Different target temperatures on grouped TRVs – expected behavior or bug?

[BoBBer446]

Hi,

I am using Better Thermostat in Home Assistant with multiple TRVs (TP-Link KE100) grouped into a single Better Thermostat entity for one room.

Setup:

• 2x TRVs (KE100) in the same room
• 1x external temperature sensor
• Calibration: Hybrid
• Mode: AI Time Based
• target_temp_step: 1.0
• tolerance: 0.2

Expected behavior:
Both TRVs should contribute to reaching the room target temperature.

Observed behavior:

• One TRV is set to ~26°C
• The other TRV is set to 17°C

BT is set to e.g. 27°C

This results in only one radiator heating while the other stays near closed.

Questions:

1. Is it expected that grouped TRVs receive different target temperatures?
2. Under what conditions would one TRV be set to 5°C while another is actively heating?
3. Is this intended load balancing behavior or a sign that one TRV is considered invalid/unavailable?
4. Should both TRVs normally stay within a similar temperature range (e.g. ±1–2°C)?

Additional context:

• External temperature sensor is working correctly
• Both TRVs are reachable and respond to manual commands
• Issue only appears when controlled via Better Thermostat

Any clarification on how Better Thermostat distributes heat demand across multiple TRVs would be very helpful.

Thanks!

[cl445]

Two things to address here:

1. "Hybrid" calibration: that mode was removed from BT a while back (replaced by the new Direct Valve Based calibration type, see commit b30f874). If your config still shows "Hybrid", you're on an older release — please update to 1.8.0-Beta-17 via HACS (enable "Show beta versions" in the BT entry).

2. Different displayed targets on grouped TRVs: with offset-based calibration this is expected behavior, not a bug. BT sends a base target to each TRV, then applies a per-TRV calibration offset based on the difference between the external sensor and each TRV's own local sensor. Since the two KE100s sit in different positions in the room, they read slightly different temperatures, so they get different offsets and end up displaying different targets on the device.

For more uniform displayed targets on the TRVs themselves, use Target Temp Based calibration type. KE100 reports valve position, so Direct Valve Based may also work (worth trying once you're on the beta).