24VAC Thermostats for North American Systems
Also called a 24 volt thermostat - these four models run on the standard North American 24VAC control circuit. All of them control 2H/2C conventional and 4H/2C heat pump systems, support dual fuel, and work with the SWB511 C-Wire Adapter when the wall has no C wire.
Four models, one wiring standard
They share the same 24VAC terminals and the same heat pump support. What separates them is how many remote sensors they accept, whether they can drive humidity equipment, and what the front panel looks like.
PCT513
Best when several rooms run hot or cold
Up to 16 remote sensors, 4.3-inch touchscreen, PIR occupancy built in.
- 16 sensors
- 4.3" 480x272
- PIR 3 m / 70°
- 10 terminals
PCT5231-W-TY
Best for a standard 24VAC system with dual fuel
LED segment display keeps cost down; 9 sensors, radar option, fits 83.3 mm junction boxes.
- 9 sensors
- LED segment
- Radar optional
- 83.3 mm box
PCT533-W-TY
Best when you need humidity control
The only model with HUM/DEHUM outputs (ACC1/ACC2), plus 480x800 screen and radar occupancy.
- 6 sensors
- 4.3" 480x800
- Radar standard
- ACC1/ACC2
PCT533C-W-TY
Best when no sensors or humidity control are needed
Same 4.3-inch platform as the 533, without remote sensors, humidity outputs or occupancy sensing.
- No sensors
- 4.3" 480x800
- No humidity
- TF card
What actually differs
Four rows are identical across the range. The rows below them are what decide an installation.
| Specification | PCT513 | PCT5231 | PCT533 | PCT533C |
|---|---|---|---|---|
| Conventional | 2H/2C | 2H/2C | 2H/2C | 2H/2C |
| Heat pump | 4H/2C | 4H/2C | 4H/2C | 4H/2C |
| Dual fuel | Yes | Yes | Yes | Yes |
| Display | 4.3" touch | LED segment | 4.3" touch | 4.3" touch |
| Remote sensors | 16 | 9 | 6 | 0 |
| Occupancy | PIR 3 m | Radar (opt.) | Radar | - |
| Humidifier / dehumidifier | - | - | ACC1/ACC2 | - |
| Wiring terminals | 10 (S) | 10 (CWA) | 12 (CWA+ACC) | 10 (CWA) |
A dash means that model does not have the feature. Full 20-row comparison in the technical comparison article.
If your wall has no C wire
All four models can still be installed. The SWB511 C-Wire Adapter powers the thermostat from the existing Y/Y1, G and R (or Rc or Rh) wires, so nothing new has to be pulled through the wall.
If a W wire is also present, connect it as well - the adapter keeps your second heating stage.
What these thermostats do not support
- • 2-wire systems
- • Fan coil units
- • Multi-speed fans
- • ERV / HRV / VRV systems
- • Baseboard heaters
- • 3-stage conventional heating
- • Systems at 120V or higher
- • Thick wires with wire nuts
Looking for other thermostats?
This page covers the current 24VAC Wi-Fi line for the US and Canada. ZigBee 24VAC models and 230V European models are listed in the catalogue.
See all thermostat families →Common questions
What is a 24VAC thermostat?
A 24VAC thermostat is powered and controlled by a low-voltage 24 volt AC circuit, the standard control voltage in North American heating and cooling equipment. All four models on this page run on 24VAC and need either a C wire or the SWB511 C-Wire Adapter for power.
Do these work with heat pumps and dual fuel systems?
Yes. All four support 2H/2C conventional systems and 4H/2C heat pump systems, including auxiliary or emergency heat and dual fuel switching between a heat pump and a gas furnace.
Which model can control a humidifier or dehumidifier?
Only the PCT533-W-TY. It has dedicated ACC1 and ACC2 terminals and supports 1-wire or 2-wire humidifier and dehumidifier wiring. The other three models have no HUM or DEHUM output.
Are 230V European models on this page?
No. This page covers the current 24VAC Wi-Fi line for the US and Canada. ZigBee 24VAC models and 230V European models are listed in the full catalogue.
Not sure which model fits?
Run the wiring check, or send us a photo of your old thermostat base. We will confirm the model and whether the adapter is needed.