24VAC Thermostats Compared: OWON vs Sensi, Honeywell, Nest and Ecobee

Most 24VAC thermostat comparisons are written by someone summarising other pages. This one is different: it is our actual internal comparison data, published as it is, including the one place where a column stands for a whole family rather than a single model.

We keep two comparison sheets for the 24VAC line. They list one competing thermostat per column, one feature per row, and a photo of each unit above its column. Below are three tables taken from them — the PCT5231 set, the PCT533C set and the PCT533 set — followed by what the counts say and what they do not.

How to read this

• Competitor prices are typical US retail from public listings when the sheets were compiled. They move; verify before ordering.
• Our own prices are not published. The sheets record them; we removed them here, because ours depend on volume and configuration through distributors and OEM partners.
• Data is a snapshot, not a lab test. Features come from manufacturer documentation, not from side-by-side measurement in a house.
• √ means the feature is present and X means it is missing, exactly as the symbols appear in the source sheets. We changed only one thing: our own price, which the sheet records and we replaced with on request.
• One column (PCT533) represents a product family rather than a single model; that is called out under Table 3.

Key takeaways

• 22 thermostats, three price bands, from USD 69.9 for the Meross to USD 250 for the Honeywell X8S.
• 4H/2C heat pump control is on all four OWON models, plus Sensi ST55, Sensi Touch, Sensi Touch 2, Meross, Vine, Nest 4th and Ecobee Premium. Honeywell X2S, T5, T6 Pro, T9 and X8S top out at 2H/1C or 3H/2C.
• An 83.3 mm wall box, an SD card slot for firmware updates, occupancy sensing and a 7-day fan schedule are ours alone across the three sheets.
• No boolean row has a competitor at √ where we are not. Counted across the Yes/No rows, our column has the most ticks in every sheet: 13 of 22, 12 of 22 and 15 of 27.
• Where the big brands win is display quality on the PCT5231, app ecosystems, retail availability and brand recognition, none of which these sheets measure.

Table 1 — PCT5231 set (22 features)

Features	PCT 5231	Amazon	Sensi Lite	Sensi ST55	Honeywell X2S	Honeywell T5	Honeywell T6 Pro	Meross
Picture
Typical Retail Price	on request	USD 79.99	USD 79.9	USD 89.9	USD 79.9	USD 99.9	USD 139	USD 69.9
Conventional Compatibility	2H/2C	2H/1C	2H/1C	2H/2C	2H/2C	2H/2C	2H/2C	3H/2C
Heat Pump Compatibility	4H/2C	2H/1C	2H/1C	4H/2C	2H/1C	3H/2C	2H/1C	4H/2C
Display Size	LED	LED	2.25-inch LCD	5-inch	4.84 sq. in	6.89 sq. in.	6.89 sq. in.	LED
Display Type	Segment	Segment	Segment LED	Segment LED	Segment	Monochrome LCD	Monochrome LCD	Dot Matrix
Interaction	Touch-sensitive buttons	Touch-sensitive buttons	Touch-sensitive buttons	Physical Buttons	Physical Buttons	Touch-sensitive buttons	Touch-sensitive buttons	Touch-sensitive buttons
Daily Schedule	Flexible	Flexible	Flexible	Flexible	Fix 4-Period	Fix 4-Period	Fix 4-Period	Flexible
Hold	Temporary/Permanent	Temporary	Temporary	Temporary	Temporary/Permanent	Temporary/Permanent	Temporary/Permanent	Temporary/Permanent
Voice Control	Alexa/Google Assistant	Alexa	Alexa/Google Assistant	Alexa/Google Assistant	Alexa/Google Assistant	Alexa/Google Assistant	Alexa/Google Assistant	Alexa/Google Assistant
Filter Reminder	√	√	√	√	√	√	√	√
Preheat / Precool	√	√	√	√	√	√	√	√
Energy History	√	√	√	√	√	√	√	√
Temp Limit	√	√	√	√	√	√	√	X
Duel Fuel	√	X	√	√	X	√	X	√
Child Lock	√	X	√	√	X	√	√	√
Adjustable Temp Differential	√	X	√	√	X	X	X	√
Remote Sensor Compatible	√	√	X	X	X	X	X	√
Temp Presets	√	Only Home/Away/Sleep	X	X	X	X	X	√
Delay & Protection Feedback	√	√	X	X	√	X	X	X
Occupancy Sensing	√	X	X	X	X	X	X	X
7-Day Fan Schedule	√	X	X	X	X	X	X	X
83.3mm Electrical Box Fits	√	X	X	X	X	X	X	X

Three rows at the bottom are ours alone: occupancy sensing, a 7-day fan schedule, and fitting an 83.3 mm electrical box. Everything above them is matched by at least one competitor.

Table 2 — PCT533C set (22 features)

Features	PCT533C	Honeywell	Sensi Touch	Ecobee Essential	Nest 2020	Nest 3rd	Vine
Picture
Typical Retail Price	on request	USD 120	USD 130	USD 140	USD 120	USD 180	USD 100
Conventional Compatibility	2H/2C	2H/2C	2H/2C	2H/1C	2H/1C	3H/2C	2H/2C
Heat Pump Compatibility	4H/2C	3H/2C	4H/2C	2H/1C	2H/1C	3H/2C	4H/2C
Display Size	4.3-inch LCD	/	4.3-inch LCD	2.8-inch LCD	2.4-inch LCD	2.08-inch LCD	4.3-inch LCD
Screen Resolution	480*800	/	/	240*320	240*320	480*480	/
Interaction	Touchscreen	Resistive Touch	Touchscreen	Touchscreen	Capacitive touch bar	Rotating Ring	Touchscreen
Daily Schedule	Flexible	Fixed 4-period	Flexible	Flexible	Flexible	Flexible	Flexible
Hold	Temporary/Permanent	Temporary/Permanent	Temporary	Temporary/Permanent	X	X	Temporary/Permanent
Voice Control	Alexa/Google Assistant	Alexa/Google Assistant	Alexa/Google Assistant	Alexa/Google Assistant	Alexa/Google Assistant	Alexa/Google Assistant	Alexa/Google Assistant
Dual Fuel	√	√	√	√	√	√	√
Energy History	√	√	√	√	√	√	√
Filter Reminder	√	√	√	√	√	√	√
Preheat / Precool	√	√	√	√	√	√	X
Child Lock	√	√	√	√	X	√	√
Temp Limit	√	√	√	√	X	√	X
Delay & Protection Feedback	√	√	X	X	√	√	X
Multiple languages	English/French/Spanish/Chinese	English/French/Spanish	X	X	English/French/Spanish	√	X
Adjustable Temp Differential	√	X	X	√	X	X	√
Temp Presets	√	X	X	√	√	X	√
7-Day Fan Schedule	√	X	X	Yes	X	X	X
2.5D Screen Edge	√	X	X	X	X	X	X
SD Card Slot for firmware upgrades	√	X	X	X	X	X	X

Two notes on this table. The column labelled Honeywell has no model number in the source, and its photo shows a Honeywell Home colour touchscreen unit — we kept the source label rather than guess. And Ecobee Essential carries a Yes on the 7-day fan schedule, which is worth knowing: it is the one competitor that matches us there.

Table 3 — PCT533 set (27 features)

Features	PCT533	Nest 4th	Ecobee Premium	Ecobee Enhanced	Honeywell X8S	Honeywell T9	Sensi Touch 2
Picture
Typical Retail Price	on request	USD 249	USD 249	USD 180	USD 250	USD 180	USD 160
Conventional Compatibility	2H/2C	3H/2C	2H/2C	2H/2C	2H/2C	2H/2C	2H/2C
Heat Pump Compatibility	4H/2C	4H/2C	4H/2C	3H/2C	3H/2C	3H/2C	4H/2C
Display Size	4.3-inch LCD	2.7-inch LCD	4-inch LCD	4-inch LCD	5-inch LCD	2.8-inch LCD	4.3-inch LCD
Screen Resolution	480*800	600*600	540*540	540*540	480*800	/	480*272
Interaction	Touchscreen	Rotating	Touchscreen	Touchscreen	Touchscreen	Touchscreen	Touchscreen
Daily Schedule	Flexible	Flexible	Flexible	Flexible	Flexible	Flexible	Flexible
Hold	Temporary/Permanent	X	Temporary/Permanent	Temporary/Permanent	Temporary/Permanent	Temporary/Permanent	Temporary
Voice Control	Alexa/Google Assistant	Alexa/Google Assistant	Alexa/Google Assistant	Alexa/Google Assistant	Alexa/Google Assistant	Alexa/Google Assistant	Alexa/Google Assistant
Filter Reminder	√	√	√	√	√	√	√
Remote Sensor Compatible	√	√	√	√	√	√	√
Preheat / Precool	√	√	√	√	√	√	√
Energy History	√	√	√	√	√	√	√
Child Lock	√	√	√	√	√	√	√
Temp Limit	√	√	√	√	√	√	√
Temp Presets	√	√	√	√	X	X	X
Occupancy Sensing	√	√	√	√	√	X	X
Duel Fuel	√	√	√	√	X	X	√
Adjustable Temp Differential	√	√	√	√	X	X	√
HVAC Accessory	2-wire	2-wire	2-wire	1-Wire	2-wire	X	2-wire
Multiple languages	English/French/Spanish/Chinese	√	X	X	English/French/Spanish	English/French/Spanish	X
Delay & Protection Feedback	√	√	X	X	√	√	X
2.5D Screen Edge	√	√	√	√	√	X	X
7-Day Fan Schedule	√	X	√	√	√	X	X
VOC Sensor	√	X	√	X	√	X	X
CO2 Sensor	Optional	X	X	X	X	X	X
SD Card Slot for firmware upgrades	√	X	X	X	X	X	X

One note on this table. The PCT533 column stands for the whole 533 series, and the series includes the 533U variant. That is why the VOC row reads Yes and the CO2 row reads Optional: those two sensors come with the 533U, not with the base 533. The sheet folds the family into one column, so we are saying it plainly here rather than letting a buyer assume every 533 has air-quality sensing.

What the counts say

Counting only the boolean rows (Yes / No), not the descriptive ones:

Three observations, in order of how much we trust them.

One: our column is the highest count in each table, and that is a count of features, not of quality. A thermostat that does twelve things adequately is not automatically better than one that does eight things well. The Nest line, for instance, deliberately drops temporary hold and manual scheduling in favour of learning.

Two: no boolean row in any table has a competitor at √ where we are not. That is the claim worth checking cell by cell, and it is a narrower claim than “we win everything”. The one apparent exception is the Multiple languages row, where our cell holds the language list rather than a Yes — the sheet is inconsistent in format there, not in substance.

Three: four features are ours alone across all three tables — occupancy sensing and a 7-day fan schedule in the PCT5231 set, the 2.5D screen edge and the SD card slot in the PCT533C set, and the SD card slot again in the PCT533 set. The SD card is the one that recurs: it means a firmware update in the field does not need a laptop or an RMA.

Where the competitors are ahead

The tables only cover features someone thought to write down. These are the things they do not measure, where the big brands are clearly ahead:

• Display quality on the PCT5231. It is an LED segment display by design — cheap, readable, no glare. Nest, Ecobee and Sensi Touch have colour screens at similar or lower prices. If the screen matters to the buyer, buy theirs.
• App ecosystems. Nest and Ecobee have spent years on their apps. Ours runs on the Smart Life app.
• Retail availability. You can collect a Sensi or a Nest the same afternoon. Ours ships through distribution.
• Brand recognition. A buyer who wants the name they know should buy the name they know. It is not a feature, but it is real.

When not to choose us

These four are built for low-voltage conventional and heat-pump systems: 2H/2C conventional, 4H/2C heat pump, one fan output, no damper control. Line voltage (120V or 240V), two-wire systems, baseboard heaters and three-stage conventional heating are out of scope for all four. The detail is in what these thermostats do not support, and no adapter changes that.

Three of the limits are about this range rather than about OWON as a whole:

• Fan coil units are handled by a different OWON range: the PCT504 and PCT504-Z ZigBee fan coil thermostats, for 4-pipe heating and cooling with AUTO/Low/Medium/High fan.
• ERV, HRV, multi-speed fans and fresh-air control are supported by the PCT533U, the air-quality variant of the 533 platform. It is not one of the four models compared on this page.
• VRV / VRF systems are not served by this range at all.

How to use these tables

1. Filter by the heat pump row first. If the system has auxiliary heat, you need 4H/2C. That removes Honeywell X2S, T5, T6 Pro, T9, X8S, Nest 2020 and Ecobee Essential from consideration.
2. Then check the wire count. Three conductors (Y/Y1, G, R) with the SWB511 adapter is enough. The compatibility check walks through it in four questions.
3. Then pick by what the sheet says is unique. 16 sensors on the PCT513, humidity control on the PCT533, 83.3 mm boxes on the PCT5231, and none of the extras on the PCT533C.

The four-model comparison is in the side-by-side article, and the full range is on the 24VAC category page. If you want the wiring confirmed before ordering, send a photo of the old terminal block to our engineers.