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Commercial condensing water heater controller · BACnet points list
Lochinvar Armor 1250-4000 water heater (SMART SYSTEM) BACnet points list
Updated 28 October 2026
The large Armor water heaters (1250-4000 MBH) talk BACnet MS/TP through Lochinvar's add-on Modbus/BACnet communication board. The fixed object map has two writable binary values (enable and tank thermostat), safety-switch and output status inputs, temperatures, firing rate, status/blocking/lockout codes, cascade totals, and analog values the BAS writes for configuration, rate or setpoint, tank setpoint and tank temperature.
This page lists 44 BACnet objects for the Lochinvar Armor 1250-4000 water heater (SMART SYSTEM) — 7 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
- Armor 1250-4000 water heater (SMART SYSTEM)
- Equipment
- Commercial condensing water heater controller
- Equipment type
- Boilers & water heaters
- BACnet objects
- 44 (7 writable)
- Transport
- BACnet MS/TP
- Firmware
- Not stated
- Default device instance
- 640000 + MAC address
- Also known as
- Armor, Armor 1250, Armor 4000, AWH, Armor Series 100, Armor Series 101, SMART SYSTEM, MTR-01, 100305786
BMS integration notes: Lochinvar Armor 1250-4000 water heater (SMART SYSTEM)
Set parameter H5 ModBus to Active on the SMART SYSTEM control, then write AV 0 Configuration so the heater knows which values the BAS will supply. After that the BAS sends an enable (BV 0 / AV 1), a rate or setpoint 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 |
| AV 1 | Coils | Enable command: 1 = enable, 0 = disable | Write |
| AV 2 | 0-10 Volt Input / Rate Command / Setpoint Command | Rate command: firing % or setpoint, per BMS Type | Write |
| AI 13 | Status Code | What the heater is doing; 40 = lockout | Read |
| AI 8 | Outlet Temperature | Outlet water temperature, °C | Read |
| AI 11 | Firing Rate | Burner firing rate, % | Read |
| AI 15 | Lockout Code | Lockout cause; valid only when status code is 40 | Read |
Enable & remote start
Set H5 ModBus = Active. Enable only (local setpoints): AV 0 = 0x0001 and AV 1 Coils = 1 (0 disables). Enable plus rate: AV 0 = 0x0005, AV 1 = 1 and AV 2 = modulation % or setpoint. Rate only: AV 0 = 0x0004 and AV 2. AV 2 is a firing % or a setpoint depending on the BMS Type setting; as a setpoint it is scaled like a 0-10 V signal between the BMS temperatures set for the low and high analog input.
Heartbeat & communication loss
BAS-written tank temperature and the 0-10 V/rate value must be refreshed every few seconds; parameter H6 ModBus Time sets the timeout (the manual gives 5-120 s with a 10 s default in one place and 1-255 s in another). Other commands such as the enable have a fixed 4-minute timeout. When either timer runs out the heater goes back to its local inputs.
Sensors & values from the BMS
Set the AV 0 bits for the values the BAS will supply, then write AV 3 tank setpoint and/or AV 4 tank temperature (°C). The tank temperature must be rewritten every few seconds or the heater returns to its own sensor.
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 = 640000 + MAC address (e.g. MAC 50 = 640050).
- RS-485 bus up to 4000 ft, 24 AWG shielded twisted pair, 120 ohm termination at each end, up to 32 nodes.
Watch out for
- The manual says to resend the AV 0 configuration bits before each command.
- In a cascade only the leader needs the board for control; it then reports cascade totals only, so fit a board to every unit to see each one.
- Without H5 set to Active the board is monitor-only.
- The lockout code changes during normal operation; read it only when the status code is 40.
Lochinvar Armor 1250-4000 water heater (SMART SYSTEM) 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 | |||||
|---|---|---|---|---|---|---|
| BV | 0 | Enable | BAS enable command (also packed in AV 1) | Write | ||
| BV | 4 | Tank Thermostat | BAS tank thermostat call | Write | ||
| BI | 0 | Manual Reset High Limit | Manual reset high limit input | Read | ||
| BI | 1 | Flow Switch | Flow switch input | Read | ||
| BI | 2 | Gas Pressure Switch | Gas pressure switch input | Read | ||
| BI | 3 | Louver Proving Switch | Louver proving switch input | Read | ||
| BI | 5 | Blocked Drain Switch | Blocked drain switch input | Read | ||
| BI | 6 | Auto Reset High Limit | Auto reset high limit input | Read | ||
| BI | 7 | Flame | Flame detected | Read | ||
| BI | 8 | Enable | Enable input status | Read | ||
| BI | 9 | Tank Thermostat | Tank thermostat input status | Read | ||
| BI | 32 | Run Time Contacts | Run-time contacts closed | Read | ||
| BI | 33 | Alarm Contacts | Alarm contacts closed | Read | ||
| BI | 35 | DHW Pump | DHW pump output | Read | ||
| BI | 37 | Gas Valve | Gas valve output | Read | ||
| BI | 38 | Recirculation Pump | Recirculation pump output | Read | ||
| BI | 48 | Power Fan | Blower (fan) power output | Read | ||
| AI | 0 | Binary Inputs 0-15 | Packed copy of binary inputs 0-15 | Read | ||
| AI | 1 | Binary Inputs 16-31 | Packed copy of binary inputs 16-31 | Read | ||
| AI | 2 | Binary Inputs 32-47 | Packed copy of binary inputs 32-47 | Read | ||
| AI | 3 | System / Cascade Setpoint | Active system or cascade setpoint | °C | Read | |
| AI | 5 | Cascade Total Power | Total cascade capacity, 100-800 % | % | Read | |
| AI | 6 | Cascade Current Power | Cascade firing rate now, 0-800 % | % | Read | |
| AImin | 8 | Outlet Temperature | Outlet water temperature | °C | Read | |
| AI | 9 | Inlet Temperature | Inlet water temperature | °C | Read | |
| AI | 10 | Flue Temperature | Flue gas temperature | °C | Read | |
| AImin | 11 | Firing Rate | Burner firing rate | % | Read | |
| AImin | 13 | Status Code | Appliance status code; 40 = lockout | Read | ||
| AI | 14 | Blocking Code | Blocking reason code; 0 = none | Read | ||
| AImin | 15 | Lockout Code | Lockout cause; valid when status code is 40 | Read | ||
| AI | 25 | Binary Inputs 48-63 | Packed copy of binary inputs 48-63 | Read | ||
| AI | 26 | Lock-Out Error Leader | Cascade leader lockout flag (0-1) | Read | ||
| AI | 27 | Lock-Out Error Member 1 | Cascade member 1 lockout flag (0-1) | Read | ||
| AI | 28 | Lock-Out Error Member 2 | Cascade member 2 lockout flag (0-1) | Read | ||
| AI | 29 | Lock-Out Error Member 3 | Cascade member 3 lockout flag (0-1) | Read | ||
| AI | 30 | Lock-Out Error Member 4 | Cascade member 4 lockout flag (0-1) | Read | ||
| AI | 31 | Lock-Out Error Member 5 | Cascade member 5 lockout flag (0-1) | Read | ||
| AI | 32 | Lock-Out Error Member 6 | Cascade member 6 lockout flag (0-1) | Read | ||
| AI | 33 | Lock-Out Error Member 7 | Cascade member 7 lockout flag (0-1) | Read | ||
| AVmin | 0 | Configuration | Bitmask of values the BAS will supply | Write | Bit 0 Enable, bit 1 Tank Thermostat, bit 2 Rate/0-10 V/Setpoint Command, bit 3 Tank Setpoint, bit 6 Tank Temperature | |
| AVmin | 1 | Coils | Packed BAS commands (enable, tank thermostat) | Write | ||
| AVmin | 2 | 0-10 Volt Input / Rate Command / Setpoint Command | Rate (modulation %) or setpoint command, per BMS Type | % | Write | |
| AV | 3 | Tank Setpoint | Tank setpoint from the BAS, 0-87.5 °C | °C | Write | |
| AV | 4 | Tank Temperature | Tank temperature from the BAS | °C | Write |
No points match these filters.
Integration notes
- BACnet needs the optional communication board; its address and baud rate are set on dip switches.
- The board is an MS/TP master only, so MAC addresses 0-127 are usable.
- AV 0 (Configuration) is a bitmask: setting a bit tells the heater to use the BAS-written value instead of its own input.
- AI 0-2 and AI 25 pack the binary inputs into 16-bit words.
- Temperatures are in °C on the bus.
- Revision C of this manual changed the analog-value table; earlier revisions list different analog values.
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 Armor 1250-4000 water heater (SMART SYSTEM) 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 Armor 1250-4000 water heater (SMART SYSTEM)
How many BACnet points does the Lochinvar Armor 1250-4000 water heater (SMART SYSTEM) have?
This list has 44 BACnet objects: 22 analog inputs, 5 analog values, 15 binary inputs, 2 binary values. The exact set on a given unit depends on its firmware, installed options and configuration.
Which Lochinvar Armor 1250-4000 water heater (SMART SYSTEM) BACnet points are writable?
7 of the 44 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 Armor 1250-4000 water heater (SMART SYSTEM) BACnet documentation?
The source is Modbus and BACnet Communication Instructions, Armor Models 1250-4000, Series 100 & 101 (100305786_2000558371 Rev C), revision 2022-09, published free by Lochinvar at https://assets.lochinvar.com/damroot/Original/10014/100305786_2000558371_Rev%20C_AWH%20Modbus%20Bacnet%20Manual%20(52880).pdf.
What are the minimum BACnet points to integrate the Lochinvar Armor 1250-4000 water heater (SMART SYSTEM)?
Start with AV 0 Configuration (Bitmask of BAS-supplied inputs; resend before commands); AV 1 Coils (Enable command: 1 = enable, 0 = disable); AV 2 0-10 Volt Input / Rate Command / Setpoint Command (Rate command: firing % or setpoint, per BMS Type); AI 13 Status Code (What the heater is doing; 40 = lockout); AI 8 Outlet Temperature (Outlet water temperature, °C); AI 11 Firing Rate (Burner firing rate, %); AI 15 Lockout Code (Lockout cause; valid only when status code is 40).
How do I enable BMS control of the Lochinvar Armor 1250-4000 water heater (SMART SYSTEM)?
Set H5 ModBus = Active. Enable only (local setpoints): AV 0 = 0x0001 and AV 1 Coils = 1 (0 disables). Enable plus rate: AV 0 = 0x0005, AV 1 = 1 and AV 2 = modulation % or setpoint. Rate only: AV 0 = 0x0004 and AV 2. AV 2 is a firing % or a setpoint depending on the BMS Type setting; as a setpoint it is scaled like a 0-10 V signal between the BMS temperatures set for the low and high analog input.
Does the Lochinvar Armor 1250-4000 water heater (SMART SYSTEM) need a BACnet heartbeat or have a communication timeout?
BAS-written tank temperature and the 0-10 V/rate value must be refreshed every few seconds; parameter H6 ModBus Time sets the timeout (the manual gives 5-120 s with a 10 s default in one place and 1-255 s in another). Other commands such as the enable have a fixed 4-minute timeout. When either timer runs out the heater goes back to its local inputs.
Can the BMS supply sensor values to the Lochinvar Armor 1250-4000 water heater (SMART SYSTEM)?
Set the AV 0 bits for the values the BAS will supply, then write AV 3 tank setpoint and/or AV 4 tank temperature (°C). The tank temperature must be rewritten every few seconds or the heater returns to its own sensor.
How do I check these points on the real Armor 1250-4000 water heater (SMART SYSTEM)?
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
- 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 - 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, Armor Models 1250-4000, Series 100 & 101 · 100305786_2000558371 Rev C · rev. 2022-09. Object names, instances and units are reproduced as published; descriptions are our own.