What does a bF error on a Honeywell alarm keypad mean?

If you're getting a new bF error today, it's likely because you have an old 2G communicator and will need to replace it.

AT&T has finally sunset their 2G network. It no longer works as of January 1st. While Alarm Grid offers free phone support for any customer that is monitored by us, for everyone else, there is the FAQs on the site.

If you'd like to understand your monitoring options, please call talkdesk888-818-7728, or you can sign up for a plan today!

  • If you have a VISTA 10P, 15P, or 20P, then you will need a GSMV4G-TC2 or a GSMX4G-TC2 to get your system back online.
  • If you have a LYNX Touch system, but do not know which system you have, we have put together an identification guide for you.
  • If you have an old L5000, then you will need to replace it if you would like to continue cellular service. There is no 3G communicator for it. The current LYNX Touch is the L5210 or the bigger screened L7000. Consider also the Lyric security system which will work with all your old sensors. The Lyric-3G is the communicator for that unit, and it supports WIFI as well.
  • The L5100's communicator can be replaced with a GSMVLP5-4G or the newer 3GL. The 3GL does work in those older units, but the GSMVLP5-4G was built specifically for the L5100 and we would recommend it over the 3GL.
  • The L5200, L5210, and L7000 were never released with 2G communicators. Hurrah!

bF, or sometimes seen as 6 (six) F, on a fixed English alarm keypad stands for "backup failure", and indicates a problem with an AlarmNet alarm monitoring communicator. AlarmNet alarm communicators are also called Long Range Radios (LRR) and a bF trouble signal may be associated with many different LRR trouble conditions. There are many common reasons a bF may be displayed. Cover Tamper, the communicator not being registered, loss of communication between the panel and the AlarmNet device, failure to receive acknowledgement of a signal transmitted within a certain amount of time, loss of network connection, and in some cases power/battery issues.

One of the most common reasons for a bF trouble signal is that the alarm communicator was not able to successfully transmit an alarm signal. If you have an internet alarm communicator, that could mean your internet connection is down. Perhaps there was a power outage and your modem and router lost power, or your internet service provider (ISP) may have had an interruption in service. If you have a cellular alarm communicator, the device may have lost connection with the cellular network in your area. You can check with your AlarmNet dealer to see if your cellular communicator had a drop in cellular signal strength. These communication failure situations can resolve themselves, and if the connection is restored, the AlarmNet alarm communicator should be able to automatically restore communications. The bF trouble signal will remain on your keypad until you acknowledge the trouble by pressing your code followed by the 'OFF' key, twice. Your Honeywell security system wants to make sure that you are aware of the issue, even if it has already restored, and that is why the bF signal will remain on the keypad display until acknowledged, even if the trouble condition is no longer present.

Another common reason for the bF signal, when first activating an AlarmNet communicator, is that the cover on the device is removed. AlarmNet devices have a built-in tamper so that you will be alerted if someone removes the cover of your communicator. When first activating your AlarmNet communicator, you have to remove the cover and therefore, many people end up getting the bF trouble signal once the device is active. If you simply put the cover back in place, and then go through a disarm sequence on your keypad (code + OFF), the bF signal should clear.

If you had an alphanumeric alarm keypad, the bF signal would actually be displayed as a 'Check 103, Long Rng Trbl' which is short for a trouble with the long range radio. In this case, a 4 digit trouble code will be displayed, which will tell you exactly what the problem is:

Status Code



Control Panel lost communication with AlarmNet Device


AlarmNet Device Cover Tamper Detected (Cover Removed)


Communicator has lost contact with the AlarmNet Cellular Network


Communicator has lost contact with AlarmNet


Communicator is not registered; account not activated


Communicator Shut Down


Communicator Power-on Reset AND the panel lost communicator with AlarmNet Device


Communicator Power-on Reset AND Tamper Detected


Communicator Power-on Reset AND Tamper Detected AND Device Not Registered


Communicator Tamper Detected AND Communicator Low Battery


Primary Power Loss (will only be displayed in conjunction with another event)


Battery Charger Fail (will only be displayed in conjunction with another event)


Low Battery (will only be displayedi n conjunction with another event)

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The 6 is actually a lower case b so it's bF that you are seeing on the system and the information above explains why you'd see that error. What system and alarm communicator do you have?
What does it mean when the system says '6f check'? I'm trying to get the door chime to work again but when I press code + chime it doesn't work.
Which panel do you have? Feel free to email us photos to support@alarmgrid.com if you are unsure. You will need to disable the communication settings. Do you have an active installer code?
Please help. Due to problems with the alarm company we have discontinued monitoring service with them now with that being said we still want to use the alarm system but lately for no reason at all the Alarm goes off in the middle of the night. Doors and windows are fine and nothing seems out of place. We do have the check 6f and fc on panel. Called company that installed and said they could not do anything unless we started monitoring again and $155. Fee. Any ideas what we can Do? I feel safer just having it set than not doing anything
You can disconnect the battery inside the beige metal alarm cabinet and then unplug the wall transformer that provides power to the system to fully power it down if you aren't using it and don't want to be bothered by any beeping. It's hard to say what might be going on with the sensor but a new battery may certainly help.
Are you able to email us a picture of the system to support@alarmgrid.com?
I have an 320P1 (Vista-20PSIA) system. I've had the bF error for a long time with no issues (cellular was supposed to be disabled on my system due to the multiple problems I had with it). For the past few months the key pad has been beeping at random times and I have to enter my security code to shut it off. Front room code is now erroring on the control panel but there is nothing obstructing that sensor. Now every few days when I come home it's going off (beeping)- the past few nights I've had to get up more than once to shut it off. I checked the battery and it's dated as being changed in 2008. I'm not using the system and do not have monitoring (too many issues with the company). If I replace the battery will the continuous beeping stop? Or is there a way that I can just shut down the system on my own? I'm afraid to touch anything for fear of setting it off. Thanks for any help you can give me!
It has a number pad with buttons on the left that says off, away stay
I think you haven't completely cleared your Fire Alarm, and that you probably have a Comm Fail (because the system tried to report, but couldn't). I'm just not sure exactly what system you have, so I'm not completely sure how to tell you to clear it. Is your panel a touch screen version, or does it have a number pad with buttons on the left that say Off, Away, Stay?
the screen says Fire and Fail
Yes it does
Does it actually speak the words "Check System"? If so, it's one of the Lynx panels. Check System usually means something to do with the system as a whole, like a low battery on the panel, or a cover tamper. If you look at the display, what does it show?
I don't know what system I have but the smoke alarm when off recently, and now it keeps telling me when I arm it, Armed Stay CHECK SYSTEM. I don't know how to check system!
Yes, if you enter programming mode and press *97 followed by 1, you'll set the panel back to the default programming.
It is Honeywell Lynx plus, I have deleted all sensors to start from scratch. Is there a way to reset the panel to factory default?
What alarm system do you have? If it's a Honeywell system, it sounds like you have a fault on your zone 1. Do you know what zone 1 is for your system?
I have a "01 Fault" on my keypad, any ideas what this means or how rot get rid of it?
You can certainly try a power cycle of the panel and cellular communicator to see if the red LED goes out. If that doesn't work, you'll have to contact your alarm provider to see why the cell unit is offline.
I'm getting the bf prompt on my keypad, this is after we had a loss of power recently. This is running off cell communicator. Box w/ radio in it is showing red fault light on, and tx/rx blinking yellow intermittently. Wondering if I reboot the radio if it will reconnect to cell network? Also, if I kill power to reboot, will I set anything off? Sleeping baby.... Thanks!
Most Honeywell systems (even branded First Alerts panels) have the Auto Stay Arming feature enabled by default. This FAQ - https://www.alarmgrid.com/faq/why-does-my-lynx-touch-switch-back-to-stay-mode-when-i-arm-it-to-away-mode describes why you need to open and close an entry/exit zone after arming to away mode if you don't want the system to revert back to stay mode.
What is the issue with the Honeywell 1st Alert and attempting to arm, but it will revert back to stay mode with all devices in a ready position?
The 6150 is a Fixed English keypad. I suggest you get an alphanumeric keypad like the 6160 ( https://www.alarmgrid.com/products/honeywell-6160 ) before attempting this programming.
I have an ademco 6150 LCD keypad. The bf check will clear temporarily, if I put the chime back on, then the beeping won't stop until I clear and turn chime off. Any suggestions?And how do you get into programming? Thanks
It sounds like you have a Fixed English keypad, not an alphanumeric keypad. It is possible to disable the radio in programming with that keypad but if you mis-type an entry, you will be blind in programming and then can easily make inadvertent programming changes. If you can enter programming and want to give it a try, you would have to press * 29 followed by 0 * and then * 99 to disable the alarm communicator.
I no longer have a provider but want to use the system just for the door chimes. The bf code continues to go off. Can I by passing it?
Thanks. I will try that again.
You should contact your alarm company and ask them to tell you what is causing the error. The bF error can mean many things. It is related to your system's cellular communicator though.
Why can't I get the bf to clear out? I have entered my code and off multiple times. Any ideas? I have the ATT cellular only.
You need to have them set the GSM fault time to 0 minutes so that it doesn't sound the trouble beeping at the panel. Let us know if you need further assistance.
I live in a rural area where cell coverage is spotty. My Honeywell alarm has been sending me an alert every night, in the middle of the night, when the signal temporarily drops. It is a rapid beeping that will not stop until I hit a button on the panel. Our long range radio is just a backup, intended to be there if the land line is disabled, and the signal issues are normal - we have the same issues with our Verizon cell phones. Please, please, please - anyone who knows this stuff, how do I disable the rapid beeping? I have resorted to sleeping in earplugs, because our alarm tech is clueless. Please be my hero and tell me how to fix this. Thank you in advance!
You can only silence it if the issue is resolved so you first need to determine why your panel is showing the bF error before you can get it to silence.
If it continues to go off, how do you silence it?

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