Back in January, I wrote about finding the perfect Zigbee TRV for Home Assistant. The MOES TRV801 had everything I wanted: beautiful LED display, quiet operation, great battery life, and most importantly, it worked perfectly with Better Thermostat integration.

So when I needed more thermostats, I ordered from the same seller, same product listing. Same results, right?

The Chinese Firmware Lottery

Anyone who's been buying Zigbee devices from AliExpress knows this feeling. Same product photos, same listing, completely different firmware inside.

When the new batch arrived, the pairing process was already different. You need to scroll left with the minus button until "OFF" appears, then hold SET for 5 seconds. Not what the manual says, but I've dealt with worse.

The real problem? No hand icon ☝ on the display. That icon indicates Manual mode, and without it, Better Thermostat loses its grip on the valve.

TRV801_1 vs TRV801Z: The Missing Mode

Here's the original thermostat (TRV801_1) in Zigbee2MQTT:

Preset options: auto, manual, off, on

And here's what I received (TRV801Z):

Preset options: off, antifrost, eco, comfort, auto, on

No manual mode. The mode that tells the TRV to just execute whatever temperature it receives without thinking.

SONOFF ZBDongle-P - ZigBee Coordinator

The foundation of any ZigBee setup with Home Assistant. Without a solid coordinator, your TRVs are just expensive thermometers. Proven, stable, affordable.

Check ZBDongle-P

Device Identifiers

For those searching (you'll thank me later):

What Didn't Work

I tried replicating my working setup from the original article. Same Better Thermostat settings, same external temperature sensor, same logic.

The valve would slam to 100% or stay at 0%. The TRV was running its own show, following internal comfort/eco logic instead of listening to Home Assistant.

Preset combinations

Every option gave different problems:

• preset: comfort - TRV ignores BT, follows internal algorithm
• preset: auto - Follows internal weekly schedule
• preset: on - 100% open, always
• preset: off - Closed, always

Versatile Thermostat with Direct Valve Control

TRV801Z exposes a position entity showing valve opening percentage. I thought I could bypass the TRV's brain entirely using Versatile Thermostat with "Direct valve control".

Installed it, configured as "Over climate" with direct valve control, went to select the position entity and... nothing. The position entity is read-only. The TRV reports its valve state but doesn't accept commands.

From the Zigbee2MQTT docs:

"Position. Value can be found in the published state on the position property. It's not possible to read (/get) or write (/set) this value."

Dead end.

What Actually Works: Aggressive Calibration

After reading the Better Thermostat documentation more carefully, I found the answer. The Aggressive calibration mode doesn't try to gently correct the TRV. It lies to it.

The Configuration

In Zigbee2MQTT:

Preset: comfort
Hysteresis: comfort

The hysteresis: comfort setting enables smooth 0-100% valve control instead of binary on/off.

In Better Thermostat:

How Aggressive Mode Works

When Better Thermostat wants 21.5°C and the room is at 19°C, it doesn't send 21.5°C to the TRV. It sends 23°C, 24°C, even 25.5°C. The TRV thinks it needs to heat aggressively, opens the valve wide, and the room warms up faster.

As the room approaches the target, BT gradually reduces its "lie" until the temperatures converge.

SONOFF SNZB-02 - Temperature Sensor

TRV's built-in thermometer sits next to the radiator - it lies. This tiny sensor measures actual room temperature. Battery lasts a year. Essential for accurate automation.

Check SNZB-02

Test Results

I ran a heating cycle from 18.5°C to 21.5°C and logged everything to InfluxDB.

Temperature Progression

BT pushed the setpoint all the way to 25.5°C to reach a target of 21.5°C. Once the room hit 21.75°C, it dropped the setpoint to 21°C and the valve closed.

ZigBee Door/Window Sensor

Open window + radiator at max = money flying out (literally). Pair with Home Assistant to auto-stop heating when windows are open. Cheap insurance for your heating bill.

Check window sensor

The Oscillation Pattern

The valve didn't smoothly decrease from 100% to 0%. Instead, it oscillated between two states:

• ON mode (100%) - BT switches TRV to preset: on when it wants maximum heating
• COMFORT mode (62-78%) - BT switches to preset: comfort for proportional control

The logs show this clearly:

11:03:10 - state changed to "heating" triggered by Climate: Set HVAC mode
11:03:06 - state changed to "Auto" triggered by Climate: Set HVAC mode
10:58:51 - state changed to "heating" triggered by Climate: Set HVAC mode
10:51:46 - state changed to "Auto" triggered by Climate: Set HVAC mode

BT rapidly switches between modes to approximate the valve opening it wants. It's not elegant, but it works.

InfluxDB Query

For those who want to analyze their own data:

from(bucket: "home_assistant/autogen")
  |> range(start: -7h)
  |> filter(fn: (r) => 
    r["entity_id"] == "gabinet_temperature" or 
    r["entity_id"] == "gabinet_glowica_position"
  )
  |> filter(fn: (r) => r["_field"] == "value")
  |> map(fn: (r) => ({ r with _value: float(v: r._value) }))
  |> pivot(rowKey:["_time"], columnKey: ["entity_id"], valueColumn: "_value")
  |> sort(columns: ["_time"], desc: true)

Recommended Z2M Settings

Beyond the preset and hysteresis, I also adjusted:

• Comfort temperature: 22°C (close to my actual 21.5°C target)
• Eco temperature: 17°C (matches my BT night mode)

This gives BT more headroom to work with when using comfort mode.

Not a Downgrade, Just Different

Here's the thing: the Aggressive calibration approach isn't worse. It might even be faster.

Both thermostats reach the target temperature in roughly the same time. The difference is purely cosmetic - how it looks in Home Assistant logs and dashboards.

TRV801Z (New, Aggressive Mode) - Office

Temperature and setpoint:

Valve position:

The valve jumps between 0%, ~65%, and 100%. The setpoint line looks erratic. But the room heats up steadily.

TRV801_1 (Old, Manual Mode) - Living Room

Temperature and setpoint:

Valve position:

The valve moves smoothly between 0% and ~70%. The setpoint stays constant. The graph looks "cleaner".

Same Result

Both rooms reached their target temperatures. Both maintained them without overshooting. The old TRV looks prettier in charts, the new one looks like it's having a seizure. But they both heat the room.

Since these TRVs are nearly silent (no loud valve clicks), you won't notice the difference in daily use. The aggressive mode oscillations happen in the background. The room just gets warm.

What I Learned

Buying the "same" Chinese Zigbee device twice doesn't guarantee the same firmware. Check the manufacturerName in Z2M before assuming compatibility. The _TZE200_* variants have manual mode. The _TZE204_* variants might not.

When a TRV doesn't offer manual mode, Aggressive calibration in Better Thermostat compensates effectively. The valve oscillates, the presets switch rapidly, the setpoint looks insane in the logs. But the room reaches and maintains the target temperature just as well.

If you care about clean graphs, hunt for the old firmware. If you just want a warm room, Aggressive mode works fine.

Where to Buy

The MOES TRV:

MOES TRV ZigBee - Smart Radiator Valve

Smart thermostatic radiator valve with ZigBee connectivity. Works great with Home Assistant and Zigbee2MQTT, but watch out for firmware differences - same model, different behavior. Full breakdown in the article.

Check Price on AliExpress

You might receive TRV801_1 (with manual mode) or TRV801Z (without). Ask the seller about firmware version, or just configure Aggressive calibration and move on with your life.

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