Cisco ACS-2821-51-FANS
Cisco 2821/51 Fan Replacement Kit
Product Highlights
Aging fans are one of the most common failure points in rack-mounted networking equipment. When a fan fails or degrades in your Cisco 2821 or 2851 Integrated Services Router, the chassis can overheat — triggering thermal alarms, performance throttling, or even an unexpected shutdown that takes your branch office or WAN edge offline.
The Cisco ACS-2821-51-FANS is the official fan replacement kit for the Cisco 2821 and Cisco 2851 routers. Each kit includes three 80mm chassis fans with 3-pin connectors, providing everything you need to fully refresh the cooling system in a single maintenance window. The fans are designed to meet original manufacturer specifications for airflow and RPM, restoring reliable thermal management to your router.
While the Cisco 2800 Series has reached End-of-Life status, thousands of these routers remain in production across branch offices, labs, and managed-service environments. Replacing worn fans with the ACS-2821-51-FANS kit is a practical, low-cost way to extend the operational life of your existing Cisco 2821 or 2851 investment — avoiding a premature forklift upgrade while you plan your migration path to newer ISR platforms.
Features & Benefits
Complete 3-Fan Cooling Kit
The ACS-2821-51-FANS kit includes all three chassis fans needed for the Cisco 2821 and 2851 routers. By replacing the full set at once, you ensure uniform airflow across the chassis and avoid the risk of a second fan failure shortly after addressing the first.
Drop-In Installation
Each 80mm fan features a standard 3-pin power connector that plugs directly into the router's fan headers. No soldering, adapters, or chassis modifications are required — making this a straightforward maintenance task for on-site IT staff.
Thermal Protection & Uptime
Failed or degraded fans can cause the Cisco IOS to generate low-RPM alarms, illuminate fault LEDs, or initiate a protective thermal shutdown. Replacing fans proactively eliminates these risks and keeps your router operating within its designed temperature envelope.
Cost-Effective Lifecycle Extension
For organizations still running Cisco 2800 Series routers, a fan kit is a fraction of the cost of a new chassis or platform migration. It buys valuable time to plan and budget for an upgrade to the Cisco ISR G2 or ISR 4000 Series on your own schedule.
Deployment Scenarios
Branch Office Router Maintenance
Branch offices relying on a Cisco 2821 or 2851 for WAN connectivity, VPN, and voice services cannot afford unplanned downtime. Stocking a fan replacement kit enables rapid on-site repair when a fan failure alarm is triggered, restoring full cooling without waiting for a replacement chassis.
Lab & Training Environments
Cisco 2800 Series routers remain popular in CCNA/CCNP lab environments. Replacing worn fans keeps lab equipment functional and quiet, extending the useful life of hardware that is otherwise difficult to source new.
Managed Service Provider Spare Inventory
MSPs supporting legacy Cisco infrastructure across multiple client sites benefit from keeping fan kits in their spare parts inventory. A quick fan swap during a scheduled maintenance window prevents escalation to a costly emergency visit.
General
Fan Specifications
Cross-Reference
Compatibility Notes
Compatible Platforms
- Cisco 2821 Integrated Services Router (CISCO2821)
- Cisco 2851 Integrated Services Router (CISCO2851)
Alternative / Cross-Reference Part Numbers
- ACS-2821-51-FANS= (orderable spare variant)
- 700-19154-01
- 700-19155-01
- 800-23841-01 / 800-23841-02 (individual fan part numbers)
Important Notes
- The Cisco 2800 Series ISR platform has reached End-of-Life (EOL) status. Cisco recommends migration to the Cisco 2900, 3900, or 4000 Series ISR G2 platforms.
- Fan trays/caddies are not included in this kit — only the fan units themselves. Reuse your existing fan trays.
- This kit contains fans only; no screws, cables, or documentation are guaranteed unless specified in the "What's Included" section.
Downloads & Resources
Frequently Asked Questions
| Part Number | Product | Key Difference |
|---|---|---|
| ACS-2821-51-FAN | Cisco 2821/2851 Single Replacement Fan | Single fan unit vs. the full 3-fan kit — choose this if only one fan position needs replacement. |
| PWR-2821-51-AC | Cisco 2821/2851 AC Power Supply | Replacement AC power supply for the same router platform — commonly purchased alongside fan kits during chassis refurbishment. |
| ACS-2821-51-FAN-1/2 | Cisco 2821/2851 Fan 1/2 Replacement | Individual chassis fan for fan slot 1 or 2 — a targeted option when only a specific fan position has failed. |
