diff --git a/backend/src/routes/override.js b/backend/src/routes/override.js
index 4ac9dca..a020583 100644
--- a/backend/src/routes/override.js
+++ b/backend/src/routes/override.js
@@ -29,16 +29,26 @@ export async function overrideRoutes(app) {
       return reply.status(200).send({ ok: false, error: 'No TRVs mapped to this zone', auto_mode: false })
     }
 
-    const results = await batchSetZoneTemperature(devices, tempC)
-    const successful = Object.values(results).filter(Boolean).length
+    // Don't block the HTTP response on the full per-device retry/backoff pipeline —
+    // setTargetWithRetry() (called per-device inside batchSetZoneTemperature, plus
+    // a ~10s stagger between devices) can run up to ~93 minutes before giving up
+    // (RETRY_DELAYS_MS in lib/mqtt.js: 30s->30min x10 attempts), which any reverse
+    // proxy will time out on long before that finishes — hit as a real Gateway
+    // Time-out 2026-08-26. Fire it in the background instead; the frontend already
+    // reads the eventual outcome back via GET .../trv-status (setpoint/health_state)
+    // per device, same eventually-consistent pattern the MHI/Daikin panels use.
+    batchSetZoneTemperature(devices, tempC)
+      .then(results => {
+        const successful = Object.values(results).filter(Boolean).length
+        return logActivity(zone.id, 'override', {
+          note: `Manual override to ${tempC}°C (${successful}/${devices.length} devices, auto mode disabled)`,
+          source: 'manual',
+          userEmail: req.user.email,
+        })
+      })
+      .catch(err => req.log.error(`[override] background retry failed: ${err.message}`))
 
-    await logActivity(zone.id, 'override', {
-      note: `Manual override to ${tempC}°C (${successful}/${devices.length} devices, auto mode disabled)`,
-      source: 'manual',
-      userEmail: req.user.email,
-    })
-
-    return { ok: successful > 0, successful, total: devices.length, auto_mode: false }
+    return { ok: true, pending: true, total: devices.length, auto_mode: false }
   })
 
   // GET /api/devices/:id/mhi-status — live status for one assigned MHI aircon unit.
@@ -181,14 +191,19 @@ export async function overrideRoutes(app) {
     const tempC = Number(req.body?.tempC)
     if (!Number.isFinite(tempC)) return reply.status(400).send({ error: 'tempC must be a number' })
 
-    const ok = await setTargetWithRetry({ external_ref: device.external_ref, device_ip: device.device_ip }, tempC)
+    // Don't block the HTTP response on the full retry/backoff pipeline — it can run
+    // up to ~93 minutes (see the same note on /api/zones/:id/override above) before
+    // giving up, which any reverse proxy will time out on long before that finishes.
+    // Fire it in the background; GET .../trv-status already reflects the eventual
+    // setpoint/health_state once it resolves, same as every other device panel.
+    setTargetWithRetry({ external_ref: device.external_ref, device_ip: device.device_ip }, tempC)
+      .then(ok => logActivity(device.zone_id, 'device_command', {
+        note: `TRV manual setpoint on ${device.location || device.discovered_name || device.external_ref}: ${tempC}°C${ok ? '' : ' — FAILED to acknowledge'}`,
+        source: 'manual',
+        userEmail: req.user.email,
+      }))
+      .catch(err => req.log.error(`[trv-control] background retry failed: ${err.message}`))
 
-    await logActivity(device.zone_id, 'device_command', {
-      note: `TRV manual setpoint on ${device.location || device.discovered_name || device.external_ref}: ${tempC}°C${ok ? '' : ' — FAILED'}`,
-      source: 'manual',
-      userEmail: req.user.email,
-    })
-
-    return { ok }
+    return { ok: true, pending: true }
   })
 }
diff --git a/frontend/src/api.ts b/frontend/src/api.ts
index aa934e1..3d8de7b 100644
--- a/frontend/src/api.ts
+++ b/frontend/src/api.ts
@@ -63,7 +63,12 @@ export function fetchActivity(zoneId?: number, limit = 100): Promise<ActivityEnt
 }
 
 // Override
-export function overrideZone(id: number, tempC: number): Promise<{ ok: boolean; successful: number; total: number; auto_mode: boolean; error?: string }> {
+// successful/total confirmation isn't available synchronously any more — the
+// backend fires the retry/backoff pipeline in the background rather than
+// blocking the response on it (up to ~93 minutes, guaranteed proxy timeout).
+// `pending: true` means "commands sent, applying" — read GET .../trv-status
+// per device for the eventual real outcome.
+export function overrideZone(id: number, tempC: number): Promise<{ ok: boolean; pending?: boolean; total: number; auto_mode: boolean; error?: string }> {
   return request(`/zones/${id}/override`, { method: 'POST', body: JSON.stringify({ temp_c: tempC }) })
 }
 
diff --git a/frontend/src/components/KioskBulkPanel.tsx b/frontend/src/components/KioskBulkPanel.tsx
index 51920d2..164cbe8 100644
--- a/frontend/src/components/KioskBulkPanel.tsx
+++ b/frontend/src/components/KioskBulkPanel.tsx
@@ -50,7 +50,11 @@ export default function KioskBulkPanel({ devices, onDone }: Props) {
       await new Promise(r => setTimeout(r, TRV_STAGGER_MS))
     }
     setApplyingTrv(false)
-    setResults(r => [...r, `TRVs: ${trvIds.length - failed}/${trvIds.length} updated${failed ? ' — some failed' : ''}`])
+    // The backend now fires each TRV's retry/backoff pipeline in the background
+    // rather than blocking on it (see routes/override.js) — this only confirms the
+    // command was SENT, not that the valve has actually acknowledged it yet. Check
+    // the zone tiles' setpoint a little later for the real outcome.
+    setResults(r => [...r, `TRVs: sent to ${trvIds.length - failed}/${trvIds.length}${failed ? ' — some failed to send' : ''} — applying in the background`])
   }
 
   async function applyAc() {
diff --git a/frontend/src/components/TrvControlPanel.tsx b/frontend/src/components/TrvControlPanel.tsx
index ed32a7d..decb450 100644
--- a/frontend/src/components/TrvControlPanel.tsx
+++ b/frontend/src/components/TrvControlPanel.tsx
@@ -23,8 +23,12 @@ function timeAgo(iso: string | null | undefined): string {
 // displayed value immediately but the MQTT command is debounced 1s after the last
 // click — these are battery/deep-sleep valves going through the full retry/backoff
 // pipeline (setTargetWithRetry), so rapid-fire clicking shouldn't fire a command per
-// click. Read side is push-populated (mqtt.js keeps the row fresh from
-// shellies/+/status + shellies/+/info), same "read the row" shape as Mhi/Daikin panels.
+// click. That retry pipeline runs in the backend background now (routes/override.js),
+// not awaited by the HTTP response — sendTrvControl() resolving ok:true only means
+// the command was sent, not that the valve has acknowledged it yet. Read side is
+// push-populated (mqtt.js keeps the row fresh from shellies/+/status +
+// shellies/+/info), same "read the row" shape as Mhi/Daikin panels — refresh (the
+// button below) to see the real outcome once the valve responds.
 export default function TrvControlPanel({ deviceId, canControl }: { deviceId: number; canControl: boolean }) {
   const [loading, setLoading] = useState(true)
   const [error, setError] = useState('')
diff --git a/frontend/src/components/ZoneDetailModal.tsx b/frontend/src/components/ZoneDetailModal.tsx
index 01a8ae9..02090a0 100644
--- a/frontend/src/components/ZoneDetailModal.tsx
+++ b/frontend/src/components/ZoneDetailModal.tsx
@@ -134,7 +134,7 @@ export default function ZoneDetailModal({ zone, onClose, onSaved }: {
     try {
       const res = await overrideZone(zone.id, Number(overrideTemp))
       if (res.ok) {
-        setMsg(`Set to ${overrideTemp}°C (${res.successful}/${res.total} devices) — auto mode disabled`)
+        setMsg(`Sent ${overrideTemp}°C to ${res.total} device${res.total === 1 ? '' : 's'} — applying in the background, auto mode disabled`)
         setAutoMode(false)
         onSaved()
       } else {