Easy BACnetCondensing boiler controller · BACnet points list
Lochinvar Crest BACnet points list
Updated 28 October 2026
The Crest boiler exposes BACnet MS/TP through Lochinvar's Modbus/BACnet communication board. Besides the usual enable, temperature, firing rate and status/blocking/lockout codes, larger and FCB models add dual-burner, damper, O2 trim and cascade member lockout points.
This page lists 77 BACnet objects for the Lochinvar Crest — 10 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
- Crest
- Equipment
- Condensing boiler controller
- Equipment type
- Boilers & water heaters
- BACnet objects
- 77 (10 writable)
- Transport
- BACnet MS/TP
- Firmware
- Not stated
- Default device instance
- Base + MAC address: 610000 for FB 751-2001, 670000 for FB 2501-6001, 680000 for FCB1000-6000 (base can be changed)
- Also known as
- Crest FB, Crest OF, Crest FCB, Hellcat
BMS integration notes: Lochinvar Crest
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 | Boiler Status Code | What the boiler is doing; 40 = lockout | Read |
| AI 8 | Outlet Temperature | Boiler outlet water temperature, °C | Read |
| AI 11 | Firing Rate | Burner firing rate, % | Read |
| AI 15 | Boiler Lockout Code | Lockout cause; valid only when status code is 40 | Read |
Enable & remote start
Set the Demand Configuration under Main Menu > Setup > BMS. ENABLE active / BMS inactive: local setpoints plus BV 0 enable. ENABLE and BMS active: BV 0 enable plus AV 2 rate or setpoint command. ENABLE inactive / BMS active: AV 2 modulation % or setpoint alone. Always 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 stop arriving within the timeout, the unit reverts to its own sensor inputs. On Crest the timeout is programmable from 5 to 120 s (Main Menu > Setup > BAS); Lochinvar recommends the shortest value. On Hellcat and Regent it is fixed at 300 s. Other commands must be refreshed at least every 4 minutes or the boiler runs on its own inputs.
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, AV 7 system return 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 + MAC address; bases are 610000 (FB 751-2001), 670000 (FB 2501-6001) and 680000 (FCB1000-6000). The base can be changed (0-4194048).
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.
- Several BI/AI points exist only on certain Crest sizes or on FCB models; check the size notes in each description.
Lochinvar Crest 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 | Safety / proving switch status | Read | ||
| BI | 1 | Flow Switch | Safety / proving switch status | Read | ||
| BI | 2 | Gas Pressure Switch | Safety / proving switch status | Read | ||
| BI | 3 | Louver Proving Switch | Safety / proving switch status | Read | ||
| BI | 4 | Proof of Closure | Gas valve proof of closure (FCB1000-6001 only; usable on FB/OF4001-6001) | Read | ||
| BI | 5 | Blocked Drain Switch | Safety / proving switch status | Read | ||
| BI | 7 | Flame 1 | Flame status | Read | ||
| BI | 8 | Enable | Enable input status (Crest 751-6001 only) | Read | ||
| BI | 9 | Tank Thermostat | Tank / DHW thermostat call (Crest 751-6001 only) | Read | ||
| BI | 10 | Blocked Vent Switch | Safety / proving switch status | Read | ||
| BI | 12 | Fan 2 Proving Switch | Second fan proving switch (751-6001 only; older dual-fan models) | Read | ||
| BI | 17 | Internal LWCO | Safety / proving switch status (Crest FCB1000-6001 only) | Read | ||
| BI | 18 | Gas Pressure Switch 2 | Safety / proving switch status (Crest FCB1000-6001 only) | Read | ||
| BI | 20 | Flue Damper Switch | Safety / proving switch status | Read | ||
| BI | 22 | Flame 2 | Flame status | Read | ||
| BI | 25 | Enable | Enable input status (Crest FCB1000-6001 only) | Read | ||
| BI | 29 | Tank Thermostat | Tank / DHW thermostat call (Crest FCB1000-6001 only) | Read | ||
| BI | 32 | Run Time Contacts | Output or relay status | Read | ||
| BI | 33 | Alarm Contacts | Output or relay status | Read | ||
| BI | 34 | Boiler Pump | Output or relay status | Read | ||
| BI | 35 | DHW Pump | Output or relay status | Read | ||
| BI | 36 | Louver Relay | 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 | DHW Recirc Pump | Output or relay status (Crest FCB1000-6001 only) | Read | ||
| BI | 43 | Flue Damper Output | Output or relay status | Read | ||
| BI | 45 | Gas Valve 2 | Output or relay status | Read | ||
| BI | 46 | Transition Gas Valve | Output or relay status (Crest 751-1501 only) | Read | ||
| BI | 48 | Main Fan 1 | Output or relay status | Read | ||
| BI | 49 | Main Fan 2 | Output or relay status (Crest 2501-6001 only; Dual fan models only) | Read | ||
| BI | 50 | External Spark / HSI | Output or relay status | Read | ||
| BI | 51 | Air Valve Trigger | Output or relay status | Read | ||
| BI | 52 | Air Valve Proving | Safety / proving switch 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 | 4 | System Pump Speed | Pump speed output | % | 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 | Setpoint value | °C | Read | |
| AImin | 8 | Outlet Temperature | Temperature reading | °C | Read | |
| AI | 9 | Inlet Temperature | Temperature reading | °C | Read | |
| AI | 10 | Flue Temperature | Temperature reading | °C | Read | |
| AImin | 11 | Firing Rate | Burner firing rate | % | Read | |
| AI | 12 | Boiler Pump Speed | Pump speed output | % | Read | |
| AImin | 13 | Boiler Status Code | Current operating status code | Read | ||
| AI | 14 | Boiler Blocking Code | Active blocking (soft lockout) code | Read | ||
| AImin | 15 | Boiler Lockout Code | Active lockout code | Read | ||
| AI | 18 | Air Damper Target Angle | Combustion / flow value (Crest FCB1000-6001 only) | Read | ||
| AI | 19 | Gas Damper Target Angle | Combustion / flow value (Crest FCB1000-6001 only) | Read | ||
| AI | 20 | Fan Speed Target | Combustion / flow value (Crest FCB1000-6001 only) | Read | ||
| AI | 22 | O2 Sensor Status | Combustion / flow value (Crest FCB1000-6001 only) | Read | ||
| AI | 23 | Current Trim Factor | Combustion / flow value (Crest FCB1000-6001 only) | Read | ||
| AI | 24 | Barometer | Combustion / flow value (Crest FCB1000-6001 only) | Read | ||
| AI | 25 | Binary Inputs 48-63 | Packed word of binary inputs 48-63 | Read | ||
| AI | 26 | Lock-Out Error Leader | Lockout flag for this cascade unit | Read | ||
| AI | 27 | Lock-Out Error Member 1 | Lockout flag for this cascade unit | Read | ||
| AI | 28 | Lock-Out Error Member 2 | Lockout flag for this cascade unit | Read | ||
| AI | 29 | Lock-Out Error Member 3 | Lockout flag for this cascade unit | Read | ||
| AI | 30 | Lock-Out Error Member 4 | Lockout flag for this cascade unit | Read | ||
| AI | 31 | Lock-Out Error Member 5 | Lockout flag for this cascade unit | Read | ||
| AI | 32 | Lock-Out Error Member 6 | Lockout flag for this cascade unit | Read | ||
| AI | 33 | Lock-Out Error Member 7 | Lockout flag for this cascade unit | Read | ||
| AI | 35 | Flame 1 | Flame status (Crest FCB1000-6001 only) | Read | ||
| AI | 36 | Flame 2 | Flame status (Crest FCB1000-6001 only) | Read | ||
| AI | 37 | Corrected O2 Reading | Combustion / flow value (Crest FCB1000-6001 only) | Read | ||
| AVmin | 0 | Configuration | Bitmask selecting which values the BAS supplies | Write | ||
| AV | 1 | Coils | 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 | |
| AV | 7 | System Return Temperature | Temperature reading | °C | Write |
No points match these filters.
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.
- Several points only exist on certain Crest sizes; the size range is given in the point description.
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. Easy BACnet scans a network for BACnet IP devices from an Android phone, reads every object on the Crest 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 Crest
How many BACnet points does the Lochinvar Crest have?
This list has 77 BACnet objects: 34 analog inputs, 8 analog values, 33 binary inputs, 2 binary values. The exact set on a given unit depends on its firmware, installed options and configuration.
Which Lochinvar Crest BACnet points are writable?
10 of the 77 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 Crest BACnet documentation?
The source is Modbus and BACnet Communication Instructions (Crest FB/OF751-6001, FCB1000-6000 & Regent IWH500-1000) (100161012_2000020084), revision Rev X, 04/26, published free by Lochinvar at https://assets.lochinvar.com/damroot/Original/10017/MODB_100161012_2000020084_REV%20X_(71343).pdf.
What are the minimum BACnet points to integrate the Lochinvar Crest?
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 Boiler Status Code (What the boiler is doing; 40 = lockout); AI 8 Outlet Temperature (Boiler outlet water temperature, °C); AI 11 Firing Rate (Burner firing rate, %); AI 15 Boiler Lockout Code (Lockout cause; valid only when status code is 40).
How do I enable BMS control of the Lochinvar Crest?
Set the Demand Configuration under Main Menu > Setup > BMS. ENABLE active / BMS inactive: local setpoints plus BV 0 enable. ENABLE and BMS active: BV 0 enable plus AV 2 rate or setpoint command. ENABLE inactive / BMS active: AV 2 modulation % or setpoint alone. Always 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 Crest need a BACnet heartbeat or have a communication timeout?
If BAS-written temperatures stop arriving within the timeout, the unit reverts to its own sensor inputs. On Crest the timeout is programmable from 5 to 120 s (Main Menu > Setup > BAS); Lochinvar recommends the shortest value. On Hellcat and Regent it is fixed at 300 s. Other commands must be refreshed at least every 4 minutes or the boiler runs on its own inputs.
Can the BMS supply sensor values to the Lochinvar Crest?
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, AV 7 system return 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 Crest?
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 - 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 water heater controller
Lochinvar Regent
Regent IWH 500-1000 commercial gas water heaters.
Also known as: Regent IWH, IWH500-1000 - Dual-heat-exchanger condensing boiler controller
Lochinvar SYNC
SYNC 1.0, 1.3 and 1.5 condensing boilers (two heat exchangers, reported as unit 1 and unit 2).
Also known as: SYNC 1.0, SYNC 1.3, SYNC 1.5, SYNC-MODB
Source: Modbus and BACnet Communication Instructions (Crest FB/OF751-6001, FCB1000-6000 & Regent IWH500-1000) · 100161012_2000020084 · rev. Rev X, 04/26. Object names, instances and units are reproduced as published; descriptions are our own.