Security & Fire Protection Systems/FA110C


QUESTION: Hi.  I recently moved to a home with the FA110c First Alert security System.  Just recently it's been going off once a day, every day.  I enter the code and press "OFF" and it goes off, but not for long.  Today, I noticed it says BAT on the display.  We have two sensors on two doors, I took out the batteries on those, but the alarm didn't stop.  So to get it to stop, I just entered code and pressed OFF.  Now it's flashing AC, NOT READY and BAT, then switches to 09 AC CHECK and then 10 AC CHECK etc.  I have NO clue what to do, or how to fix this.  Do I need two new batteries in the door sensors? Once I get new ones and replace those, will the random beeping go off?  I don't know what AC means either?  Arrggg  so confused.  Please help!  Thanks!!!

ANSWER: Hello Justina, and thanks for your question.

I think there are a couple of things going on.

First, you keypad will show low battery for your sensors by displaying something like BAT 01, with the number corresponding to the zone that the wireless sensor is on. Removing the battery from the sensor wont stop that; in fact "no battery" is worse than "low battery."

So go ahead and replace those batteries with hew ones.

The flashing AC, coupled with BAT without a zone number sounds like the plug-in transformer for the system may be unplugged, or the outlet has been turned off at the breaker box. #AC means "alternating current" and all this really means is regular house current.# This is the main backup battery, which powers the system when there's a power outage. So check that all the breakers are on, and if you know where the alarm transformer is #it'll be plugged into a wall outlet near to the control box#, check to see if it's plugged in. If it is plugged in, it should be warm to the touch.

Let me know what you find, and we'll take it from there.

Best Regards,


[an error occurred while processing this directive]---------- FOLLOW-UP ----------

QUESTION: I replaced the batteries, and I check the plug in, it's screwed into the outlet, so that's not the issue.  I also checked the breaker and that's fine too.  Now, this is what's going on the display.  The first flash is AC NOT READY and BAT.  The second one is FC AC NOT READY BAT, the third is 09 CHECK AC and the 4th is 10 CHECK AC.  It just keeps flashing these words scrolling thru and then starting over.  Any ideas?  Thank you so much for your help!

Thanks for the update, and for checking the transformer.

It looks like three separate issues, and this in part is why the messages are so confusing -- there are different messages that are separate, but they read as if they are one thing. Let's go through them all.

First the "AC" is normal. If it says NO AC, then that's a problem.

The next "is NOT READY." This means that the alarm is not ready to be set because a door or window is open, or there is some other problem with the protection.

Next you have "FC" which is "failure to communicate." This means that the control tried to contact the monitoring center to report an alarm or trouble, but failed. This could make sense since you recently moved in. The previous owners have probably cancelled any monitoring contract that they had.

The next message is "BAT." This is the system backup battery which is in the main control box. It needs to be replaced.

The final two are "09 CHECK" and "10 CHECK." I believe these are related to the "NOT READY" message. The open doors, windows, or other protection is located on zones 09 and 10. So close all of the doors and windows, and those troubles should go away.

The biggest problem you have is the FC trouble. That's going to require a technician to make a programming change.

All of this information is likely to create more questions -- I'll answer them as best I can.

Best Regards,


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Dave Neuweiler


The design and application of burglary and fire systems for homes and businesses. Helping alarm owners understand how their system works. Helping to troubleshoot false alarm problems. Questions about monitoring issues.


Over a quarter century in the industry. Experience in installation, service, and monitoring centers. Training manager for a national protective services company; director of education and training for a national trade organization for for alarm dealers.


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