HVAC Thermostat Selection Guide
The right thermostat has to match your equipment first and your features second — a mismatch means it either won't control your system or won't power on. This guide walks through staging, wiring, and the programmable-vs-smart decision so you order the right one. Shop the range in our thermostats collection.
1. Match the heating & cooling stages
Count the stages your system has and match the thermostat to them:
- 1 Heat / 1 Cool (1H/1C) — standard single-stage furnace + AC.
- 2 Heat / 2 Cool (2H/2C) — two-stage or multi-stage systems, and many heat pumps with aux heat. See the Honeywell T6 Pro (2H/2C).
- Heat pump — needs a thermostat with a reversing-valve (O/B) terminal.
2. Check the wiring — especially the C-wire
Most Wi-Fi and smart thermostats need a common (C) wire for continuous power. Standard 24V systems supply this; confirm you have a C-wire or a battery/power-stealing option before buying. Commercial fan-coil and PTAC units use different wiring — match a purpose-built control like the Johnson Controls FCP-PA-701-B (FCU/PTAC).
3. Pick the feature level
- Non-programmable — simple, reliable, cheapest. Good for rentals and basic setups.
- Programmable — schedule setbacks to cut energy use. See the LuxPro P621U (5/1/1).
- Smart / networked — app control, remote monitoring, and building-automation integration for commercial sites. See the Johnson Controls TEC3630 networked thermostat.
4. Residential vs commercial
Residential thermostats handle standard 24V split systems. Commercial spaces — fan coils, PTACs, RTUs, networked building controls — need commercial-grade thermostats with the right protocols (BACnet/N2) and staging. Match the control to the equipment, not just the room.
Ready to order?
Browse residential and commercial thermostats in the SPLYPRO thermostats collection. Free shipping over $50, most orders out in 1–2 business days. Not sure what fits your system? Call 786-577-2500 or email csr@splypro.com.
| State | Resale Certificate | Charitable | Religious | Educational | Government | Farmer | Miscellaneous |
|---|---|---|---|---|---|---|---|
| Alabama | Multi‑Jurisdiction Form & Sales tax license | AL State‑Issued Certificate of Exemption | AL State‑Issued Certificate of Exemption | Multi‑Jurisdiction Form | Multi‑Jurisdiction Form | Multi‑Jurisdiction Form | Multi‑Jurisdiction Form & Sales tax license |
| Alaska | No Sales Tax State – No need to Apply | ||||||
| Arizona | AZ Form 5000A & Privilege Tax License | AZ Form 5000A & AZ State‑Issued Certificate | AZ Form 5000 & AZ State‑Issued Certificate | AZ Form 5000 & AZ State‑Issued Certificate | AZ Form 5000 & Tribal Card (if applicable) | AZ Form 5000 | AZ Form 5000A & Privilege Tax License |
| Arkansas | Streamlined / AR ST‑391 Form | AR State‑Issued Certificate of Exemption | TAXABLE – NOT ELIGIBLE | TAXABLE – NOT ELIGIBLE | Streamlined / AR ST‑391 Form | Streamlined / AR ST‑391 Form | Streamlined / AR ST‑391 Form & Sales & Use Tax Permit |
| California | Multi‑Jurisdiction / CA Resale Cert & Seller’s Permit | TAXABLE – NOT ELIGIBLE | TAXABLE – NOT ELIGIBLE | TAXABLE – NOT ELIGIBLE | Multi‑Jurisdiction Form & Fed Gov’t letter (Fed. Only) | Multi‑Jurisdiction Form | Multi‑Jurisdiction / CA Resale Cert & Seller’s Permit |
| Colorado | CO DR‑0563 MJ Form, State Sales Tax License & City License | CO DR‑0563 MJ Form, State Exemption Cert & City Exemption Cert | CO DR‑0563 MJ Form, State Exemption Cert & City Exemption Cert | CO DR‑0563 MJ Form, State Exemption Cert & City Exemption Cert | CO DR‑0563 MJ Form, State Exemption Cert & City Exemption Cert | CO DR‑0563 MJ Form, State Exemption Cert & City Exemption Cert | CO DR‑0563 MJ Form, State Sales Tax License & City License |
| Connecticut | Multi‑Jurisdiction / Resale Cert & Sales & Use Tax Permit | Cert 119 & 501(c)(3) letter | Cert 119 & 501(c)(3) letter | Public – Cert 134; Private – Cert 119 & 501(c)(3) letter | CT Cert 134 | State‑Issued Farmer Tax Exemption Permit | Multi‑Jurisdiction / Resale Cert & Sales & Use Tax Permit |
| Delaware | No Sales Tax State – No need to Apply | ||||||
| District of Columbia | Multi‑Jurisdiction Form & Sales Tax License | DC‑Issued Letter of Exemption | DC‑Issued Letter of Exemption | DC‑Issued Letter of Exemption | Multi‑Jurisdiction Form | TAXABLE – NOT ELIGIBLE | Multi‑Jurisdiction Form & Sales Tax License |
| Florida | State‑Issued DR‑13 Certificate | State‑Issued DR‑14 Certificate | State‑Issued DR‑14 Certificate | State‑Issued DR‑14 Certificate | State‑Issued DR‑14 Certificate | State‑Issued DR‑13 Certificate | State‑Issued DR‑13 Certificate |
| Georgia | Streamlined / GA ST‑5 & Sales Tax Certificate of Registration | GA‑State‑Issued Certificate of Exemption | TAXABLE – NOT ELIGIBLE | Streamlined or GA ST‑5 | Streamlined or GA ST‑5 | GA‑State‑Issued Gate Card | Streamlined / GA ST‑5 & Sales Tax Certificate of Registration |
| Hawaii | HI G‑17 Form & General Excise Tax License | HI‑State‑Issued Exemption Letter | HI‑State‑Issued Exemption Letter | TAXABLE – NOT ELIGIBLE | HI G‑17 Form (Federal Only) | HI G‑17 Form | HI G‑17 Form & General Excise Tax License |
| Idaho | ID ST‑101 or Multi‑Jurisdiction & Seller’s Permit | Idaho ST‑101 Form | TAXABLE – NOT ELIGIBLE | Idaho ST‑101 Form | Idaho ST‑101 Form | Idaho ST‑101 Form | ID ST‑101 or Multi‑Jurisdiction & Seller’s Permit |
| Illinois | Multi‑Jurisdiction / IL CRT‑61 & Certificate of Registration | IL‑State‑Issued Certificate of Exemption | IL‑State‑Issued Certificate of Exemption | IL‑State‑Issued Certificate of Exemption | IL‑State‑Issued Certificate of Exemption | Multi‑Jurisdiction Form | Multi‑Jurisdiction / IL CRT‑61 & Certificate of Registration |
| Indiana | IN ST‑105 or Streamlined & Registered Retail Merchant Certificate | IN ST‑105 or Streamlined | IN ST‑105 or Streamlined | IN ST‑105 or Streamlined | IN ST‑105 or Streamlined | IN ST‑105 or Streamlined | IN ST‑105 or Streamlined & Registered Retail Merchant Certificate |
| Iowa | IA Sales Tax Exempt Cert or Streamlined & Retail Sales Tax Permit | IA Sales Tax Exempt Cert or Streamlined (must be on IA Nonprofit list) | IA Sales Tax Exempt Cert or Streamlined | IA Sales Tax Exempt Cert or Streamlined | IA Sales Tax Exempt Cert or Streamlined | IA Sales Tax Exempt Cert or Streamlined | IA Sales Tax Exempt Cert or Streamlined & Retail Sales Tax Permit |
| Kansas | KS PR‑78 Form or Streamlined & Retailer’s Sales Tax Registration | KS PR‑78 Form or Streamlined | KS PR‑78 Form or Streamlined | KS PR‑78 Form or Streamlined | KS PR‑78 Form or Streamlined | KS PR‑78 Form or Streamlined | KS PR‑78 Form or Streamlined & Retailer’s Sales Tax Registration |
| Kentucky | KY 51A105 Form / Streamlined & Sales & Use Tax Permit | KY 51A126 Exemption Cert or Streamlined | KY 51A126 Exemption Cert or Streamlined | KY 51A126 Exemption Cert or Streamlined | KY 51A126 Exemption Cert or Streamlined | KY 51A126 Exemption Cert or Streamlined | KY 51A105 Form / Streamlined & Sales & Use Tax Permit |
| Louisiana | State‑Issued R‑1064 Form & Parish Certificate | LA‑State‑Issued Exemption Letter | TAXABLE – NOT ELIGIBLE | LA R‑1056 Form | LA R‑1056 Form or LA R‑1356 Form | LA R‑1007 Form | State‑Issued R‑1064 Form & Parish Certificate |
| Maine | Maine Resale Certificate | Maine State‑Issued Certificate of Exemption | Maine State‑Issued Certificate of Exemption | Maine State‑Issued Certificate of Exemption | Multi‑Jurisdiction Form (Fed. Only) & ME Exempt. Cert. | ME Exemption Card & ST‑L‑154 / ST‑L‑154A | Maine Resale Certificate |
| Maryland | Multi‑Jurisdiction Form & Sales & Use Tax License | Maryland State‑Issued Exemption Certificate | Maryland State‑Issued Exemption Certificate | Maryland State‑Issued Exemption Certificate | Maryland State‑Issued Exemption Certificate | Maryland State‑Issued Agriculture Exemption Certificate | Multi‑Jurisdiction Form & Sales & Use Tax License |
| Massachusetts | MA ST‑4 Form & Sales & Use Tax Registration | MA ST‑5 Form & State‑Issued ST‑2 Cert. | MA ST‑5 Form & State‑Issued ST‑2 Cert. | MA ST‑5 Form & State‑Issued ST‑2 Cert. | ST‑5 Form & State‑Issued ST‑2 Cert. | ST‑5 Form & State‑Issued ST‑2 Cert. | ST‑12 Form & State‑Issued ST‑2 Cert. |
| Michigan | Streamlined & Sales Tax License | Streamlined & 501(c)(3) letter or MI Exempt Cert | Streamlined & 501(c)(3) letter or MI Exempt Cert | Streamlined & 501(c)(3) letter or MI Exempt Cert | Streamlined & 501(c)(3) letter or MI Exempt Cert | Streamlined & 501(c)(3) letter or MI Exempt Cert | Streamlined & Sales Tax License |
| Minnesota | Streamlined & Sales & Use Tax Permit | Streamlined or MN ST‑3 Form | Streamlined or MN ST‑3 Form | Streamlined or MN ST‑3 Form | Streamlined or MN ST‑3 Form | Streamlined or MN ST‑3 Form | Streamlined & Sales & Use Tax Permit |
| Mississippi | MS Retailer’s Permit | MS‑State‑Issued Exemption Letter | TAXABLE – NOT ELIGIBLE | MS‑State‑Issued Exemption Letter | Multi‑Jurisdiction Form | Multi‑Jurisdiction Form | MS Retailer’s Permit |
| Missouri | Multi‑Jurisdiction / MO Form 149 & Sales tax license | MO‑State‑Issued Exemption Letter | MO‑State‑Issued Exemption Letter | MO‑State‑Issued Exemption Letter | MO Form 149 | MO Form 149 | Multi‑Jurisdiction / MO Form 149 & Sales tax license |
| Montana | No Sales Tax State – No need to Apply | ||||||
| Nebraska | Streamlined & Sales Tax Permit | Streamlined | Streamlined | Streamlined | Streamlined | Streamlined | Streamlined & Sales Tax Permit |
| Nevada | Streamlined & Sales Tax Permit | NV‑State‑Issued Exemption Letter | NV‑State‑Issued Exemption Letter | NV‑State‑Issued Exemption Letter | Streamlined | Streamlined | Streamlined & Sales Tax Permit |
| New Hampshire | No Sales Tax State – No need to Apply | ||||||
| New Jersey | Streamlined & Sales Tax Cert of Authority | State‑Issued ST‑5 Form | State‑Issued ST‑5 Form | Streamlined or Letter from School | Streamlined | Streamlined | Streamlined & Sales Tax Cert of Authority |
| New Mexico | State‑Issued Type 2‑NTTC Form | State‑Issued Type 9‑NTTC Form | State‑Issued Type 9‑NTTC Form | State‑Issued Type 9‑NTTC Form | State‑Issued Type 9‑NTTC Form | Statement of Affirmation from Farmer | State‑Issued Type 2‑NTTC Form |
| New York | NY ST‑120 Form & Sales Tax Cert of Authority | ST‑119.1 Form | ST‑119.1 Form | ST‑119.1 Form or NY AC‑946 Form | Letter from State of NY or NY AC‑946 Form | NY ST‑125 | NY ST‑120 Form & Sales Tax Cert of Authority |
| North Carolina | Streamlined / E‑595E Form & Certificate of Registration | TAXABLE – NOT ELIGIBLE | TAXABLE – NOT ELIGIBLE | TAXABLE – NOT ELIGIBLE | Streamlined / E‑595E Form | Streamlined / E‑595E Form | Streamlined / E‑595E Form & Certificate of Registration |
| North Dakota | Streamlined & Sales & Use Tax Permit | Streamlined | Streamlined | Streamlined | Streamlined | Streamlined | Streamlined & Sales & Use Tax Permit |
| Ohio | OH Blanket Form & Ohio Vendor License | OH Blanket Form | OH Blanket Form | OH Blanket Form | OH Blanket Form | OH Blanket Form | OH Blanket Form & Ohio Vendor License |
| Oklahoma | Streamlined & Sales Tax Permit | Streamlined & State‑Issued Exemption Cert | Streamlined & State‑Issued Exemption Cert | Streamlined & State‑Issued Exemption Cert | Streamlined | Streamlined Agriculture Card | Streamlined & Sales Tax Permit |
| Oregon | No Sales Tax State – No need to Apply | ||||||
| Pennsylvania | PA REV‑1220 Exemption Cert & Sales Tax License | PA REV‑1220 Exemption Cert | PA REV‑1220 Exemption Cert | PA REV‑1220 Exemption Cert | PA REV‑1220 Exemption Cert | PA REV‑1220 Exemption Cert | PA REV‑1220 Exemption Cert & Sales Tax License |
| Rhode Island | Streamlined / Resale Cert & Sales Tax License | Streamlined or State‑Issued Exemption Cert | Streamlined or State‑Issued Exemption Cert | Streamlined or State‑Issued Exemption Cert | Streamlined or State‑Issued Exemption Cert | Streamlined or State‑Issued Exemption Cert | Streamlined / Resale Cert & Sales Tax License |
| South Carolina | Multi‑Jurisdiction Form & SC Retail License | SC‑State‑Issued ST‑9 Certificate | SC‑State‑Issued ST‑9 Certificate | SC‑State‑Issued ST‑9 Certificate | Multi‑Jurisdiction Form | SC ST‑8F Form | Multi‑Jurisdiction Form & SC Retail License |
| South Dakota | Streamlined & Sales tax license | Streamlined & State‑Issued Exemption Cert | Streamlined & State‑Issued Exemption Cert | Streamlined & State‑Issued Exemption Cert | Streamlined | Streamlined | Streamlined & Sales tax license |
| Tennessee | Certificate of Resale or Streamlined | TN‑State‑Issued Certificate of Exemption | TN‑State‑Issued Certificate of Exemption | TN‑State‑Issued Certificate of Exemption or Streamlined | TN‑State‑Issued Certificate of Exemption or Streamlined | Certificate of Resale or Streamlined | Certificate of Resale or Streamlined |
| Texas | TX Resale Certificate & Sales & Use Tax Permit | TX Exemption Certificate & Comptroller Letter | TX Exemption Certificate & Comptroller Letter | TX Exemption Certificate & Comptroller Letter | TX Exemption Certificate | TX Agriculture Exemption Certificate | TX Resale Certificate & Sales & Use Tax Permit |
| Utah | Utah TC‑721 Form & Sales Tax License | Utah TC‑721 Form | Utah TC‑721 Form | Utah TC‑721 Form | Utah TC‑721 Form | Utah TC‑721 Form | Utah TC‑721 Form & Sales Tax License |
| Vermont | Streamlined & Sales Tax License | Streamlined | Streamlined | Streamlined | Streamlined | Streamlined | Streamlined & Sales Tax License |
| Virginia | VA ST‑10 Form & Certificate of Registration | VA State‑Issued Exemption Cert | VA ST‑13A Form | VA ST‑12 Form | VA ST‑12 Form | VA ST‑18 Form | VA ST‑11 Form |
| Washington | Reseller Permit | Reseller Permit | Reseller Permit | TAXABLE – NOT ELIGIBLE | Streamlined (Federal) | Reseller Permit or Farmer’s Cert | Reseller Permit |
| West Virginia | Streamlined & Business Registration Certificate | Streamlined | Streamlined | Streamlined | Streamlined | Streamlined | Streamlined & Business Registration Certificate |
| Wisconsin | Streamlined & Seller’s Certificate of Registration | Streamlined | Streamlined | Streamlined | Streamlined | Streamlined | Streamlined & Seller’s Certificate of Registration |
| Wyoming | Streamlined & Sales & Use Tax License | Streamlined | Streamlined | Streamlined | Streamlined | Streamlined | Streamlined & Sales & Use Tax License |