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Snow melting controller (boiler-fed slab) · BACnet points list
Watts tekmar Snow Melting Control 680 BACnet points list
Updated 6 November 2026
The tekmar 680 runs an automatic snow melting system: it watches up to two slab and snow/ice sensors, fires a boiler and drives mixing, and talks BACnet IP or BACnet MS/TP natively. The object list gives operation and status codes, melt time remaining, slab, boiler and system temperatures, outputs, flow, pressure, run hours and the error code, plus writable melt/idle/storm setpoints, times, sensitivities and melt/storm requests.
This page lists 52 BACnet objects for the Watts tekmar Snow Melting Control 680 — 18 of them writable — with each object’s type, instance number, name, engineering units and access. It is re-typed from Watts’s own free documentation, linked below.
- Manufacturer
- Watts
- Model
- tekmar Snow Melting Control 680
- Equipment
- Snow melting controller (boiler-fed slab)
- Equipment type
- Boilers & water heaters
- BACnet objects
- 52 (18 writable)
- Transport
- BACnet IP, BACnet MS/TP
- Firmware
- J1243F (PICS)
- Also known as
- tekmar 680, Snow Melting Control 680, 680, tekmar snow melt 680, J1243F
Reference only, provided as-is: verify against Watts’s current documentation and the live device before use. Not official Watts information. Terms of use.
BMS integration notes: Watts tekmar Snow Melting Control 680
Use Melt/Stop Request to start or stop a melt and Storm/Stop Request for storm mode, and adjust the melt, idle and storm setpoints as needed. Read Operation and Operation Status, slab and boiler temperatures, the snow/ice sensor states and the error code.
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 |
|---|---|---|---|
| BV 1 | Melt/Stop Request | Start melting from the BMS (1 = Melt) | Write |
| BV 2 | Storm/Stop Request | Start storm mode from the BMS (1 = Storm) | Write |
| AV 1 | Melt Setpoint | Slab melting setpoint, 32-95 °F | Write |
| AV 0 | BAS Outdoor Air Temperature | Outdoor temperature from the BMS (if BV 0 = 1) | Write |
| BV 0 | Outdoor Sensor Enable | 1 = use the BMS outdoor temperature | Write |
| AI 0 | Operation | 0 Off, 1 Idle, 2 Storm, 3 Melt, 4 Manual | Read |
| AI 1 | Operation Status | Normal, WWSD, CWSD, timed melt, warming up | Read |
| AI 7 | Coldest Slab Temperature | Coldest slab temperature | Read |
| BI 2 | Combined Water Status | Combined snow/ice sensor state (1 = wet) | Read |
| AI 26 | Error Code | Error code; see the error list | Read |
Enable & remote start
BV 1 Melt/Stop Request (1 = Melt) and BV 2 Storm/Stop Request (1 = Storm) start a melt or storm cycle from the BMS. BV 3-6 enable or disable idling, storm mode, warm weather shut down and cold weather cut out.
Sensors & values from the BMS
Set BV 0 Outdoor Sensor Enable = 1 so the 680 uses the BAS outdoor temperature written to AV 0 (-67 to 149 °F); with 0 it measures its own outdoor sensor.
Network setup
- The 680 supports BACnet IP (RJ45 port) and BACnet MS/TP (RS-485 A, B, Gnd terminals); Modbus RS-485 is the other option.
- MS/TP: do not tie Gnd to the enclosure ground screws; with 120 ohm terminators, bias resistors are needed at the BACnet master.
- DeviceCommunicationControl password is "tekmar" (from the PICS).
Watch out for
- Time values (melt time, storm run time) are in hours with minutes, e.g. 0:30 to 24:00.
- Idle Setpoint and Storm Setpoint use 0 = off.
- The manual prints Melting Energy with the same ID as System Pressure (AI 19); it is left out here (see notes).
Watts tekmar Snow Melting Control 680 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 | |||||
|---|---|---|---|---|---|---|
| AImin | 0 | Operation | Read | 0=Off, 1=Idle, 2=Storm, 3=Melt, 4=Manual Override | ||
| AImin | 1 | Operation Status | Read | 0=Normal, 1=WWSD, 2=CWSD, 3=Timed Melting, 4=Warming Up, 5=Pending | ||
| AI | 2 | Melt Time Remaining | Range 0 to 24:00 hours | h | Read | |
| AI | 3 | Additional Melt Time Remaining | Range 0 to 6:00 hours | h | Read | |
| AI | 4 | Outdoor Air Temperature | Range -67 to 149°F | °F | Read | |
| AI | 5 | Slab 1 Temperature | Range -58 to 167°F | °F | Read | |
| AI | 6 | Slab 2 Temperature | Range -58 to 167°F | °F | Read | |
| AImin | 7 | Coldest Slab Temperature | Range -58 to 167°F | °F | Read | |
| AI | 8 | Slab Target Temperature | Range 20 to 120°F | °F | Read | |
| AI | 9 | Boiler Supply Temperature | Range -31 to 266°F | °F | Read | |
| AI | 10 | Boiler Return Temperature | Range -31 to 266°F | °F | Read | |
| AI | 11 | Boiler Target Temperature | Range 50 to 230°F | °F | Read | |
| AI | 12 | Boiler Output | Range 0 to 100% | % | Read | |
| AI | 13 | System Supply Temperature | Range -31 to 266°F | °F | Read | |
| AI | 14 | System Return Temperature | Range -31 to 266°F | °F | Read | |
| AI | 15 | Mix System Target Temperature | Range 50 to 230°F | °F | Read | |
| AI | 16 | Mix System Output | Range 0 to 100% | % | Read | |
| AI | 17 | PWM and Electric Heat Output | Range 0 to 100% | % | Read | |
| AI | 18 | System Flow Rate | Range 0 to 1000 GPM | gpm | Read | |
| AI | 19 | System Pressure | Range 0 to 300 psi | psi | Read | |
| AI | 21 | Melting Hours | Range 0 to 65535 Hours | h | Read | |
| AI | 22 | Heat Cycles | Range 0 to 65535 Cycles | Read | ||
| AI | 23 | System Pump Run Time | Range 0 to 65535 Hours | h | Read | |
| AI | 24 | Primary Pump Run Time | Range 0 to 65535 Hours | h | Read | |
| AI | 25 | Boiler Pump Run Time | Range 0 to 65535 Hours | h | Read | |
| AImin | 26 | Error Code | Code from the error code list in the manual | Read | ||
| AVmin | 0 | BAS Outdoor Air Temperature | Range -67 to 149°F | °F | Write | |
| AVmin | 1 | Melt Setpoint | Range 32 to 95°F | °F | Write | |
| AV | 2 | Idle Setpoint | Range 20 to 95°F, 0 = off | °F | Write | |
| AV | 3 | Storm Setpoint | Range 20 to 95°F, 0 = off | °F | Write | |
| AV | 4 | Manual Melt Time | Range 0:30 to 24:00 Hours | h | Write | |
| AV | 5 | Add Melt Time | Range 0:00 to 6:00 Hours | h | Write | |
| AV | 6 | Storm Run Time | Range 0:30 to 24:00 Hours | h | Write | |
| AV | 7 | Snow/Ice Sensitivity 1 | Write | 0=Auto, 1=Min, 2=-2, 3=-1, 4=Mid, 5=+1, 6=+2, 7=Max | ||
| AV | 8 | Snow/Ice Sensitivity 2 | Write | 0=Auto, 1=Min, 2=-2, 3=-1, 4=Mid, 5=+1, 6=+2, 7=Max | ||
| AV | 9 | Warm Weather Shut Down | Range 32 to 95°F | °F | Write | |
| AV | 10 | Cold Weather Cut Out | Range -30 to 50°F | °F | Write | |
| BI | 0 | Slab 1 Water | Read | 0=Dry, 1=Wet | ||
| BI | 1 | Slab 2 Water | Read | 0=Dry, 1=Wet | ||
| BImin | 2 | Combined Water Status | Read | 0=Dry, 1=Wet | ||
| BI | 3 | System Pump | Read | 0=Off, 1=On | ||
| BI | 4 | Primary Pump | Read | 0=Off, 1=On | ||
| BI | 5 | Boiler Pump | Read | 0=Off, 1=On | ||
| BI | 6 | Boiler Stage 1 | Read | 0=Off, 1=On | ||
| BI | 7 | Boiler Stage 2 | Read | 0=Off, 1=On | ||
| BVmin | 0 | Outdoor Sensor Enable | Write | 0=Control measures outdoor air temperature, 1=BAS sends outdoor air temperature | ||
| BVmin | 1 | Melt/Stop Request | Write | 0=Off, 1=Melt | ||
| BVmin | 2 | Storm/Stop Request | Write | 0=Off, 1=Storm | ||
| BV | 3 | Idle Enable | Write | 0=Idling disabled, 1=Idling enabled | ||
| BV | 4 | Storm Enable | Write | 0=Storm disabled, 1=Storm enabled | ||
| BV | 5 | WWSD Enable | Write | 0=WWSD disabled, 1=WWSD enabled | ||
| BV | 6 | CWCO Enable | Write | 0=CWCO disabled, 1=CWCO enabled |
No points match these filters.
Object ID lookup: Watts tekmar Snow Melting Control 680 point IDs by name
AI0OperationAI1Operation StatusAI2Melt Time RemainingAI3Additional Melt Time RemainingAI4Outdoor Air TemperatureAI5Slab 1 TemperatureAI6Slab 2 TemperatureAI7Coldest Slab TemperatureAI8Slab Target TemperatureAI9Boiler Supply TemperatureAI10Boiler Return TemperatureAI11Boiler Target TemperatureAI12Boiler OutputAI13System Supply TemperatureAI14System Return TemperatureAI15Mix System Target TemperatureAI16Mix System OutputAI17PWM and Electric Heat OutputAI18System Flow RateAI19System PressureAI21Melting HoursAI22Heat CyclesAI23System Pump Run TimeAI24Primary Pump Run TimeAI25Boiler Pump Run TimeAI26Error CodeAV0BAS Outdoor Air TemperatureAV1Melt SetpointAV2Idle SetpointAV3Storm SetpointAV4Manual Melt TimeAV5Add Melt TimeAV6Storm Run TimeAV7Snow/Ice Sensitivity 1AV8Snow/Ice Sensitivity 2AV9Warm Weather Shut DownAV10Cold Weather Cut OutBI0Slab 1 WaterBI1Slab 2 WaterBI2Combined Water StatusBI3System PumpBI4Primary PumpBI5Boiler PumpBI6Boiler Stage 1BI7Boiler Stage 2BV0Outdoor Sensor EnableBV1Melt/Stop RequestBV2Storm/Stop RequestBV3Idle EnableBV4Storm EnableBV5WWSD EnableBV6CWCO Enable
Integration notes
- Native BACnet, vendor ID 585 (tekmar Control Systems), protocol revision 10, device profile B-ASC.
- The manual lists AI 19 twice (System Pressure and Melting Energy, then skips to AI 21). Only System Pressure is listed here because the real instance of Melting Energy is not printed.
- Temperatures are in °F.
- Source PDF is served from Watts' media server (www.watts.com).
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 tekmar Snow Melting Control 680 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 Watts tekmar Snow Melting Control 680
How many BACnet points does the Watts tekmar Snow Melting Control 680 have?
This list has 52 BACnet objects: 26 analog inputs, 11 analog values, 8 binary inputs, 7 binary values. The exact set on a given unit depends on its firmware, installed options and configuration.
Which Watts tekmar Snow Melting Control 680 BACnet points are writable?
18 of the 52 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 Watts tekmar Snow Melting Control 680 BACnet documentation?
The source is Snow Melting Control 680 BAS Integration Manual (680_B), revision 03/20, published free by Watts at https://www.watts.com/dfsmedia/0533dbba17714b1ab581ab07a4cbb521/43041-source/680_b_02.pdf.
What are the minimum BACnet points to integrate the Watts tekmar Snow Melting Control 680?
Start with BV 1 Melt/Stop Request (Start melting from the BMS (1 = Melt)); BV 2 Storm/Stop Request (Start storm mode from the BMS (1 = Storm)); AV 1 Melt Setpoint (Slab melting setpoint, 32-95 °F); AV 0 BAS Outdoor Air Temperature (Outdoor temperature from the BMS (if BV 0 = 1)); BV 0 Outdoor Sensor Enable (1 = use the BMS outdoor temperature); AI 0 Operation (0 Off, 1 Idle, 2 Storm, 3 Melt, 4 Manual); AI 1 Operation Status (Normal, WWSD, CWSD, timed melt, warming up); AI 7 Coldest Slab Temperature (Coldest slab temperature); BI 2 Combined Water Status (Combined snow/ice sensor state (1 = wet)); AI 26 Error Code (Error code; see the error list).
How do I enable BMS control of the Watts tekmar Snow Melting Control 680?
BV 1 Melt/Stop Request (1 = Melt) and BV 2 Storm/Stop Request (1 = Storm) start a melt or storm cycle from the BMS. BV 3-6 enable or disable idling, storm mode, warm weather shut down and cold weather cut out.
Can the BMS supply sensor values to the Watts tekmar Snow Melting Control 680?
Set BV 0 Outdoor Sensor Enable = 1 so the 680 uses the BAS outdoor temperature written to AV 0 (-67 to 149 °F); with 0 it measures its own outdoor sensor.
How do I check these points on the real tekmar Snow Melting Control 680?
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 Watts BACnet points lists
- Digital water mixing station (DHW tempering valve)
Watts IntelliStation 2 digital mixing station
Powers IntelliStation 2 and 2S digital hot-water mixing stations for building domestic hot water systems.
Also known as: Powers IntelliStation 2, IntelliStation 2S, IntelliStation2, 116401 - Snow/ice sensor interface (BAS-run snow melting)
Watts tekmar BACnet Snow/Ice Sensor Interface 681
tekmar (Watts) 681 interface that connects a snow/ice sensor and slab and outdoor sensors to a building automation system for snow melting.
Also known as: tekmar 681, 681, BACnet Snow/Ice Sensor Interface, tekmar snow ice sensor interface, J1297 - Multi-boiler plant controller (boiler staging)
Watts tekmar Boiler Control 284
tekmar Boiler Control 284, which stages and modulates up to four boilers for heating and DHW loads.
Also known as: tekmar 284, Boiler Control 284, 284, tekmar multi-staging 284 - Multi-boiler plant controller
Watts tekmar Smart Boiler Control 294BAC
tekmar (Watts) Smart Boiler Control 294BAC, a staging and reset control for plants of up to 16 boilers with DHW, connected natively over BACnet IP or BACnet MS/TP.
Also known as: tekmar 294BAC, 294BAC, tekmar 294, Smart Boiler Control 294, J1308
Source: Snow Melting Control 680 BAS Integration Manual · 680_B · rev. 03/20. Object names, instances and units are reproduced as published; descriptions are our own.