Honeywell Home Security F24 Fix (Error Code Guide)

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What This Error Means

F24 on a Honeywell Home security system is a generic internal fault code. The panel or base station has crashed or detected a hardware problem and has dropped into a safe-fail mode.

In plain terms: the brain of the system is unstable, so arming, alerts, or cloud connection may not work reliably until you clear the fault.

Note: Honeywell doesn’t publicly list F24 in most user manuals. When it shows, they treat it as a “service required, call support” condition.

Official Fix

What Honeywell support will walk you through, step by step:

  • 1. Make the system safe first.
    • If you have professional monitoring, call the monitoring company and put the system in test mode before you start pulling power.
    • Warn anyone at home that the alarm and beeps may start or stop while you work.
  • 2. Do a clean power cycle.
    • Disarm the system if it will let you.
    • Unplug the low-voltage power adapter or shut off the breaker feeding the alarm transformer.
    • If you have a metal can with a separate control board, open it and disconnect the backup battery leads (red and black spade connectors).
    • Wait at least 60 seconds so the board fully discharges.
    • Reconnect the battery first, then restore mains power.
    • Let the panel or base station boot completely and check if F24 cleared.
  • 3. Check the network side.
    • Make sure your internet is up and the router is not rebooting or overloaded.
    • If your Honeywell panel uses Wi‑Fi, run the Wi‑Fi test or re-join the network from the menu or app.
    • If it uses Ethernet, reseat both ends of the cable and try a different router port if you have one.
  • 4. Run a system test from the keypad or app.
    • Most Honeywell Home panels have a “System Test” or “Walk Test” option in settings.
    • Run the test and watch for any specific sensor or module that fails; if F24 returns immediately with no other detail, the fault is inside the main unit.
  • 5. If F24 comes back quickly, contact Honeywell or your installer.
    • At that point, the official line is “board or base station likely failed”.
    • They will usually recommend replacing the main panel or smart base if it is out of warranty.

The Technician’s Trick

What techs actually do when F24 keeps coming back and the script says “replace the panel”:

  • 1. Bare-bones power test.
    • Kill power again: unplug the transformer and disconnect the battery.
    • If you have a can-style panel, label and remove all field wires from the terminals (zones, siren, keypads, phone/cellular, anything that is not power).
    • Reconnect just the battery and transformer so the board is running with no field wiring.
    • If F24 disappears in this stripped-down state, one of those removed circuits is dragging the panel down.
    • Reconnect half the wires at a time until the error returns. That tells you which cable, sensor loop, or keypad is the culprit.
  • 2. Hard reset on all-in-one touchscreens.
    • On the self-contained Honeywell Home units (tablet-style), there are usually two levels of reset: a normal reboot and a full factory reset.
    • If a normal power cycle and Wi‑Fi reset do nothing, back up any settings you can in the app.
    • Then run the factory reset from the hidden installer/advanced menu and set the system up again from scratch.
    • If F24 survives a full factory reset, the main board is almost certainly bad.
  • 3. Temporary downgrade, but at least you stay protected.
    • If one ugly old wired zone keeps tripping F24, a tech will sometimes leave it disconnected, program that zone as unused, and keep the rest of the system live.
    • It is not perfect, but it is better than running with a brain-dead panel or no alarm at all while you decide on a full upgrade.
    • If any of this feels over your head, stop now and get a pro on-site. Low-voltage alarm wiring is usually safe, but mains wiring and transformers are not for guessing.

Is It Worth Fixing? (The Financial Verdict)

  • ✅ Fix: System is under 8–10 years old, F24 clears after a clean power cycle or a single bad sensor/zone is found, and any replacement parts are under about $150.
  • ⚠️ Debatable: Panel is 10–15 years old, you need a new main board and maybe a keypad, and the quote lands in the $200–$400 range but you really want to keep existing wired sensors.
  • ❌ Replace: The system is older than 15 years, F24 keeps coming back even after parts swaps, or the repair quote is more than half the cost of a modern smart alarm kit with better app support.

Parts You Might Need

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See also

Dealing with other F-series and smart-home error codes? These guides might save you more time: