diff --git a/apps/rules/rule_interface.py b/apps/rules/rule_interface.py
index 47c4482..f47aa74 100644
--- a/apps/rules/rule_interface.py
+++ b/apps/rules/rule_interface.py
@@ -246,6 +246,23 @@ class RedisState:
         
         await self._execute_with_retry(_expire, key, ttl_secs)
     
+    async def delete(self, key: str) -> None:
+        """
+        Delete a key from Redis.
+        
+        Args:
+            key: Redis key to delete
+            
+        Example:
+            >>> state = RedisState("redis://localhost:6379/0")
+            >>> await state.set("rules:r1:temp", "22.5")
+            >>> await state.delete("rules:r1:temp")
+        """
+        async def _delete(client, k):
+            await client.delete(k)
+        
+        await self._execute_with_retry(_delete, key)
+    
     async def close(self) -> None:
         """
         Close Redis connection and cleanup resources.
diff --git a/apps/ui/templates/dashboard.html b/apps/ui/templates/dashboard.html
index 6c9280a..b6cbfc9 100644
--- a/apps/ui/templates/dashboard.html
+++ b/apps/ui/templates/dashboard.html
@@ -365,32 +365,59 @@
             color: #999;
         }
         
-        .temp-controls {
+        /* Thermostat Slider Styles */
+        .thermostat-slider-control {
+            margin: 1rem 0;
+        }
+        
+        .thermostat-slider-label {
             display: flex;
-            gap: 0.5rem;
-            margin-bottom: 1rem;
+            justify-content: space-between;
+            align-items: center;
+            margin-bottom: 0.5rem;
+            font-size: 0.875rem;
+            color: #666;
         }
         
-        .temp-button {
-            flex: 1;
-            padding: 0.75rem;
-            border: none;
-            border-radius: 8px;
-            font-size: 1.125rem;
-            font-weight: 700;
+        .thermostat-slider {
+            width: 100%;
+            height: 8px;
+            border-radius: 4px;
+            background: linear-gradient(to right, #667eea 0%, #764ba2 100%);
+            outline: none;
+            -webkit-appearance: none;
+            appearance: none;
             cursor: pointer;
-            transition: all 0.2s;
-            background: #667eea;
-            color: white;
-            min-height: 44px;
         }
         
-        .temp-button:hover {
-            background: #5568d3;
+        .thermostat-slider::-webkit-slider-thumb {
+            -webkit-appearance: none;
+            appearance: none;
+            width: 24px;
+            height: 24px;
+            border-radius: 50%;
+            background: white;
+            border: 3px solid #667eea;
+            cursor: pointer;
+            box-shadow: 0 2px 4px rgba(0,0,0,0.2);
         }
         
-        .temp-button:active {
-            transform: scale(0.95);
+        .thermostat-slider::-moz-range-thumb {
+            width: 24px;
+            height: 24px;
+            border-radius: 50%;
+            background: white;
+            border: 3px solid #667eea;
+            cursor: pointer;
+            box-shadow: 0 2px 4px rgba(0,0,0,0.2);
+        }
+        
+        .thermostat-slider-range {
+            display: flex;
+            justify-content: space-between;
+            margin-top: 0.25rem;
+            font-size: 0.75rem;
+            color: #999;
         }
         
         /* Contact Sensor Styles */
@@ -398,6 +425,7 @@
             display: flex;
             align-items: center;
             gap: 0.75rem;
+
             padding: 1rem;
             background: #f8f9fa;
             border-radius: 8px;
@@ -965,13 +993,23 @@
                             </div>
                         </div>
                         
-                        <div class="temp-controls">
-                            <button class="temp-button" onclick="adjustTarget('{{ device.device_id }}', -1.0)">
-                                -1.0
-                            </button>
-                            <button class="temp-button" onclick="adjustTarget('{{ device.device_id }}', 1.0)">
-                                +1.0
-                            </button>
+                        <div class="thermostat-slider-control">
+                            <label class="thermostat-slider-label">
+                                <span>🎯 Zieltemperatur</span>
+                            </label>
+                            <input type="range" 
+                                   min="5" 
+                                   max="30" 
+                                   step="0.5" 
+                                   value="21.0" 
+                                   class="thermostat-slider"
+                                   id="slider-{{ device.device_id }}"
+                                   oninput="updateThermostatDisplay('{{ device.device_id }}', this.value)"
+                                   onchange="setThermostatTarget('{{ device.device_id }}', this.value)">
+                            <div class="thermostat-slider-range">
+                                <span>5°C</span>
+                                <span>30°C</span>
+                            </div>
                         </div>
                         
                         {% elif device.type == "contact" or device.type == "contact_sensor" %}
@@ -1327,6 +1365,7 @@
         function updateThermostatUI(deviceId, current, target, mode) {
             const currentSpan = document.getElementById(`state-${deviceId}-current`);
             const targetSpan = document.getElementById(`state-${deviceId}-target`);
+            const slider = document.getElementById(`slider-${deviceId}`);
             
             if (current !== undefined && currentSpan) {
                 currentSpan.textContent = current.toFixed(1);
@@ -1336,6 +1375,10 @@
                 if (targetSpan) {
                     targetSpan.textContent = target.toFixed(1);
                 }
+                // Sync slider with actual state
+                if (slider) {
+                    slider.value = target;
+                }
                 thermostatTargets[deviceId] = target;
             }
         }
@@ -1733,6 +1776,46 @@
             }
         }
         
+        // Update thermostat display while dragging slider
+        function updateThermostatDisplay(deviceId, value) {
+            const targetElement = document.getElementById(`state-${deviceId}-target`);
+            if (targetElement) {
+                targetElement.textContent = `${parseFloat(value).toFixed(1)}°C`;
+            }
+        }
+        
+        // Set thermostat target temperature when slider is released
+        async function setThermostatTarget(deviceId, value) {
+            try {
+                const targetTemp = parseFloat(value);
+                
+                const response = await fetch(api(`/devices/${deviceId}/set`), {
+                    method: 'POST',
+                    headers: { 'Content-Type': 'application/json' },
+                    body: JSON.stringify({
+                        target_temperature: targetTemp
+                    })
+                });
+                
+                if (!response.ok) {
+                    const error = await response.json();
+                    throw new Error(error.detail || 'Request failed');
+                }
+                
+                console.log(`Thermostat ${deviceId} target set to ${targetTemp}°C`);
+                
+                addEvent({
+                    action: 'thermostat_set',
+                    device_id: deviceId,
+                    target_temperature: targetTemp
+                });
+                
+            } catch (error) {
+                console.error('Failed to set thermostat target:', error);
+                showToast(`Fehler beim Setzen der Zieltemperatur: ${error.message}`, 'error');
+            }
+        }
+        
         // Execute group action
         async function setGroup(groupId, power, buttonElement) {
             const allButtons = buttonElement.parentElement.querySelectorAll('button');