What an AED self-test checks
An AED self-test is an automatic check of the battery, the pads and the internal circuits that runs on a schedule, without anyone pressing a button. Most models test daily or weekly, and many run a fuller test, including a charge of the shock circuit, once a month.
The schedule depends on the model. ZOLL’s AED Plus and AED 3 test every seven days by default, plus a monthly test at full energy. Philips HeartStart OnSite and FRx units test daily. HeartSine samaritan PAD units test once a week. The LIFEPAK CR2, Powerheart G5, Defibtech Lifeline and Avive Connect run daily, weekly and monthly tests. Most AEDs also test themselves when a new battery or pads cartridge goes in, and some every time they’re switched on.
What the test covers also varies, but it usually includes the battery’s charge, the circuits that deliver the shock and whether pads are connected. On many models it checks the pads’ and battery’s expiration dates too: ZOLL’s AED 3 manual, for example, tells the user to replace the pads immediately when the self-test finds they’ve passed their date.
A self-test has limits. It can’t tell that the AED was moved to a storage room, that a cabinet is blocked by furniture or that the rescue kit is missing. That’s why manufacturers still tell owners to look at the unit regularly, and why a person checks the AED as part of a monthly AED inspection.
What a red or flashing status light means
On almost every AED, a flashing or steady green light, or a green check, means the last self-test passed. A red light, a red X, a blank indicator or a beep means the AED found a problem and may not be ready to use.
A flashing light on its own isn’t a warning. Philips, HeartSine, Stryker’s LIFEPAK CR2, Defibtech and Avive all blink green to show they’re ready. ZOLL shows a green check in a small window on the handle, and the Powerheart G5 lights a green Rescue Ready indicator. The warning is the color: a status indicator flashing red, a red X or a red Rescue Ready light means the self-test failed or something needs attention.
No light at all is a warning too. On a HeartSine unit an indicator that has stopped flashing, and on a ZOLL AED 3 a blank status window, means the AED isn’t reporting ready, often because the battery is depleted.
An AED that beeps or chirps
A beep or chirp while the AED is switched off is how it asks for attention. Philips AEDs chirp once and flash the i-button for an issue you can usually fix yourself, and chirp three times for a problem that needs Philips. A Powerheart G5 beeps every 30 seconds, a LIFEPAK CR2 sounds an alert tone every 15 minutes, and HeartSine units give three quick beeps when they’re stored outside their temperature range. Don’t silence a beeping AED and walk away: find out what it’s telling you.
What to do if your AED self-test failed
Read what the AED is telling you, fix what you can (usually the battery or the pads), run a manual check, and call the manufacturer if the fault doesn’t clear. Until it does, the AED is out of service.
- Look and listen. Note exactly what the AED shows: a red light, a red X, a wrench or battery symbol, a message on the screen, or a pattern of beeps.
- Check the usual causes. An expired or missing pads cartridge, pads that have come unplugged, a low or expired battery, or a unit stored somewhere too hot or too cold.
- Follow the manual’s troubleshooting table for that indicator. It tells you what each symbol and beep means on your model.
- Run a manual check where your model allows it. Hold the On/Off button for about five seconds on a ZOLL AED Plus or AED 3 or a Defibtech Lifeline, press LANGUAGE and CHILD MODE together on a LIFEPAK CR2, or hold Power for five seconds on an Avive Connect. On a Philips unit, removing and reinserting the battery starts a test, but Philips warns that it uses battery power, so do it only when you need to.
- Call the manufacturer, or your AED service provider, if the warning comes back. Have the model and serial number ready.
- Write it down: what you saw, what you did, who you called and when the AED was back in service.
Also check whether the model is on an open recall. Our AED recall list shows recent FDA recalls by manufacturer and how to check a serial number.
When to take an AED out of service
Take an AED out of service whenever its indicator shows it isn’t ready, its pads or battery are expired or missing, it’s damaged, or the manufacturer tells you to. Put a working AED in its place, or tell responders where the nearest one is.
- The status indicator is red, blank or showing a service symbol, and the fault doesn’t clear.
- The pads or battery are past their expiration date, or missing.
- The AED has been used and its pads haven’t been replaced yet.
- The case is cracked, wet or visibly damaged.
- The manufacturer or the FDA has issued a recall that tells owners to stop using it.
Mark the AED as out of service in your records, so nobody counts it as ready, and put a note on the cabinet. In AED Log, a failed inspection marks the AED not safe to use and opens a corrective action, and marking a unit Out of service pauses its inspections while its pads and battery stay tracked. When the AED passes its next check, the flag clears on its own.
Status indicators by brand
Each manufacturer shows readiness a little differently. This table summarizes what the user manuals say; your own model’s manual is the final word.
| AED | Automatic self-test | Ready | Needs attention |
|---|---|---|---|
| ZOLL AED Plus | Every 7 days by default, plus a monthly test | Green check in the status window | Red X; a beep once a minute |
| ZOLL AED 3 | Every 7 days by default (or daily), plus a monthly test | Green check | Blank status window; a beep once a minute |
| Philips HeartStart OnSite and FRx | Daily | Ready light blinking green | Light off with chirps and a flashing i-button; triple chirps mean call Philips |
| HeartSine samaritan PAD 350P, 360P, 450P | Weekly | Status indicator flashing green | Flashing red, not flashing, or a continuous beep |
| Stryker LIFEPAK CR2 | Daily, weekly and monthly | Green indicator flashing every 6 seconds | Indicator not flashing, with an alert tone every 15 minutes |
| Stryker LIFEPAK 1000 | Daily and monthly | OK symbol on the display | Wrench (service) or battery symbol, or a CALL SERVICE prompt |
| ZOLL Powerheart G5 | Daily, weekly and monthly | Rescue Ready indicator green | Rescue Ready indicator red; a beep every 30 seconds |
| Defibtech Lifeline and Lifeline VIEW | Daily, weekly, monthly and quarterly | Status indicator flashing green | Red indicator with periodic beeps, or no light |
| Avive Connect | Daily, weekly and monthly | Status light blinking green | Status light blinking red, beeps, or both |
Older models and earlier versions can differ from current manuals. The LIFEPAK 1000 row, for example, comes from the only operating instructions Stryker still publishes for it, dated 2008. If your AED is no longer supported, the battery guide explains what that means for replacement parts.
AED self-test FAQ
How often does an AED test itself?
It depends on the model: most AEDs test daily or weekly, and many add a fuller monthly test. ZOLL AED Plus and AED 3 units test weekly by default, Philips HeartStart units daily and HeartSine samaritan PAD units weekly.
What does a red light on an AED mean?
A red light or a red X means the AED found a problem in its self-test and may not be ready. Check the pads and battery, follow your manual, and call the manufacturer if the warning doesn't clear. Treat the AED as out of service until it does.
Why is my AED beeping?
A beep or chirp while the AED is off means it needs attention, most often a low battery, missing or expired pads, or a failed self-test. Some models also beep when stored outside their temperature range. Your manual explains each pattern.
Can I run an AED self-test myself?
On many models, yes: hold the On/Off button for about five seconds on ZOLL and Defibtech units, press two buttons together on a LIFEPAK CR2, or hold Power on an Avive Connect. Philips warns its battery-reinsertion test uses power, so run it only when needed.
What happens when an AED fails an inspection?
AED Log opens a corrective action, marks the AED not safe to use and raises an alert for the people responsible. Resolve the corrective action or record a passing inspection, and the flag and the alert clear on their own.