· OWON Technology · Thermostats · 5 min read
PCT513 vs PCT5231 vs PCT533: Which 24VAC Thermostat Fits Your System
Four 24VAC thermostats share one wiring layout. Compare heat pump stages, remote sensor limits, humidity outputs and C-wire requirements before ordering.
If you have rooms that stay cold in winter, choose the PCT513 - it accepts up to 16 remote sensors. If you need to control a humidifier or dehumidifier, only the PCT533-W-TY has that output. If neither sensors nor humidity equipment is involved, the PCT533C-W-TY gives you the same 4.3-inch platform for less wiring. And if you need dual fuel with 9 remote sensors on a segment display, that is the PCT5231-W-TY.
All four run on 24VAC, control 2H/2C conventional and 4H/2C heat pump systems, and support dual fuel. The table below is the part that decides an installation.
Side-by-side specification comparison
| Specification | PCT513 | PCT5231-W-TY | PCT533-W-TY | PCT533C-W-TY |
|---|---|---|---|---|
| Conventional compatibility | 2H/2C | 2H/2C | 2H/2C | 2H/2C |
| Heat pump compatibility | 4H/2C | 4H/2C | 4H/2C | 4H/2C |
| Dual fuel / hybrid heat | Yes | Yes | Yes | Yes |
| Display | 4.3” colour touchscreen | LED segment, touch buttons | 4.3” colour touchscreen | 4.3” colour touchscreen |
| Screen resolution | 480 x 272 | - | 480 x 800 | 480 x 800 |
| Remote sensors (max) | 16 | 9 | 6 | None |
| Sensor must provide | PIR + temperature | Occupancy + temperature + humidity | Temperature + humidity | - |
| Occupancy sensing | PIR, 3 m / 70° | Radar (optional) | Radar (standard) | - |
| Humidifier / dehumidifier | - | - | 1-wire or 2-wire (ACC1/ACC2) | - |
| Scheduling periods per day | 4 | Up to 8 | Up to 8 | Up to 8 |
| Energy reports | - | Daily / weekly / monthly | Daily / weekly / monthly | Daily / weekly / monthly |
| Interface languages | English | English | EN / FR / ES / ZH | EN / FR / ES / ZH |
| TF card for logs and firmware | - | - | Yes (FAT32) | Yes (FAT32) |
| Fits 83.3 mm junction box | - | Yes | - | - |
| Wiring terminals | 10 (incl. S) | 10 (incl. CWA) | 12 (incl. CWA, ACC1, ACC2) | 10 (incl. CWA) |
| Temperature accuracy | ±1 °C | - | ±0.5 °C | ±0.5 °C |
| Humidity accuracy | ±3 % (20–80 %RH) | - | ±5 % | ±5 % |
| Dimensions (mm) | 131 x 78 x 29.2 | 97 x 97 x 21 | 143 x 82 x 21 | 143 x 82 x 21 |
| Tools included in the box | - | Phillips + flat-head screwdriver | Phillips + flat-head screwdriver | Phillips + flat-head screwdriver |
A dash means the datasheet for that model does not publish that figure. Every other value comes from the published datasheet or quick start guide for that model.
Heat pump capability is written 4H/2C because the thermostats control two compressor heating stages plus two auxiliary or emergency heating stages, and two cooling stages.
Remote sensors: 16, 9, 6 or none
A thermostat controls the whole house from one point, so its own reading is only the temperature of one room. Adding a remote sensor moves the reading to the room that matters, or averages several rooms.
The limit differs by model: 16 sensors on the PCT513, 9 on the PCT5231-W-TY, 6 on the PCT533-W-TY, and none on the PCT533C-W-TY.
Sensors do not remove the temperature difference between rooms. They decide which room the thermostat follows. If a bedroom never receives sun, a sensor in that bedroom makes the thermostat heat until the bedroom reaches target, instead of stopping when the hallway does.
The sensors themselves are not interchangeable across models. The PCT513 needs a sensor with PIR and temperature measurement. The PCT5231 expects occupancy, temperature and humidity. The PCT533 needs temperature and humidity only, with no occupancy channel.
Humidity control is a wiring difference, not a setting
Only the PCT533-W-TY has ACC1 and ACC2 terminals that drive a humidifier or dehumidifier, in 1-wire or 2-wire configuration. That is hardware, not a menu option - the other three models have no HUM or DEHUM terminal at all.
If your house has no humidity equipment, the PCT533C gives you the same screen and the same 4H/2C control without paying for terminals you will not use. The two models differ in exactly three things: remote sensors, humidity outputs and occupancy sensing.
C wire: three wires or four
All four thermostats need 24VAC power. Check the wires at your wall:
- With a C wire - connect it directly and you are done.
- Without a C wire, but with Y/Y1, G and R (or Rc or Rh) - you need the SWB511 C-Wire Adapter. On the thermostat side the adapter feeds R/RC/RH to RC, G to C and Y/Y1 to S, and its five white wires connect to the control board.
- Without a C wire and without those three wires - the system is not compatible.
If you also have W, connect it as well. The adapter keeps your second heating stage; it is optional but it is the difference between one-stage and two-stage heating.
Two conditions rule a system out before any of that: thick wires joined with wire nuts, and systems running at 120V or higher.
What none of these thermostats support
We publish this list because it is the fastest way to rule a system out:
- 2-wire systems
- Fan coil units
- Multi-speed fans
- ERV / HRV / VRV systems
- Baseboard heaters
- 3-stage conventional heating
- Systems running at 120V or higher
- Thick wires joined with wire nuts
If your system matches any line above, this range is not the right fit. We would rather you know before ordering.
How to choose in one minute
- Is there humidity equipment? Then you need the PCT533-W-TY. Stop here.
- Do you need sensors in more than a few rooms? The PCT513 covers up to 16.
- Is a junction box already in the wall, at 83.3 mm spacing? The PCT5231 backplate fits it without extra parts.
- None of the above? The PCT533C is the same platform as the 533, without the three features you are not using.
If you are not sure, send a photo of the old thermostat wiring. We will tell you which model works, whether the adapter is needed, and what to change at the control board.
Frequently Asked Questions
Which thermostat should I choose if some rooms stay cold?
Choose the PCT513. It accepts up to 16 remote sensors, so you can place one in each problem room. The thermostat then works from the average of the sensors that recently detected motion, or from one room you select.
Do all four models support heat pumps and dual fuel?
Yes. All four support 2H/2C conventional systems and 4H/2C heat pump systems, including auxiliary or emergency heat and dual fuel switching. The PCT501 in the same range is the only thermostat we make that does not support heat pumps.
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.
What is the difference between the PCT533 and the PCT533C?
They share the same 4.3-inch 480 by 800 display, the same 2H/2C and 4H/2C compatibility and the same TF card slot. The PCT533 adds up to 6 remote sensors, 1-wire or 2-wire humidity control and occupancy sensing. The PCT533C has none of those three.
Do I need a C wire?
The thermostat needs 24VAC power. With a C wire you connect it directly. Without one you need the C-Wire Adapter and at least three wires at the wall - Y/Y1, G and R (or Rc or Rh). If you also have W, the adapter keeps your second heating stage.
What systems are not supported?
These thermostats do not support 2-wire systems, fan coil units, multi-speed fans, ERV/HRV/VRV systems, baseboard heaters or 3-stage conventional heating. Systems running at 120V or higher, or with thick wires joined by wire nuts, are also not compatible.
