MELCloud Home: HTTP 500 from energy telemetry makes all devices/entities unavailable

[meevil]

The problem

Note

I investigated this issue with the help of AI (ChatGPT), including enabling debug logging and analyzing the resulting Home Assistant logs and stack trace.

I am therefore not a developer of the MELCloud Home integration and some of my technical conclusions below are based on this AI-assisted analysis. I have included the actual error messages and relevant information so that the maintainers can verify the conclusions.

The problem

I have three Mitsubishi Electric air conditioners connected through the official Home Assistant MELCloud Home integration:

• 1 × Mitsubishi Electric MSZ-AY35
• 2 × Mitsubishi Electric MSZ-AY25
• All units use Mitsubishi WiFi modules
• All three devices use the same MELCloud Home account

Intermittently, all three devices and all 45 entities become unavailable at exactly the same time in Home Assistant.

However, while Home Assistant reports them as unavailable, all three air conditioners remain online and controllable through the official MELCloud Home Android app.

After enabling debug logging for:

logger:
default: info
logs:
homeassistant.components.melcloud_home: debug
aiomelcloudhome: debug

I was able to capture the error.

Actual error

The failure occurs while retrieving energy telemetry:

aiohttp.client_exceptions.ClientResponseError:
500, message='Internal Server Error',
url='https://mobile.bff.melcloudhome.com/telemetry/telemetry/energy/...'

The requested endpoint is the energy telemetry endpoint, approximately:

/telemetry/telemetry/energy/{deviceId}
?from=2026-08-01T00:00
&to=2026-08-14T20:33
&interval=Hour
&measure=cumulative_energy_consumed_since_last_upload

The exception then propagates through "get_energy_telemetry()":

aiomelcloudhome.exceptions.MelCloudHomeConnectionError:
Connection error: 500, message='Internal Server Error'

and subsequently causes the Home Assistant coordinator update to fail:

homeassistant.helpers.update_coordinator.UpdateFailed:
Error communicating with MELCloud Home API

The coordinator reports:

Finished fetching melcloud_home data in 5.885 seconds (success: False)

After this failed update, all three MELCloud Home devices/entities become unavailable in Home Assistant.

Expected behavior

A failure of the optional energy telemetry endpoint should probably not cause the complete MELCloud Home coordinator update to fail.

If the main device/context data can still be retrieved successfully, climate control and the other entities should remain available.

Ideally:

Device/context request succeeds
↓
Climate entities remain available

Energy telemetry request fails with HTTP 500
↓
Energy sensor becomes unavailable/unknown
↓
Error is logged

Instead, the current behavior appears to be:

Device/context request succeeds
↓
Energy telemetry request returns HTTP 500
↓
Coordinator update fails
↓
ALL MELCloud Home devices/entities become unavailable

This is particularly noticeable with multiple air conditioners because one failed energy telemetry request appears to affect the complete MELCloud Home account/coordinator.

Additional observation

Successful coordinator updates also retrieve energy telemetry from the Mitsubishi API. For example, debug logging shows responses containing:

cumulativeEnergyConsumedSinceLastUpload

So the energy endpoint does work most of the time, but occasionally returns HTTP 500.

Interestingly, the official MELCloud Home Android app does not show energy consumption data for my units, although the API apparently provides telemetry data.

Home Assistant version

• Core: 2026.8.1
• Installation method: Home Assistant OS
• Supervisor: 2026.07.5
• Operating System: 18.2
• Frontend: 20260729.6

Integration

MELCloud Home

Devices

• Mitsubishi Electric MSZ-AY35
• Mitsubishi Electric MSZ-AY25
• Mitsubishi Electric MSZ-AY25

Network

Home Assistant itself still had working LAN and Internet connectivity when investigated.

Tests from the Home Assistant host showed:

192.168.1.1 → reachable, 0% packet loss
8.8.8.8 → reachable, 0% packet loss

DNS resolution of the MELCloud API host also worked.

The HTTP 500 response therefore appears to originate from the MELCloud Home API rather than from a DNS failure.

Possible improvement

Would it be possible to handle "get_energy_telemetry()" failures independently from the main coordinator update?

For example, catching "MelCloudHomeConnectionError" for individual energy telemetry requests and continuing the coordinator update could prevent an optional telemetry failure from making otherwise functional climate devices unavailable.

I can provide additional debug logs or test a potential fix if needed.

What version of Home Assistant Core has the issue?

core-2026.8.1

What was the last working version of Home Assistant Core?

No response

What type of installation are you running?

Home Assistant OS

Integration causing the issue

Melcloud Home

Link to integration documentation on our website

https://www.home-assistant.io/integrations/melcloud/

Diagnostics information

No response

Example YAML snippet

Anything in the logs that might be useful for us?

2026-08-14 22:33:37.868 ERROR (MainThread) [homeassistant.components.melcloud_home.coordinator]
Error fetching melcloud_home data: Error communicating with MELCloud Home API

aiohttp.client_exceptions.ClientResponseError: 500, message='Internal Server Error',
url='https://mobile.bff.melcloudhome.com/telemetry/telemetry/energy/[device-id]?from=2026-08-01T00:00&to=2026-08-14T20:33&interval=Hour&measure=cumulative_energy_consumed_since_last_upload'

aiomelcloudhome.exceptions.MelCloudHomeConnectionError:
Connection error: 500, message='Internal Server Error'

homeassistant.helpers.update_coordinator.UpdateFailed:
Error communicating with MELCloud Home API

2026-08-14 22:33:37.870 DEBUG (MainThread)
[homeassistant.components.melcloud_home.coordinator]
Finished fetching melcloud_home data in 5.885 seconds (success: False)

Additional information

I investigated this issue with the help of ChatGPT. The AI helped me enable debug logging and analyze the resulting stack trace, so my technical interpretation of the cause may not be completely correct.

The issue occurs very frequently. During testing, the MELCloud Home entities switched between available and unavailable multiple times within approximately 20 minutes.

The official MELCloud Home Android app remained functional while the devices were unavailable in Home Assistant.

The debug log appears to show that an HTTP 500 response from the energy telemetry endpoint causes the complete coordinator update to fail. As a result, all three air conditioners and their entities become unavailable, even though the actual climate devices remain reachable through MELCloud Home.

[home-assistant]

Hey there @erwindouna, mind taking a look at this issue as it has been labeled with an integration (melcloud) you are listed as a code owner for? Thanks!

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@meevil Thanks for reporting this issue!

Before we dive in, please make sure this isn't a duplicate by searching through existing issues. Also check recently closed issues, as your problem might already be fixed but not yet released.

https://github.com/home-assistant/core/issues?q=%20label%3A%22integration%3A%20melcloud%22%20
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melcloud documentation
melcloud source
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[meevil]

One additional observation from the debug log may be relevant:

For all three Mitsubishi units, the "/context" response reports:

hasEnergyConsumedMeter: true
isEnergyUsageCompatible: false

Despite "isEnergyUsageCompatible: false", Home Assistant still requests energy telemetry for all three devices.

The official MELCloud Home Android app does not display energy consumption data for these units.

However, the telemetry endpoint does return energy data in successful requests. For example, Home Assistant receives "cumulativeEnergyConsumedSinceLastUpload" values. A successful update consists of "/context" followed by energy telemetry requests for all three units and takes around 6–8 seconds.

This makes me wonder whether "isEnergyUsageCompatible: false" should also be considered before requesting energy telemetry, or whether this combination of capability flags is expected.

Importantly, "/context" itself reports all three units as:

isConnected: true
isInError: false

even around the periods where Home Assistant intermittently marks all MELCloud Home entities unavailable.

So the devices themselves appear to remain connected; the observed failure seems related to the subsequent API/telemetry processing.

[erwindouna]

Try again on version 2026.8.2, I think we got it resolved with a patch. Let me know if that also works for you. :)