diff --git a/README.md b/README.md
index 8d896b9..cf6ca9f 100644
--- a/README.md
+++ b/README.md
@@ -145,6 +145,33 @@ Each appliance is exposed as a `climate` entity with:
 
 Schedule editing beyond setpoint rewrites is still limited by the cloud API.
 
+## Upgrading to 3.0.0
+
+This is a **major** release relative to 2.0.0. After updating via HACS, **restart Home Assistant**.
+
+### Requirements
+
+- Home Assistant (current supported version for this integration)
+- [`dimplex-controller>=0.8.0`](https://pypi.org/project/dimplex-controller/) (installed automatically from the integration requirements)
+
+### Breaking / behavioural changes
+
+- **Climate entities** are created per appliance. Prefer climate for setpoints and boost/away/eco presets.
+- **Energy** is no longer a single mislabelled “30-day” total:
+  - **Energy lifetime** — cumulative cloud daily history
+  - **Energy today** — local calendar day from midnight
+    Prefer **Energy today** for the Energy Dashboard when you want daily usage without a large historical pop-in on first add.
+- **Entity unique IDs / names** may change (for example EcoStart now has a stable `_ecostart` suffix; open-window detection is a switch as well as a binary sensor). You may see renamed entities or need to clean orphans once.
+- **Polling** is split: status on a short interval, energy on a longer interval (configurable in options).
+- **Diagnostics** (error/warning/last telem, rated power, charge capacity, energy T2 today) exist but may be **disabled by default** — enable in the entity registry if you need them.
+
+### After upgrade checklist
+
+1. Confirm Dimplex Hub config entry is **loaded** (no import / requirement errors in logs).
+2. Review new `climate.*` entities and energy sensors.
+3. Re-point automations that used old entity IDs.
+4. For Energy Dashboard, use **Energy today** (or statistics) rather than dumping multi-year **lifetime** into the dashboard unless you intend that.
+
 ## Known limitations
 
 - Full weekly schedule UI is not exposed yet (setpoint writes update timer periods).
diff --git a/custom_components/dimplex/manifest.json b/custom_components/dimplex/manifest.json
index 6344369..712972a 100644
--- a/custom_components/dimplex/manifest.json
+++ b/custom_components/dimplex/manifest.json
@@ -7,6 +7,6 @@
   "documentation": "https://github.com/kroperuk/dimplex-controller-hass",
   "iot_class": "cloud_polling",
   "issue_tracker": "https://github.com/kroperuk/dimplex-controller-hass/issues",
-  "requirements": ["dimplex-controller>=0.7.0"],
+  "requirements": ["dimplex-controller>=0.8.0"],
   "version": "2.0.0"
 }
diff --git a/docs/advanced.md b/docs/advanced.md
index 63b0c47..a8a523b 100644
--- a/docs/advanced.md
+++ b/docs/advanced.md
@@ -90,7 +90,7 @@ action:
 
 ### PyPI dependency
 
-Requires [`dimplex-controller>=0.7.0`](https://pypi.org/project/dimplex-controller/). Bump `custom_components/dimplex/manifest.json` when adopting a new library floor.
+Requires [`dimplex-controller>=0.8.0`](https://pypi.org/project/dimplex-controller/). Bump `custom_components/dimplex/manifest.json` when adopting a new library floor.
 
 ### Local development
 
diff --git a/requirements_dev.txt b/requirements_dev.txt
index dee38b9..1ad71ed 100644
--- a/requirements_dev.txt
+++ b/requirements_dev.txt
@@ -1,2 +1,2 @@
 homeassistant
-dimplex-controller>=0.7.0
+dimplex-controller>=0.8.0