diff --git a/lib/ai/providers/openai-image.ts b/lib/ai/providers/openai-image.ts
index ca0a350b5..2e8e546cb 100644
--- a/lib/ai/providers/openai-image.ts
+++ b/lib/ai/providers/openai-image.ts
@@ -25,6 +25,7 @@ interface UploadedImage {
 
 const DEFAULT_IMAGE_SIZE = "2K";
 const DEFAULT_TIMEOUT_MS = 300000;
+const LONG_RUNNING_COMFLY_TIMEOUT_MS = 590000;
 const OPENAI_IMAGE_MIN_TOTAL_PIXELS = 3_686_400;
 const OPENAI_IMAGE_DIMENSION_MULTIPLE = 16;
 const BLTCY_HOST_REGEX = /(^|\.)bltcy\.ai$/i;
@@ -216,6 +217,13 @@ function resolveProviderImageSize(
   return resolveOpenAISize(aspectRatio, imageSize);
 }
 
+function resolveRequestTimeoutMs(baseURL: string, imageSize?: "1K" | "2K" | "4K") {
+  if (isComflyBaseURL(baseURL) && imageSize === "4K") {
+    return LONG_RUNNING_COMFLY_TIMEOUT_MS;
+  }
+  return DEFAULT_TIMEOUT_MS;
+}
+
 function normalizeQuality(value?: string) {
   const normalized = String(value || "").trim().toLowerCase();
   if (normalized === "low" || normalized === "medium" || normalized === "high") {
@@ -453,9 +461,10 @@ async function requestOpenAIImageGeneration(params: {
     typeof aspectRatio === "string" && aspectRatio.trim() && aspectRatio !== "auto"
       ? aspectRatio.trim()
       : undefined;
+  const timeoutMs = resolveRequestTimeoutMs(baseURL, imageSizeLabel);
 
   const controller = new AbortController();
-  const timeoutId = setTimeout(() => controller.abort(), DEFAULT_TIMEOUT_MS);
+  const timeoutId = setTimeout(() => controller.abort(), timeoutMs);
 
   try {
     if (imageUrls.length > 0) {
@@ -588,6 +597,7 @@ export function createOpenAIImage({ apiKey, baseURL }: OpenAIImageConfig) {
           promptAspectRatio: promptAspectRatio || undefined,
           imageSize,
           resolutionMode: isComflyBaseURL(baseURL) ? "longest-edge" : "pixel-area",
+          timeoutMs: resolveRequestTimeoutMs(baseURL, imageSize),
           useBltcyImageCompatParams: shouldUseBltcyImageCompatParams(baseURL),
           imageCount: imageUrls.length,
           baseURL: normalizeBaseURL(baseURL),
diff --git a/lib/ai/runtime/model-health.ts b/lib/ai/runtime/model-health.ts
index 4d19aea38..3530c01ab 100644
--- a/lib/ai/runtime/model-health.ts
+++ b/lib/ai/runtime/model-health.ts
@@ -89,6 +89,22 @@ export function classifyAiModelHealthFailure(error: unknown): {
     };
   }
 
+  if (
+    normalized.includes("fetch failed") ||
+    normalized.includes("econnreset") ||
+    normalized.includes("econnrefused") ||
+    normalized.includes("socket hang up") ||
+    normalized.includes("networkerror") ||
+    normalized.includes("network error")
+  ) {
+    return {
+      eventType: "unavailable",
+      severity: "warning",
+      counted: false,
+      reason: "transport_failure_no_provider_response",
+    };
+  }
+
   if (
     normalized.includes("model not exist") ||
     normalized.includes("model_not_found") ||
@@ -133,9 +149,9 @@ export function classifyAiModelHealthFailure(error: unknown): {
   ) {
     return {
       eventType: "timeout",
-      severity: "critical",
-      counted: true,
-      reason: "timeout",
+      severity: "warning",
+      counted: false,
+      reason: "timeout_without_provider_response",
     };
   }
 
@@ -150,8 +166,7 @@ export function classifyAiModelHealthFailure(error: unknown): {
     normalized.includes("no available channel") ||
     normalized.includes("no supported channel") ||
     normalized.includes("service unavailable") ||
-    normalized.includes("fetch failed") ||
-    normalized.includes("econnreset")
+    normalized.includes("temporarily unavailable")
   ) {
     return {
       eventType: "unavailable",
@@ -184,7 +199,32 @@ export function classifyAiModelHealthFailure(error: unknown): {
 }
 
 export function shouldFailoverAiModelError(error: unknown) {
-  return classifyAiModelHealthFailure(error).counted;
+  const classification = classifyAiModelHealthFailure(error);
+  if (!classification.counted) return false;
+
+  const normalized = getErrorMessage(error).toLowerCase();
+  if (classification.eventType === "timeout" || classification.eventType === "download_error") {
+    return false;
+  }
+  if (classification.eventType === "invalid_model" || classification.eventType === "quota") {
+    return true;
+  }
+  if (classification.eventType === "unavailable") {
+    return (
+      /(?:^|\D)(?:429|500|502|503|504)(?:\D|$)/.test(normalized) ||
+      normalized.includes("no available channel") ||
+      normalized.includes("no supported channel") ||
+      normalized.includes("service unavailable") ||
+      normalized.includes("temporarily unavailable") ||
+      normalized.includes("model maintenance") ||
+      normalized.includes("maintenance") ||
+      normalized.includes("修复中") ||
+      normalized.includes("系统繁忙") ||
+      normalized.includes("无可用渠道")
+    );
+  }
+
+  return /(?:^|\D)[45]\d\d(?:\D|$)/.test(normalized);
 }
 
 function buildMetadata(value?: Record<string, unknown>) {