Attribute Schema Library
Attribute schemaHVACR

Thermostats & Controls Attributes

Thermostats & Controls spans low-voltage room thermostats, line-voltage stats for electric baseboard and unit heaters, communicating room controllers on BACnet MS/TP, humidistats, zone panels, and the temperature and defrost controls on the refrigeration side. Buyers are service techs matching a replacement to an existing subbase, contractors on a rooftop unit, and engineers writing controls submittals.

The data is hard because the fact that decides the sale is the wiring, and the wiring lives in the installation manual, not the spec table. Stage counts arrive as prose. Terminals arrive as a diagram image. The C-wire requirement is a footnote. And one SKU carries two stage configurations, 3H/2C on a heat pump and 2H/2C conventional, which a single-valued field cannot hold.

Three unrelated electrical worlds, 24 VAC, 120-277 VAC line voltage, and millivolt, all get described under one field called "Voltage". The safety listing moved from UL 873 to UL 60730, and catalogs carry both. Rebate and code flags live in external directories keyed by model number, not in the supplier feed.

Core

Every SKU needs these. Without them the record is not a product, it is a row.

Control Type
enum
Low-Voltage Room Thermostat

Separates the three electrical worlds in this category. A line-voltage stat and a 24 VAC stat are never substitutes, and a millivolt job takes neither.

Control Voltage
enum
24 VAC (18-30 VAC)

The first filter on every counter sale. Wiring a 24 VAC stat to a 120 VAC baseboard circuit destroys it on the first call for heat.

Heat Stages
number
3

Buyers filter on it directly. A 1H stat on a two-stage furnace strands the second stage and the equipment never delivers rated capacity.

Cool Stages
number
2

Same filter, opposite mode. Two-stage condensers need Y2; a 1C stat leaves the compressor stuck on low and the space never pulls down.

System Compatibility
enum
Heat Pump with Auxiliary/Emergency Heat

Conventional, heat pump, dual fuel and millivolt are different products. This is the field that stops a heat pump job from buying a furnace stat.

Setpoint Range
range · °F
40-90 °F (4.5-32 °C)

Refrigeration and unit-heater jobs need range below 40 °F or above 90 °F. Residential comfort stats do not go there.

Switch Action / Contact Form
enum
DPST

Line-voltage and mechanical controls live or die on contact form. DPST is required to break both legs of a 240 V circuit.

Manufacturer Part Number
identifier
TH6320U2008

The number the tech reads off the plate on the wall and types into the search bar. Cross-reference and supersession both key off it.

GTIN-12 (UPC)
identifier
12-digit GTIN-12, unpunctuated

Required for every marketplace and reseller feed, and the only identifier that survives a barcode scan at the will-call counter.

Differentiating

What buyers actually compare on. This is where catalogs win or lose the filter.

Terminal Designations
text
R, Rc, W/W1, W2, Y, Y2, G, C, O/B, S1, S2, L/A

The actual compatibility test. A stat with no O/B cannot run a heat pump; no S1/S2 means no outdoor sensor, regardless of stage count.

Power Method / C-Wire Requirement
enum
Battery (2 x AA) or 24 VAC hardwired; C required for Wi-Fi

Decides whether the part can be installed at all. Battery-only, hardwired-with-common, either/or, and power-stealing are four different jobs.

Contact / Load Rating
number · A
22 A @ 120-240 VAC resistive; 18 A @ 277 VAC

Sizes the stat to the load. A 5,000 W baseboard at 240 V draws about 21 A; a 15 A stat there is a nuisance trip waiting to happen.

Communication Protocol
enum
BACnet MS/TP, EIA-485, 9.6-76.8 kbps

Standalone versus networked is a hard fork in the buying process. MS/TP baud support decides whether it drops onto the existing trunk.

Sensor Input Type
enum
10K NTC Type II (10K-2)

10K-2 and 10K-3 are different curves on the same nominal resistance. The wrong one reads off by degrees and never throws a fault.

Control Differential (Deadband)
number · °F
1.0 °F, adjustable 0.5-2.0 °F

Sets short-cycling behavior. Compressor and defrost controls need a wide differential; a tight one on refrigeration kills the equipment.

Compliance & identifiers

Standards, regulatory data, and the identifiers channels reject you for missing.

Agency Listing
enum
UL 60730-1 / UL 60730-2-9; cUL

Inspectors and spec engineers check it. UL 873 is inactive under the UL 60730 transition plan; current listings cite 60730-1 and 60730-2-9.

Enclosure Rating
enum
NEMA 4X

Rooftop, walk-in and washdown locations require NEMA 4X. An indoor NEMA 1 stat in that spot fails and takes the callback with it.

Country of Origin
identifier
MX (ISO 3166-1 alpha-2)

Required for customs entry, marketplace item setup, and any government or Buy American line item.

The fields that aren't in the schema at all

What most thermostats & controls catalogs are missing.

The table above is the schema most catalogs already have. These are the attributes that usually aren't in it — each one surfaced by a signal from the live market rather than by an audit of what's already there. This is what Anglera's Schema Foundry does on a real catalog, in this category.

Supplier signal
+ Terminal Designations

Manufacturer installation PDFs print the terminal block on page 2 as a diagram; distributor spec tables stop at stage count. Buyers searching for a stat with S1/S2 sensor terminals get zero results.

Contractor buys a 3H/2C stat with no O/B terminal for the heat pump changeover. Part goes back, truck rolls twice, and the counter loses the follow-on sale.

Review signal
+ Power Method / C-Wire Requirement

Product Q&A and review threads on every connected stat are dominated by 'does this need a C-wire'. Most distributor records say only 'Power: 24 VAC', which does not answer the question.

The largest single return driver on connected thermostats: the wall gets opened, no common conductor is present, and the part comes back used and unsellable.

Search signal
+ ENERGY STAR / CEC JA5 OCST certification flags

Buyers search for Title 24 compliant and rebate-eligible thermostats and get keyword noise, because the certification exists only in the CEC OCST directory and the ENERGY STAR product finder.

Rebate-driven jobs go to whoever can prove eligibility on the product page. The contractor sources the compliant SKU elsewhere and takes the rest of the order with it.

Supplier signal
+ Sensor Input Type (10K-2 vs 10K-3)

Sensor and thermowell accessory pages spec '10K Type II (10K-2)' or 'Type III (10K-3)'. The stat and controller pages that consume them say only '10K thermistor'. The curves differ.

Mismatched curve reads several degrees off across the range and never faults. Tech blames the control, RMAs a working part, and the space still misses setpoint.

Competitor signal
+ BACnet BTL Listing & Device Profile

Controls specialists expose device profile on their filter rails, and engineers write 'BTL Listed, B-ASC minimum' into Division 23 09 23 submittals. General HVACR catalogs have no such field.

Submittal comes back rejected as not per spec. The engineer substitutes a competitor's part and the distributor loses the whole controls package.

How Schema Foundry finds these

Messy in, governed out.

The same value, spelled every way HVACR suppliers spell it. A filter only works once they agree.

Stage Configuration
3H/2C3 Heat / 2 Cool3H2CMulti-Stage (3/2)2-stage heat/2-stage coolHeat: 3, Cool: 2
Heat Stages: 3 | Cool Stages: 2

One string can't answer 'show me 2+ cool stages'. Split into integers, and carry a set per system type - HP and conventional differ.

Control Voltage
24V24 VAC24 Volts AC18-30 VACLow Voltage24VAC/DC
24 VAC

'Low Voltage' is a class, not a voltage. 18-30 VAC is the tolerance band, not the nominal. Both get shipped in the same column.

Switch Action / Contact Form
SPSTS.P.S.T.Single Pole Single Throw1 pole, 1 throwSPST-NOSPDT (1 Form C)
SPST

Contact form and NO/NC state are two facts. Suppliers fuse them into one string, so an SPST filter silently drops SPST-NO parts.

Setpoint Range
40-90F40°F to 90°F4.5-32C40 to 90 deg F45-95 °F (7-35 °C)Range: 40/90
40-90 °F (min 40, max 90)

Text can't drive a slider, and suppliers mix °F and °C in one feed. Store numeric min/max plus unit; render the display string from it.

What buyers ask

Every one of these should be answerable from the attributes above. If it isn't, that's a gap.

  • Does this need a C-wire, or will it run on batteries?
  • Will it run a two-stage heat pump with electric strip backup?
  • Is O/B changeover field-selectable, or is it fixed?
  • How many amps will this switch at 240 V on a baseboard circuit?
  • Will it work on a millivolt gas valve with no external power?
  • Is it BTL listed as a B-ASC, and what MS/TP baud rates does it do?
  • Does it take a 10K Type II sensor, or does it need Type III?
  • Is this model on the CEC OCST list for Title 24?

What channels require

The same SKU, different mandatory fields per destination.

Distributor's own site (counter + web filter rail)
Control TypeControl VoltageHeat StagesCool StagesSystem CompatibilityPower Method / C-Wire Requirement
Amazon Business
GTIN-12 (UPC)MPNBrandCountry of OriginControl VoltageSystem Compatibility
Grainger / MRO reseller item setup
MPNGTIN-14Country of OriginUNSPSC codeSetpoint RangeAgency Listing
Division 23 09 23 controls submittal
Agency Listing (UL 60730)BTL Listing & Device ProfileCommunication ProtocolSetpoint RangeEnclosure RatingTerminal Designations

Thermostats & Controls data, in practice

Why do some records say UL 873 and others say UL 60730?

UL 873, Temperature-Indicating and -Regulating Equipment, was the legacy listing for thermostats and HVAC temperature controls. It was declared inactive in October 2018 under the UL 60730 series transition plan and has been replaced by UL 60730-1 together with UL 60730-2-9 for automatic electrical temperature sensing controls. Both strings are still in circulation, because catalog records were copied from datasheets printed before the transition and never revisited. Store the listing as a governed value carrying the standard number, not free text, so an engineer filtering for UL 60730-2-9 does not miss parts whose data was simply never refreshed.

Should stage configuration be one field or several?

Several. '3H/2C' as a single string cannot answer 'show me stats with two or more cool stages', which is the filter buyers actually use. Model Heat Stages and Cool Stages as integers. Then model them per system type, because one SKU is legitimately 3H/2C as a heat pump and 2H/2C as a conventional system: same part, two different answers. That is a repeating group, not a second column. Keep the '3H/2C' string if merchandising wants it on the tile, but derive it from the integers so the two can never drift apart.

What is JA5 / OCST, and does it belong in the schema?

In California, Title 24 Part 6 recognises a thermostat as an Occupant Controlled Smart Thermostat only if the manufacturer has certified to the California Energy Commission that it meets Joint Appendix JA5, which includes automatically responding to a demand response signal over a protocol such as OpenADR 2.0 by shifting setpoint. The CEC publishes the declarations, split into OCST Device (all-in-one) and OCST System (a specific set of products installed together). It belongs in the schema as a boolean plus the declaration type. It is keyed by model number in an external directory, so nothing in the supplier feed will ever tell you.

Why is C-wire requirement its own field when 'Power: 24 VAC' is already there?

Because '24 VAC' describes the control circuit, not what the stat needs to stay alive. Four distinct cases hide behind it: battery-only, hardwired requiring a common conductor, either/or, and power-stealing off the Y/W legs. A fifth case, a millivolt gas valve producing roughly 750 mV, will not run a powered stat at all. The contractor cannot tell which case applies until the old stat is off the wall and the bundle is exposed. Modelling Power Method as an enum and C-Wire Required as a boolean answers it before the part leaves the counter, which is where the return would otherwise start.

More HVACR schemas

Air FiltersAir HandlersCondensing UnitsDuct & FittingsHeat ExchangersRefrigerant Line Sets

Run this against your own thermostats & controls.

Bring the category. We'll show you which of these attributes your catalog is missing — and the ones we find that aren't on this page yet.

Book a demo