Thermostat: dry mode (SystemMode 0x08) not exposed as hvac_mode
Summary
ZHA does not expose HVACMode.DRY for Zigbee thermostats/HVAC devices that support SystemMode.Dry (0x08), even when the device explicitly advertises this capability.
Related
This is a companion issue to #226 and PR #708. That PR correctly fixes fan_only by detecting the presence of a Fan Control cluster (0x0202). The same gap exists for dry — it is a valid SystemMode value (0x08) with a corresponding HVACMode.DRY in Home Assistant, but it is never added to the hvac_modes list because controlSequenceOfOperation (per ZCL spec) only covers heating/cooling sequences and never includes dry mode.
Device context
I'm running a custom ESP32-C6 Zigbee bridge exposing a Midea split AC unit via standard clusters (Thermostat 0x0201, Fan Control 0x0202). The device supports SystemMode.Dry (0x08) as confirmed via direct ZCL attribute writes using zha.set_zigbee_cluster_attribute. The mode works correctly at the device level — ZHA simply never offers it as a valid choice.
The mappings HVAC_MODE_2_SYSTEM and SYSTEM_MODE_2_HVAC already handle DRY <-> Dry correctly, so the ZCL write path works. The only missing piece is adding HVACMode.DRY to the hvac_modes list.
Suggested fix
Similar to the fan_only approach in PR #708, HVACMode.DRY could be conditionally appended to hvac_modes when the device is known to support it — either via a capabilities attribute, a quirk flag, or by detecting SystemMode.Dry in the device's supported attribute values.
Expected behaviour
dry appears in the climate entity's hvac_modes list and is selectable from the HA UI for devices that support SystemMode.Dry.
Current behaviour
dry is absent from hvac_modes. Selecting it via climate.set_hvac_mode returns: "HVAC mode dry is not valid. Valid HVAC modes are: off, heat_cool, cool, heat."
Thermostat:
drymode (SystemMode 0x08) not exposed ashvac_modeSummary
ZHA does not expose
HVACMode.DRYfor Zigbee thermostats/HVAC devices that supportSystemMode.Dry (0x08), even when the device explicitly advertises this capability.Related
This is a companion issue to #226 and PR #708. That PR correctly fixes
fan_onlyby detecting the presence of a Fan Control cluster (0x0202). The same gap exists fordry— it is a validSystemModevalue (0x08) with a correspondingHVACMode.DRYin Home Assistant, but it is never added to thehvac_modeslist becausecontrolSequenceOfOperation(per ZCL spec) only covers heating/cooling sequences and never includes dry mode.Device context
I'm running a custom ESP32-C6 Zigbee bridge exposing a Midea split AC unit via standard clusters (Thermostat 0x0201, Fan Control 0x0202). The device supports
SystemMode.Dry (0x08)as confirmed via direct ZCL attribute writes usingzha.set_zigbee_cluster_attribute. The mode works correctly at the device level — ZHA simply never offers it as a valid choice.The mappings
HVAC_MODE_2_SYSTEMandSYSTEM_MODE_2_HVACalready handleDRY <-> Drycorrectly, so the ZCL write path works. The only missing piece is addingHVACMode.DRYto thehvac_modeslist.Suggested fix
Similar to the
fan_onlyapproach in PR #708,HVACMode.DRYcould be conditionally appended tohvac_modeswhen the device is known to support it — either via a capabilities attribute, a quirk flag, or by detectingSystemMode.Dryin the device's supported attribute values.Expected behaviour
dryappears in the climate entity'shvac_modeslist and is selectable from the HA UI for devices that supportSystemMode.Dry.Current behaviour
dryis absent fromhvac_modes. Selecting it viaclimate.set_hvac_modereturns: "HVAC mode dry is not valid. Valid HVAC modes are: off, heat_cool, cool, heat."