Thermostat Card is higher than maximum available layout height

[HenryLoenwind]

Checklist

• I have updated to the latest available Home Assistant version.
• I have cleared the cache of my browser.
• I have tried a different browser to see if it is related to my browser.
• I have tried reproducing the issue in safe mode to rule out problems with unsupported custom resources.

Describe the issue you are experiencing

The Thermostat Card, with all four features enabled, is 9 grid units high. The card layout offers a maximum of 8 grid units.

The card will shrink to 8 units, leaving out parts of its functionality (the "+" and "-" buttons). Manually changing the layout to 9 units of height in the yaml works.

Describe the behavior you expected

The layout GUI offering as much space as any standard card needs.

Steps to reproduce the issue

1. Add a Thermostat Card and enable all 4 features.

What version of Home Assistant Core has the issue?

2025.4.2

What was the last working version of Home Assistant Core?

No response

In which browser are you experiencing the issue?

Version 136.0.7103.25 (Official Build) beta (64-bit)

Which operating system are you using to run this browser?

Windows 10

State of relevant entities

Problem-relevant frontend configuration

Javascript errors shown in your browser console/inspector

Additional information

No response

[HenryLoenwind]

PS: In case it wasn't quite clear, the issue is that the assumption that "12x8" is the maximum the card layout GUI needs to offer is wrong because there is at least one standard card that needs "12x9". There may be other cards that can get too high to fit into those 8 units; I didn't go looking. There's nothing wrong with the Thermostat Card. It even reacts sensibly to being restricted beyond what it actually needs.

[heathnate]

Hello, would this be a good first issue for me to contribute to? I am hoping to contribute to Home Assistant for a class project.

[karwosts]

Hello, would this be a good first issue for me to contribute to? I am hoping to contribute to Home Assistant for a class project.

I think that could be a reasonably simple thing to look into for a new contributor. I would look at why the max_rows evaluates to what it does, see if that equation needs an update.

[heathnate]

I have been trying to configure my dev environment for working on this issue. This is the path I have taken so far: Create Thermostat Card -> Create climate entity (using MQTT) -> Configure add-on for Mosquito broker for MQTT entity -> Run HA Operating System (instead of Core) -> Clone HA OS repo. At the point of trying to clone the HA OS repo I am running into "file path too long" issues. Is this common? How do I work around this? I have seen some tips on Stack Overflow but nothing has seemed to work.

[karwosts]

I would recommend the Discord server if you want development help. But just a few minor points:

• you don't need MQTT, if you just need a climate entity there are several in the demo: integration.
• you don't need to mess with HA OS, would just recommend trying the frontend devcontainer, it should have everything encapsulated that you need.