Thermostats & Zoning: Smart, Wi-Fi, Line Voltage & Zoning Controls
Voomi Supply carries residential and commercial thermostats, including Wi-Fi smart thermostats, programmable and non-programmable models, line voltage thermostats, and zoning system controls, from brands like Honeywell, Carrier, Goodman, Rheem, and Robertshaw. Shop in-stock thermostats with detailed technical specifications on every listing, plus US-based support to help match the right stage count, voltage, and control type to your HVAC or heat pump system.
Smart & Wi-FiConventional & heat pump compatible
Same-DayShipping on in-stock orders
US SupportHelp matching stages & wiring
30-DayReturns on most items
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CARRIER
Carrier SYSTXCCWIC01-C Infinity Touch Control with Wi-Fi
$806.18
In stock
HONEYWELL
Honeywell YTHX1200B8 ElitePRO S1200 Smart Thermostat W/ EIM (4H/2C Heat Pump & 3H/3C Conventional)
$340.59
In stock
RESIDEO
Honeywell THX321WFS3001W/U Smart Wi-Fi Programmable Thermostat with Room Sensor 24 VAC
$285.81
In stock
GOODMAN
Goodman GTST-CW-WH-A GTST Smart Thermostat 4H/2C
$204.57
In stock
HONEYWELL
Honeywell TB6575A1000/U Fan Coil Thermostat Line Voltage White
$180.95
In stock
AVANTCO
Avantco 400044 Thermostat Rx, 3/8 X 6, 24
$156.79
$131.22
In stock
HONEYWELL
Honeywell TH1210DH1001/U PRO 1000 Non-Programmable Thermostat
$66.85
In stock
Brands we carry
Types of thermostats
Thermostats are grouped by control voltage and how they schedule temperature, both of which need to match the HVAC system they're controlling.
| Type | How it works | Best for |
|---|---|---|
| Wi-Fi / smart | Connects to a home network for remote control, scheduling, and app-based monitoring | Homeowners who want remote access and usage tracking |
| Programmable | Runs on-device schedules without needing an internet connection | Predictable routines without app dependency |
| Non-programmable | Simple manual temperature control with no scheduling | Rentals, simple systems, or straightforward replacements |
| Line voltage | Switches high-voltage loads directly, commonly used with baseboard or fan coil units | Electric baseboard heat and fan coil systems |
| Pneumatic | Uses compressed air rather than electricity to control HVAC equipment | Older commercial buildings with existing pneumatic control systems |
Understanding heat and cool stages
A thermostat's stage rating (like "2H/2C" or "4H/2C") describes how many heating and cooling stages it can control, and it must match or exceed what the HVAC system uses.
| System type | Typical stage rating |
|---|---|
| Standard single-stage furnace or AC | 1H/1C |
| Two-stage conventional system | 2H/2C |
| Heat pump with backup heat | 2H/1C up to 4H/2C, depending on backup stages |
| Zoned or multi-stage commercial system | 3H/3C or higher |
Heat pump systems are rated differently from conventional gas or electric systems because backup electric heat adds stages, so always check the equipment's stage rating before choosing a thermostat.
Things to consider before you buy
- Confirm the thermostat's heat/cool stage rating matches or exceeds your system's requirements
- Check wiring compatibility, including whether your system has a C-wire for Wi-Fi thermostats that need continuous power
- Line voltage thermostats switch high-voltage loads directly and require different wiring than low-voltage 24V models
- Confirm heat pump vs. conventional system compatibility, since staging works differently between the two
- Installation involving line voltage wiring should be handled by a licensed electrician or HVAC technician
Thermostats & zoning glossary
- C-wire
- A common wire that provides continuous 24V power to a thermostat, often required for Wi-Fi and smart models. Shop Wi-Fi thermostats →
- Stages (H/C)
- The number of heating and cooling levels a thermostat can control, such as 2H/2C. Shop programmable thermostats →
- Line voltage
- A control type that switches high-voltage loads directly, commonly 120V or 240V, rather than low-voltage 24V signals. Shop line voltage thermostats →
- Zoning
- A system that divides a building into separate areas, each independently controlled for temperature. Shop thermostats & zoning →
- Changeover
- The function that switches a system between heating and cooling mode, either manually or automatically. Shop programmable thermostats →
- Room sensor
- A remote sensor that reports temperature from a different location than the thermostat itself, used to balance comfort across a home. Shop Wi-Fi thermostats →
Frequently asked questions
Why won't my new thermostat turn on my heat or AC?
This is usually one of three things: a wiring mismatch, a missing C-wire on a Wi-Fi model, or a stage mismatch between the thermostat and the equipment. First confirm each wire is connected to the matching terminal shown in the installation manual, since a swapped wire is the most common cause of a system not responding. If the thermostat powers on but the system never engages, check whether it needs a C-wire for continuous power, since some smart thermostats will run on battery but can't reliably call for heat or cooling without one. If wiring and power check out, confirm the thermostat's heat/cool stage rating actually matches your equipment, since an underrated thermostat may not activate every stage your system has.
Do I need a C-wire for a smart thermostat?
Most Wi-Fi and smart thermostats need a C-wire (common wire) for continuous 24V power to run the display, Wi-Fi radio, and app connectivity, and many models won't function reliably without one even if they technically power on with battery backup. If your system doesn't have a C-wire already run, some smart thermostats include a power extender kit that can add one without running new wire, though this depends on the specific HVAC system's wiring. A licensed HVAC technician can confirm whether your system supports one of these workarounds or needs a new wire run.
What's the difference between a heat pump thermostat and a conventional thermostat?
A heat pump thermostat is built to manage a reversing valve and often includes backup electric heat stages, which conventional gas or electric system thermostats don't need to control. Many thermostats support both system types, but the stage rating and wiring terminals differ, so always confirm compatibility with your specific system type before ordering.
Can I use a Wi-Fi thermostat with a zoned system?
Some Wi-Fi thermostats are designed to work with zoning panels and zone dampers, while others are built for single-zone control only. Check the thermostat's specifications for zoning compatibility, or use a dedicated zone control system alongside individual thermostats for each zone.
What voltage do most residential thermostats use?
Most residential thermostats operate on low-voltage 24V control circuits. Line voltage thermostats, used mainly for electric baseboard heat and fan coil units, switch 120V or 240V directly and require different wiring.
Can I install a thermostat myself?
Replacing a low-voltage 24V thermostat with a compatible model is within reach for many homeowners, since it typically involves labeled wire terminals. Line voltage thermostat installation involves higher voltage wiring and is best handled by a licensed electrician or HVAC technician.
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