures are in °C on the bus.
Check it against the live device. A points list tells you what the controller can expose; the unit in front of you may differ by firmware or installed options. This list is provided as-is for reference only and may contain mistakes — confirming it before you write, map or commission anything is up to you (terms). Easy BACnet scans a network for BACnet IP devices from an Android phone, reads every object on the SYNC and exports what it actually has to Excel — free. New to BACnet? Start with what a BACnet points list is and what the object types mean.
Questions about the Lochinvar SYNC
How many BACnet points does the Lochinvar SYNC have?
This list has 62 BACnet objects: 23 analog inputs, 7 analog values, 30 binary inputs, 2 binary values. The exact set on a given unit depends on its firmware, installed options and configuration.
Which Lochinvar SYNC BACnet points are writable?
9 of the 62 objects accept a write. Points marked Command have a priority array: a write holds until it is released, so release it back to automatic when you are done.
Where is the official Lochinvar SYNC BACnet documentation?
The source is Modbus and BACnet Communication Instructions (SYNC 1.0 - 1.3 - 1.5) (SYNC-MODB_100161723_2000017706), revision Rev L, 05/17, published free by Lochinvar at https://assets.lochinvar.com/damroot/Original/10014/594260SYNC-MODB_100161723_2000017706__REV%20L_BACNET.pdf.
What are the minimum BACnet points to integrate the Lochinvar SYNC?
Start with AV 0 Configuration (Bitmask of BAS-supplied inputs; resend before commands); BV 0 Boiler Enable (Enable / call for heat from the BAS); AV 2 0-10 Volt Input / Rate Command / Setpoint Command (Rate command: firing % or setpoint, per BMS Type); AI 13 Unit 1 Status Code (What heat exchanger 1 is doing; 40 = lockout); AI 22 Unit 2 Status Code (What heat exchanger 2 is doing; 40 = lockout); AI 8 Outlet Temperature 1 (Outlet temperature, heat exchanger 1); AI 17 Outlet Temperature 2 (Outlet temperature, heat exchanger 2); AI 15 Unit 1 Lockout Code (Lockout cause, heat exchanger 1; valid only at status 40); AI 24 Unit 2 Lockout Code (Lockout cause, heat exchanger 2; valid only at status 40).
How do I enable BMS control of the Lochinvar SYNC?
Set Demand Configuration 4, 5 or 6 under Main > Setup > Service/Setup > Demand Config. 4: local setpoints plus BV 0 enable. 5: enable plus AV 2 rate command. 6: AV 2 modulation % alone. Set the matching AV 0 bits first. AV 2 means firing % or temperature setpoint depending on the BMS Type setting (Power or Setpoint); as a setpoint it is scaled like a 0-10 V signal between the BMS temperatures at low and high input.
Does the Lochinvar SYNC need a BACnet heartbeat or have a communication timeout?
If BAS-written temperatures or commands stop arriving, the unit reverts to its own readings and controls. The timeout is set under Main > Setup > BMS > Modbus / BACnet Timeout; the manual gives 5-120 s with a 10 s default in one place and 0-120 s in another. Every write resets it, and Lochinvar recommends the shortest value. Commands without temperatures must be refreshed at least every 4 minutes.
Can the BMS supply sensor values to the Lochinvar SYNC?
Set the AV 0 bits for the values the BAS will supply, then write them to the analog values: AV 3 tank setpoint, AV 4 tank temperature, AV 5 outdoor temperature, AV 6 system supply temperature. Values are in °C. Temperatures must be rewritten every few seconds or the unit returns to its own sensors.
How do I check these points on the real SYNC?
Scan the network with a BACnet IP browser such as Easy BACnet, open the device and compare its object list with this table. Anything missing is usually an option that isn't installed or a point that is disabled in the controller's configuration.
More Lochinvar BACnet points lists
- Commercial condensing water heater controller
Lochinvar Armor 1250-4000 water heater (SMART SYSTEM)
Lochinvar Armor volume water heaters, models 1250-4000, Series 100 and 101, with the SMART SYSTEM control and the Modbus/BACnet communication board.
Also known as: Armor, Armor 1250, Armor 4000, AWH, Armor Series 100, Armor Series 101, SMART SYSTEM, MTR-01, 100305786 - Commercial boiler / water heater / pool heater controller
Lochinvar Copper-fin II / IIE (CFX, CHX, CPX)
Lochinvar Copper-fin II/IIE boilers and water heaters (models 402-2072) and pool heaters (502-2072) with the SMART SYSTEM control.
Also known as: Copper-fin, Copper-Fin II, Copper-fin IIE, CFX, CHX, CPX, C(F,H,P)X-MODB, CB 402-2072, CW 402-2072 - Condensing boiler controller
Lochinvar Crest
Crest FB/OF 751-6001 and FCB 1000-6000 condensing boilers (the manual uses the same map for Hellcat).
Also known as: Crest FB, Crest OF, Crest FCB, Hellcat - Heating appliance controller gateway (IPW)
Lochinvar IPW (ProtoNode FPC-N54)
Lochinvar IPW units, read through the ProtoNode FPC-N54 gateway (Appendix C.8).
Also known as: IPW, Lochinvar IPW, ProtoNode FPC-N54 - Condensing boiler / water heater controller
Lochinvar Knight / Armor (SMART TOUCH)
Knight, Knight XL, Armor, Wall Mount, Wall Hung, AQUAS, FTXL and Shield boilers and water heaters with the SMART TOUCH control.
Also known as: Knight XL, Outdoor Knight, Armor, Wall Mount, Wall Hung, AQUAS, FTXL, Shield, MODB-I-O - Commercial boiler controller gateway
Lochinvar Knight FTXL (ProtoNode FPC-N54)
Lochinvar Knight FTXL fire-tube boilers, read through the ProtoNode FPC-N54 gateway.
Also known as: Knight FTXL, FTXL, Lochinvar FTXL, ProtoNode FPC-N54 - Electric boiler controller
Lochinvar Lectrus electric boiler (KEB)
Lochinvar Lectrus electric boilers, models KEB 0015-0150, with the Modbus/BACnet communication board.
Also known as: Lectrus, KEB, KEB0015, KEB0150, MODB-I-O-KEB, Lochinvar electric boiler - Commercial boiler controller gateway
Lochinvar Power Fin 2.5-5.0 (ProtoNode FPC-N54)
Lochinvar Power Fin boilers in the 2.5-5.0 size range (the guide's "Powerfin_2.5_5.0" profile), read through the ProtoNode FPC-N54 gateway.
Also known as: Power Fin 2.5-5.0, Power-Fin 2500-5000, PBN/PFN 2.5-5.0, Lochinvar Power Fin, ProtoNode FPC-N54 - Commercial boiler / water heater controller
Lochinvar Power-Fin (SMART SYSTEM)
Lochinvar Power-fin models 502-1302 and 1501-2001, with the SMART SYSTEM control and the Modbus/BACnet communication board.
Also known as: Power-fin, Powerfin, PBX-PFX-MODB, SMART SYSTEM - Commercial water heater controller
Lochinvar Regent
Regent IWH 500-1000 commercial gas water heaters.
Also known as: Regent IWH, IWH500-1000 - Heat pump water heater plant controller
Lochinvar Veritus / Emerge_X heat pump water heater (ProtoNode FPC-N54)
Lochinvar Veritus and Emerge_X heat pump water heater systems (up to 64 units), read through the ProtoNode FPC-N54.
Also known as: Veritus, Emerge_X, Emerge X, Lochinvar Veritus, ProtoNode FPC-N54
Source: Modbus and BACnet Communication Instructions (SYNC 1.0 - 1.3 - 1.5) · SYNC-MODB_100161723_2000017706 · rev. Rev L, 05/17. Object names, instances and units are reproduced as published; descriptions are our own.