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Water-to-water heat pump controller · BACnet points list

Carrier W2W Open BACnet points list

Updated 4 November 2026

Short answer

W2W Open is Carrier's i-Vu Open controller for water-to-water heat pumps. It heats or cools the load water to a chilled or hot water supply setpoint with up to 4 capacity stages, and DIP switches select BACnet MS/TP (the default), BACnet ARC156, Modbus or N2 (LonWorks by option card). The list has 76 objects: water setpoints and temperatures, compressor capacity and stages, pump status, enables, OA reset and demand-level settings, alarms and the 'system' points a BAS writes.

This page lists 76 BACnet objects for the Carrier W2W Open — 28 of them writable — with each object’s type, instance number, name, engineering units and access. It is re-typed from Carrier’s own free documentation, linked below.

Manufacturer
Carrier
Model
W2W Open
Equipment
Water-to-water heat pump controller
Equipment type
Heat pumps
BACnet objects
76 (28 writable)
Transport
BACnet MS/TP, BACnet ARC156
Firmware
Not stated
Default device instance
16101xx (xx = rotary switch address)
Also known as
Water-to-Water Open, OPN-WSHPW2WM, Carrier water-to-water heat pump controller, 11-808-538-01
Source document
W2W Open Integration Guide (Appendix A: Network Points List for W2W Open) · 11-808-538-01 · rev. 2021-06-15

Instance calculator. This list prints one unit; the other units follow a formula. Carrier Open controllers (RTU Open, WSHP Open, UPC Open...) instance calculator →

Download CSV 76 rows Download EDE B.I.G.-EU JSON Manufacturer PDF ↗ Compare with your scan Download Easy BACnet Mobile App Google Play

Reference only, provided as-is: verify against Carrier’s current documentation and the live device before use. Not official Carrier information. Terms of use.

BMS integration notes: Carrier W2W Open

Integration in brief

Set the controller for BACnet MS/TP with its DIP switches and rotary address. The unit is occupied by default and holds the load water at the chilled or hot water supply setpoint; the BAS commands occupancy through keypad_ovrde and writes the water setpoints. Outdoor air, T1 or water temperatures from the BMS go into the system_* points at priority 16.

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.

ObjectNameWhyAccess
MV 1001keypad_ovrdeBAS occupancy command: occupied/unoccupiedWrite
BV 9001shutdownNetwork shutdown commandWrite
AV 3024chws_setpointChilled water supply setpointWrite
AV 3023hws_setpointHot water supply setpointWrite
MV 2002run_statusCurrent system modeRead
AV 1020lvg_load_wtr_tempLeaving load water temperatureRead
AV 1019ent_load_wtr_tempEntering load water temperatureRead
AV 5002total_comp_capTotal compressor capacity, %Read
BV 7013comp_alarmCompressor status alarmRead
BV 7048equip_alarmGeneral equipment alarmRead

Enable & remote start

The controller is occupied by default. A third-party BAS sets occupancy by writing BAS On/Off keypad_ovrde (MSV:1001): 1=Inactive, 2=Occupied, 3=Unoccupied; the sequence says this takes precedence over the other occupancy sources, while the system-point table says occupancy control must be set to 3 (BAS On/Off). No heating or cooling runs while unoccupied. Cool Enable (BV:1011) and Heat Enable (BV:1012) must be Enable; Shutdown (BV:9001) stops the unit.

Heartbeat & communication loss

No general heartbeat. The guide gives refresh windows for the generic system points (OAT 5 min / 60 min, space RH 5 min / 10 min); a network value is only used while it is refreshed in time.

Sensors & values from the BMS

Write system_oat (AV:1901), system_rh (AV:1904), system_t1_temp (AV:1909) or the system water temperatures (AV:1910-1912) at BACnet priority 16, no more than once a minute. The controller clears a system point after processing it, so confirm a write by reading the control point (e.g. oa_temp, space_rh) at least 30 s later. System T1 is needed when Control Mode Selection uses T1 for heat/cool changeover.

Network setup

Watch out for

Carrier W2W Open 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.

76 of 76 shown
Type
AnalogBinaryMulti-state
Access
Show
Carrier W2W Open BACnet Points List
DescriptionStates
AV2020comp_stagesActive Compressor StagesRead
AVmin3024chws_setpointChilled Water Supply Setpoint (default 44)°FWrite
AV5001comp_capCompressor Capacity%Read
AV9002oat_cl_lockoutCooling Lockout Temperature (default 45)°FWrite
AV3005eff_cl_stptEffective Cool Setpoint°FRead
AV3006eff_ht_stptEffective Heat Setpoint°FRead
AVmin1019ent_load_wtr_tempEntering Load Water Temp°FRead
AV9003oat_ht_lockoutHeating Lockout Temperature (default 65)°FWrite
AVmin1020lvg_load_wtr_tempLeaving Load Water Temp°FRead
AV9037max_cw_resetMaximum OA CHW Reset (default 10)°FWrite
AV1003oa_tempOutdoor Air Temperature°FRead
AV9007start_delayPower Fail Restart Delay (default 5)secondsWrite
AV1011space_rhSpace Relative Humidity%rhRead
AV1910system_elwtSystem Entering Load Water Temp (default -999)degWrite
AV1911system_ecwtSystem Entering Source Water Temp (default -999)degWrite
AV80001mstr_oa_tempSystem OAT Master°FRead
AV1901system_oatSystem Outdoor Air Temperature (default -999)°FWrite
AV1909system_t1_tempSystem T1 Temperature (default -999)°FWrite
AVmin5002total_comp_capTotal System Cmpr Capacity%Read
BV1011cl_enableCool Enable (default Active (1))Write0=Disable, 1=Enable
BV1023clg_stpt_oa_rst_enaCooling Setpoint OA Reset (default Inactive (0))Write0=Disable, 1=Enable
BV7041ent_lwt_failEntering Load Water Temp Sensor alarmRead0=Normal, 1=Alarm
BV7040elwt_alarmEntering Load Water Temperature alarmRead0=Normal, 1=Alarm
BV1012ht_enableHeat Enable (default Active (1))Write0=Disable, 1=Enable
BV1024htg_stpt_oa_rst_enaHeating Setpoint OA Reset (default Inactive (0))Write0=Disable, 1=Enable
BV7043llwt_alarmLeaving Load Water Temperature alarmRead0=Normal, 1=Alarm
BV7042lvg_cwt_failLeaving Source Water Temp Sensor alarmRead0=Normal, 1=Alarm
BV1019load_pumpLoad Water PumpRead0=Off, 1=On
BV2008occ_statusOccupancy StatusRead0=Unoccupied, 1=Occupied
BV7036oat_alarmOutdoor Air Temperature alarmRead0=Normal, 1=Alarm
BV1020rh_clg_stpt_rstRH Cooling Setpoint Reset (default Inactive (0))Write0=Normal, 1=Alarm
BVmin9001shutdownShutdown (default Inactive (0))Write0=Normal, 1=Alarm
BV1021pump_iso_vlvSource Water PumpRead0=Off/Close, 1=On/Open
BV7027cwt_alarmSource Water Temperature alarmRead0=Normal, 1=Alarm
BV7018sprh_hi_alarmSpace Relative Humidity alarmRead0=Normal, 1=Alarm
BV7022sprh_sensor_failSpace Relative Humidity Sensor alarmRead0=Normal, 1=Alarm
BV7032spt_sensor_failSPT Sensor alarmRead0=Normal, 1=Alarm
BV7046t1_failSystem T1 Sensor alarmRead0=Normal, 1=Alarm
MVmin1001keypad_ovrdeBAS On / Off (default 2)Write1=Inactive, 2=Occupied, 3=Unoccupied
MVmin2002run_statusSystem ModeRead1=Off, 2=Fan Only, 3=Economize, 4=Cooling, 5=Heating, 6=Cont Fan, 7=Test, 8=Start Delay, 9=Temer SAT, 10=Safety Shutdown, 11=Shutdown, 12=IAQ Override, 13=Dehumidify, 15=Pump Only
AVmin3023hws_setpointHot Water Supply Setpoint (default 120)°FWrite
AV1912system_llwtSystem Leaving Load Water Temp (default -999)degWrite
BV7044lvg_lwt_failLeaving Load Water Temp Sensor alarmRead0=Normal, 1=Alarm
AV1017cwl_tempLeaving Source Water Temp°FRead
BV7029oat_failOutdoor Air Temp Sensor alarmRead0=Normal, 1=Alarm
AV9038max_hw_resetMaximum OA HW Reset (default 20)°FWrite
AV1904system_rhSystem Space RH (default -999)%Write
AV3016eff_stptWater Temperature Setpoint°FRead
AV3011occ_dehum_stptOcc Relative Humidity Setpoint (default 60)%rhWrite
AV88001total_comp_stgTotal Req Sys Comp StgsRead
BV7055zs_config_failZS Sensor Configuration alarmRead0=Normal, 1=Alarm
BVmin7013comp_alarmCompressor Status alarmRead0=Normal, 1=Alarm
BV2702loop_pumpLoop Pump StatusRead0=Off, 1=On
BV7049sw_flow_alarmSource Water Flow alarmRead0=Normal, 1=Alarm
BV7057load_flow_alarmLoad Water Flow alarmRead0=Normal, 1=Alarm
BV7045sys_ecwt_failSystem Entering Source Water Temp FailRead0=Normal, 1=Alarm
AV9006cool_demand_levelSystem Cooling Demand LevelRead
AV9036heat_demand_levelSystem Heating Demand LevelRead
AV3020h_dmd1_adjDemand Level 1 Heat Adj (default 3)°FWrite
BV2701cw_link_statusSource Water LinkageRead0=Inactive, 1=Active
AV3017c_dmd1_adjDemand Level 1 Cool Adj (default 3)°FWrite
AV3018c_dmd2_adjDemand Level 2 Cool Adj (default 3)°FWrite
AV3019c_dmd3_adjDemand Level 3 Cool Adj (default 4)°FWrite
BV7047mr_comm_failCommunications with Master alarmRead0=Normal, 1=Alarm
AV3021h_dmd2_adjDemand Level 2 Heat Adj (default 5)°FWrite
AV2701link_cwtWater Loop Temp°FRead
BV7031cond_water_linkage_failSource Water Linkage alarmRead0=Normal, 1=Alarm
AV3022h_dmd3_adjDemand Level 3 Heat Adj (default 7)°FWrite
BV7056load_pmp_comm_failLoad Water Flow Comm alarmRead0=Normal, 1=Alarm
AV2024loop_requestLoop Pump RequestRead
BV7058src_pmp_comm_failSource Water Flow Comm alarmRead0=Normal, 1=Alarm
BVmin7048equip_alarmEquipment AlarmRead0=Normal, 1=Alarm
BV7024safety_alarmSafety alarmRead0=Normal, 1=Alarm
MV2004fan_runFan / SpeedRead1=Off, 2=Low, 3=Med, 4=High, 5=On
MV2009start_typeOptimal Start Type (default (2) Temp Compensated)Write1=None, 2=Temp Compensated, 3=Learning Adaptive
MV2003spt_statusSpace Temp SourceRead1=Sensor Failure, 2=SPT Sensor, 3=RAT / T55, 4=Network, 5=Airside Linkage, 6=Locked Value, 7=T-Stat Linkage, 8=ZS Sensor
Object ID lookup: Carrier W2W Open point IDs by name

Integration notes

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 W2W Open 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 Carrier W2W Open

How many BACnet points does the Carrier W2W Open have?

This list has 76 BACnet objects: 37 analog values, 34 binary values, 5 multi-state values. The exact set on a given unit depends on its firmware, installed options and configuration.

Which Carrier W2W Open BACnet points are writable?

28 of the 76 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 Carrier W2W Open BACnet documentation?

The source is W2W Open Integration Guide (Appendix A: Network Points List for W2W Open) (11-808-538-01), revision 2021-06-15, published free by Carrier at https://www.shareddocs.com/hvac/docs/1000/Public/05/11-808-538-01.pdf.

What are the minimum BACnet points to integrate the Carrier W2W Open?

Start with MV 1001 keypad_ovrde (BAS occupancy command: occupied/unoccupied); BV 9001 shutdown (Network shutdown command); AV 3024 chws_setpoint (Chilled water supply setpoint); AV 3023 hws_setpoint (Hot water supply setpoint); MV 2002 run_status (Current system mode); AV 1020 lvg_load_wtr_temp (Leaving load water temperature); AV 1019 ent_load_wtr_temp (Entering load water temperature); AV 5002 total_comp_cap (Total compressor capacity, %); BV 7013 comp_alarm (Compressor status alarm); BV 7048 equip_alarm (General equipment alarm).

How do I enable BMS control of the Carrier W2W Open?

The controller is occupied by default. A third-party BAS sets occupancy by writing BAS On/Off keypad_ovrde (MSV:1001): 1=Inactive, 2=Occupied, 3=Unoccupied; the sequence says this takes precedence over the other occupancy sources, while the system-point table says occupancy control must be set to 3 (BAS On/Off). No heating or cooling runs while unoccupied. Cool Enable (BV:1011) and Heat Enable (BV:1012) must be Enable; Shutdown (BV:9001) stops the unit.

Does the Carrier W2W Open need a BACnet heartbeat or have a communication timeout?

No general heartbeat. The guide gives refresh windows for the generic system points (OAT 5 min / 60 min, space RH 5 min / 10 min); a network value is only used while it is refreshed in time.

Can the BMS supply sensor values to the Carrier W2W Open?

Write system_oat (AV:1901), system_rh (AV:1904), system_t1_temp (AV:1909) or the system water temperatures (AV:1910-1912) at BACnet priority 16, no more than once a minute. The controller clears a system point after processing it, so confirm a write by reading the control point (e.g. oa_temp, space_rh) at least 30 s later. System T1 is needed when Control Mode Selection uses T1 for heat/cool changeover.

How do I check these points on the real W2W Open?

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 Carrier BACnet points lists

Source: W2W Open Integration Guide (Appendix A: Network Points List for W2W Open) · 11-808-538-01 · rev. 2021-06-15. Object names, instances and units are reproduced as published; descriptions are our own.