Family-owned alarm company in Potomac, MD since 1984
Home Alarm Systems and Monitoring for Montgomery County Homeowners
Potomac Security Systems installs, monitors, and services home security systems in Potomac, Bethesda, Chevy Chase, Rockville, Silver Spring, and throughout Montgomery County, Maryland. You talk to the same family that installs your system, and we recommend only what your home needs.
Most of our new customers call because a neighbor or a family member recommended us.
What We Do
Home Alarm Systems
Honeywell alarm systems with door and window sensors, motion detectors, glass-break sensors, and smoke, carbon monoxide, and water leak alerts.
See monitoring plansCameras and Video Doorbells
See who is at the door, watch the driveway or backyard from your phone, and review recorded motion events. We add cameras to existing systems too.
Ask about camerasControl From Your Phone
Arm and disarm, get alerts, and check locks, lights, and cameras with the Total Connect app. We set it up with you and stay available when you get a new phone.
Compare plans with the app24/7 Alarm Monitoring
Cellular monitoring that does not depend on a landline or internet connection, with an optional two-way voice add-on so the monitoring station can speak with you during an alarm.
Monitoring from $26 a monthAreas We Serve
We serve homes and small businesses throughout Montgomery County, Maryland, including:
Already Have an Alarm System?
Moving into a home we installed
Many Montgomery County homes already have one of our systems. Call us with the address. New owners who continue monitoring get a free visit to enter their own codes, learn the system, and register it with the county.
Switching from a national alarm company
We install Honeywell equipment, and we can often reuse your existing wiring and door and window contacts. The panel and communicator usually need replacing. A free on-site estimate tells you exactly what can stay.
Losing your landline
Verizon is retiring copper phone lines across Montgomery County. If your alarm still dials out over a landline, we can upgrade it to cellular monitoring so it keeps working.
What To Expect
Call for a consultation
We discuss your home, priorities, and budget, then schedule a free estimate at your house.
Receive a clear estimate
We explain your options in plain language and recommend the system that fits your home, without packages you do not need.
Installation and ongoing service
Your system is installed cleanly and tested with you. Afterward you call the same office for service, battery help, and app questions.
Frequently Asked Questions
These are the questions we answer most often by phone and email, with the same answers we give our customers.
Before you buy
Do you only serve Potomac?
We are based in Potomac and install and service alarm systems throughout Montgomery County, Maryland. We do not install in the District.
What does a free estimate involve?
Jeff comes to your home, walks through it with you, and follows up with a written proposal. There is no charge and no obligation. A wireless system does not have to be installed all at once; sensors you add later cost the same as they would have on day one.
Can you take over a system installed by another company?
We install and service Honeywell equipment only, but we can often reuse existing wiring and door and window contacts. The panel usually needs replacing, and any older 3G or 4G communicator must be upgraded to LTE before it can be monitored. A free evaluation tells you exactly what can stay.
Do I need a landline?
No. Our systems report through a cellular radio communicator, which does not need a phone line or your internet and sends signals faster than a landline. Keeping a landline as a backup is optional.
Is there a long contract?
Monitoring has a one-year term and then continues month to month. We do not use proprietary programming, so after the first year you are free to switch and another dealer can program your system for their monitoring. If you prepaid a quarter and cancel, we refund or prorate the unused portion.
Can I control the system from my phone?
Yes, with the Total Connect service on the cellular plans. You can arm and disarm, see the activity log, get alerts, and view cameras, which house sitters find much easier. Without Total Connect the system is controlled from the keypad only.
Do you install cameras and video doorbells?
Yes. Cameras and video doorbells work through the Total Connect app over your home Wi-Fi and can be added to an existing system. Recorded clips are kept with the optional video storage add-on.
What about fire, carbon monoxide, and water?
Monitored smoke, carbon monoxide, heat, and water sensors can be added to any system, and monitored smoke detectors keep working on the panel battery during a power outage. Every keypad also has fire, police, and medical buttons that send an emergency signal straight to the monitoring station.
Can you send an alarm certificate for my insurance company?
Yes. Insurers often ask for a dated certificate showing the system is monitored. Email us and we will send the certificate from the monitoring station, which lists your installation date, monitored smoke or water sensors, and remote services.
Do I need to register my alarm with the county?
Yes. Montgomery County Police require every monitored alarm to be registered, and a new system goes through a seven-day test period before police are dispatched. We handle the test period and the paperwork with you.
For current customers
My keypad is beeping or says low battery. What should I do?
The keypad tells you whether it is a sensor battery or the system battery. Sensor batteries are common hardware-store sizes (CR123 in motion and glass-break detectors, CR2032 in door and window sensors). You can silence the beep with your code and still arm the system. Call us and we will walk you through it, or come out. Batteries we install are covered for a year.
The keypad says trouble or communication failure.
Cell towers occasionally go down and restore themselves. Enter your code a few times to see if the message clears, or unplug and replug the communicator to reboot it. If a power outage preceded it, check the outlet the transformer is plugged into. If it persists, call us.
How are alarm events handled?
If you disarm within about thirty seconds, nothing happens. Otherwise the monitoring station calls the two premise numbers on file, which Montgomery County requires before dispatch. If no one answers, it dispatches the authorities and then calls your call list. Panic buttons dispatch immediately without a call.
How do I change codes, phone numbers, or add a house sitter?
Email or call the office. We make the change with the monitoring station and confirm it back to you. For a trip, tell us the sitter's name and passcode and we will add them to your call list for those dates.
We are renovating or replacing doors and windows. What about the sensors?
Wireless sensors are held on with double-sided tape, so you or your window installer can pry them off and set them aside, and we will reinstall them. For hardwired sensors, ask the installer to save the wires. During the work we can put the system on test or give the contractor a temporary code so there are no false alarms.
My camera shows offline after I changed my Wi-Fi.
Cameras need power and your Wi-Fi. Check the outlet first, then the app's Wi-Fi settings. A new router or password means the cameras must be re-enrolled, which is usually a short visit. Alarm signals themselves travel over the cellular radio, not Wi-Fi.
We are selling our home. What happens to the system?
Email us the closing date. We cancel monitoring that day, put the system on test so there are no false alarms, and send a prorated final invoice or refund. If the buyer wants to keep the system, Jeff comes out at no charge to enter their codes, explain the system, and register it with the county.
What is covered by the warranty?
All parts we install, including batteries, are covered for one year. Parts and batteries we replace during a service call are covered for another year. An optional extended warranty waives the service-call charge for battery changes and replaces defective devices at no charge.
Can I get a new yard sign or window stickers?
Yes, they are free. Stickers go in the mail. Yard signs are expensive to ship because of their shape, so we drop one off when we are nearby or leave one on our porch for pickup.
How do I pay online?
Go to potomacalarms.com and click Sign In at the top right. If you have not set a password yet, ask us for a registration link. You can pay by card or bank account and turn on automatic payments, which run once a quarter when the invoice is issued.