diff --git a/homelab-ai-bot/monitor.py b/homelab-ai-bot/monitor.py
index af3888787..bccbdc73e 100644
--- a/homelab-ai-bot/monitor.py
+++ b/homelab-ai-bot/monitor.py
@@ -24,6 +24,7 @@ ALERT_COOLDOWN_SECONDS = {
     "default": 3600,
     "error_rate": 1800,
     "hermes": 7200,
+    "heizung": 7200,
     "backup": 21600,
     "mirror_sync": 21600,
 }
@@ -102,6 +103,117 @@ def _is_host_suppressed(host: str, suppressed_hosts: set) -> bool:
     return False
 
 
+
+# Zigbee-Heizung CT152 (heizsteuerung) — erwartet online; Platzhalter ohne TRV weglassen
+HEIZ_API_BASES = [
+    os.environ.get("HEIZSTEUERUNG_API_BASE", "").rstrip("/"),
+    "http://100.105.175.123:8090",  # Tailscale CT152
+    "http://192.168.178.30:8090",   # LAN (nur wenn erreichbar)
+]
+HEIZ_API_BASES = [u for u in HEIZ_API_BASES if u]
+HEIZ_Z2M_URLS = [
+    "http://100.105.175.123:8080",
+    "http://192.168.178.30:8080",
+]
+HEIZ_EXPECTED_ONLINE = {
+    "wohnstube_links",
+    "wohnstube_rechts",
+    "schlafzimmer",
+    "flur_unten",
+    "trockenraum",
+    "buero",
+    "ankleideraum_oben",
+    "wc_unten",
+}
+HEIZ_BATTERY_WARN = 20
+
+
+def check_heizkoerper() -> list[str]:
+    """Vitalfunktionen Zigbee-Heizung CT152: API, z2m, TRV-Online, Batterie."""
+    alerts: list[str] = []
+    headers = {"User-Agent": "Mozilla/5.0 (Hausmeister-Bot/1.0 heizung-check)"}
+
+    zones = None
+    last_err = None
+    api_base = None
+    for base in HEIZ_API_BASES:
+        try:
+            r = requests.get(base + "/zones", timeout=8, headers=headers)
+            if r.status_code != 200:
+                last_err = f"HTTP {r.status_code}"
+                continue
+            zones = r.json()
+            api_base = base
+            break
+        except Exception as e:  # noqa: BLE001
+            last_err = str(e)[:80]
+    if zones is None:
+        alerts.append(
+            f"🔴 Heizung: heizsteuerung API nicht erreichbar ({HEIZ_API_BASES[0]}): {last_err}"
+        )
+        return alerts
+    if not isinstance(zones, list):
+        alerts.append("🔴 Heizung: /zones liefert unerwartete Antwort")
+        return alerts
+
+    by_id = {z.get("id"): z for z in zones if isinstance(z, dict) and z.get("id")}
+    offline = sorted(
+        zid for zid in HEIZ_EXPECTED_ONLINE
+        if zid not in by_id or not by_id[zid].get("online")
+    )
+    if offline:
+        alerts.append(
+            "🔴 Heizung: TRV offline (erwartet online): " + ", ".join(offline)
+        )
+
+    low_batt = []
+    for zid in sorted(HEIZ_EXPECTED_ONLINE):
+        z = by_id.get(zid) or {}
+        if not z.get("online"):
+            continue
+        batt = z.get("battery")
+        if batt is None:
+            continue
+        try:
+            if float(batt) < HEIZ_BATTERY_WARN:
+                low_batt.append(f"{zid} {int(float(batt))}%")
+        except (TypeError, ValueError):
+            continue
+    if low_batt:
+        alerts.append(
+            f"⚠️ Heizung: Batterie <{HEIZ_BATTERY_WARN}%: " + ", ".join(low_batt)
+        )
+
+    # z2m Frontend — Coordinator/UI tot?
+    z2m_ok = False
+    z2m_err = None
+    for url in HEIZ_Z2M_URLS:
+        try:
+            r = requests.get(url, timeout=6, headers=headers, allow_redirects=True)
+            if r.status_code < 500:
+                z2m_ok = True
+                break
+            z2m_err = f"HTTP {r.status_code}"
+        except Exception as e:  # noqa: BLE001
+            z2m_err = str(e)[:80]
+    if not z2m_ok:
+        alerts.append(f"🔴 Heizung: zigbee2mqtt Frontend nicht erreichbar: {z2m_err}")
+
+    # Abwesenheit laeuft, aber Backup leer = riskanter Zustand
+    try:
+        r = requests.get(api_base + "/abwesenheit", timeout=6, headers=headers)
+        if r.status_code == 200:
+            away = r.json()
+            if away.get("active") and not (away.get("backup_setpoints") or {}):
+                alerts.append(
+                    "⚠️ Heizung: Abwesenheit AN ohne Backup-Sollwerte"
+                )
+    except Exception:
+        pass
+
+    return alerts
+
+
 def check_hermes() -> list[str]:
     """Prueft Hermes (CT151) als kritischen Dienst ueber HTTP und Loki."""
     alerts = []
@@ -176,6 +288,7 @@ def check_all(state: dict | None = None) -> list[str]:
     suppressed_names = config.get_suppressed_container_names(cfg)
     alerts = []
     alerts.extend(check_hermes())
+    alerts.extend(check_heizkoerper())
     alerts.extend(loki_client.check_wp_mirror_sync())
 
     containers = proxmox_client.get_all_containers(
@@ -426,6 +539,18 @@ def _alert_key(alert_text: str) -> str:
         m = re.search(r"([\w.\-]+\.service)", alert_text)
         unit = m.group(1) if m else "generic"
         return hashlib.md5(("hermes|log|" + unit).encode()).hexdigest()
+    if "Heizung:" in alert_text:
+        if "API nicht erreichbar" in alert_text:
+            return hashlib.md5(b"heizung|api").hexdigest()
+        if "zigbee2mqtt Frontend" in alert_text:
+            return hashlib.md5(b"heizung|z2m").hexdigest()
+        if "TRV offline" in alert_text:
+            return hashlib.md5(b"heizung|trv_offline").hexdigest()
+        if "Batterie" in alert_text:
+            return hashlib.md5(b"heizung|battery").hexdigest()
+        if "Abwesenheit AN ohne Backup" in alert_text:
+            return hashlib.md5(b"heizung|away_backup").hexdigest()
+        return hashlib.md5(("heizung|" + alert_text[:60]).encode()).hexdigest()
     return hashlib.md5(alert_text.encode()).hexdigest()
 
 
@@ -450,6 +575,8 @@ def _alert_category(alert_text: str) -> str:
         return "restart"
     if "Hermes" in alert_text:
         return "hermes"
+    if "Heizung:" in alert_text:
+        return "heizung"
     if "Backup" in alert_text or "PBS" in alert_text:
         return "backup"
     if "Memory läuft ab" in alert_text: