If your home security system is showing FC on the display this means that your security system is having difficulties communicating its signals back to the monitoring station. In most cases FC is found on Honeywell and ADT security systems that are communicating via phone or VOIP line's. If you know your system communicates to the central station using either of these communication paths you should attempt the following.

1) Check to make sure that your phone or VOIP line is actually connected to the security system and that a wire has not been disconnected.  

2) Make sure that the phone or VOIP line connected to the system has a dial tone.

- If you find that there is no dial tone on your phone or VOIP line that most likely means that your security system is no longer working correctly and it is vital that you contact your phone/VOIP service provider and have them make sure that there is an active phone line running into the security system itself. Once the phone/VOIP line has been reestablished the security system will clear FC from your keypad automatically.

- If there is a dial tone you will want to contact your alarm monitoring company to schedule either a remote tech appointment or a onsite technical appointment if available to check your security system's tip and ring terminals to see if they are generating the necessary power to communicate alarm signals. 

*Through this process it is a good idea to contact your alarm monitoring company to notify them of your difficulties and once the system is back up and running you should test your security system to make sure that the monitoring company is again receiving alarm signals from the system.