Motion sensor triggers on nothing
Heating or cooling airflow moving a sign, a plant or a balloon, or a sensor aimed at a heat source. Repositioning it is normally the entire fix.
Security & Low Voltage4,401 businesses licensed for it
Alarm system repair
An alarm that cries wolf gets switched off, and an alarm that is switched off is not an alarm. Work covers panels that will not arm, faulty and drifting sensors, door and window contacts, sirens and strobes, communication paths to the monitoring center, and battery and power supply failures. Repeated false alarms also carry a direct cost in most cities, where the police department bills for repeat responses.
Enter your ZIP to see the businesses listed for this trade nearest to your site, with their phone numbers.
- Free to searchno account, nothing to submit
- Public registersevery listing names its source
- License numberswhere the state publishes one
- Directyou call the business yourself
- Our estimate
- $180-$4,500
- Time on site
- 1.5-8 hrs
- Fault patterns covered
- 2
- Licensed for this trade itself
- 4,401
What alarm system repair costs
Most of these jobs land near $440. The full spread runs $180 to $4,500, and the gap between those two ends is diagnosis against replacement rather than one business being dearer than another.
What moves it: how much of the job is parts, whether the fault is found in the first hour or the third, access to the equipment, and the hour of the day you call. We never speak to the businesses listed here, so there is no rate card behind any of this. It is our own band for the category, and there is no regional index: the figure does not change with your metro.
| How soon you need it | Typical | Range |
|---|---|---|
| Scheduled visitBooked in advance, no urgency multiplier applied | $440 | $180 to $4,500 |
| Same dayOur band multiplied by 1.12 | $495 | $200 to $5,040 |
| Emergency calloutOur band multiplied by 1.35 | $595 | $245 to $6,075 |
Our estimate from national cost bands, not a quote from any business. Every row is the same band with the urgency multiplier the site applies everywhere else, so this table can never contradict the headline number. Ask for a written price before the work starts.
Who is licensed to do this work
In California the classification that squarely covers this is C-7 low voltage systems, and the register says who holds it. Every listing on this site shows the classification, the license number and the date we read it, with a link back to the register entry so you can check it against the state rather than against us.
Overlapping classifications exist and are labeled as overlapping rather than as a match: C-10 electrical and C-28 lock and security equipment. A general building contractor may hold the job and subcontract the trade, which is a real answer and a different one, so the card says which of the two you are looking at.
One thing worth being plain about: CSLB classifications do not distinguish commercial work from residential. There is no separate commercial license to hold and no register field that would prove one. That is why this page describes the equipment rather than the contractor, and why nothing here says a business has been checked out. We read a public record on a stated date. That is the whole claim.
Before you pay for a callout
Two minutes of checks that sometimes end the problem
We would rather you did not need a callout at all. These are the checks that end the most calls for this fault.
Try a quick fix first
Some issues resolve without a truck roll. Two minutes now can save the callout.
- 1
Write down which zone triggers and at what time of day. False alarms almost always have a pattern, and the pattern usually names the cause: a heater cycling, a delivery, a sign swinging in front of a sensor.
- 2
Check for a low battery message. A dying backup battery causes a lot of unexplained panel behavior and it is the cheapest part in the system.
- 3
Ask your monitoring company to confirm they are receiving signals. A system that arms correctly but never reports is the failure mode nobody notices.
- 4
Check your city's false alarm policy. Repeat responses are billable in most places and the fees escalate quickly.
What the visit actually includes
- Event log review to find what is actually triggering
- Sensor, contact and detector testing across every zone
- Battery and power supply replacement
- Communication path test to the monitoring center
- Walk test with you present so you can see each zone confirm
Diagnosis
How alarm faults usually present
Written from how these faults actually present on a working premises, not from a manual.
System arms but monitoring never hears from it
A communication path that failed when a phone line was disconnected or an internet provider changed. It is silent and it is the reason to test the path rather than the siren.
Listed for this trade
Businesses listed for alarm
Read from public license registers, so there is no ranking here and no distance: this page has no location to measure from. Enter your ZIP to sort by who is nearest to your site.
By location
Alarm system repair near you
Local pages show which businesses are listed for that metro, how far out they sit, and the local conditions that drive demand.
Counted from the businesses we have imported for each metro center inside a 25 mile radius, and counting only those whose own license classification names this trade. General contractors licensed widely enough to take it on and subcontract it are excluded here, and still appear in a search. A metro reads “none yet” until we load a register that covers this trade there.
All coverage areasQuestions owners ask
Alarm FAQs
Short, specific answers. If yours is not here, ask the business you call before you agree to the visit.
Why does my alarm need a phone line?
Older panels report over a landline, and businesses that dropped their landline often lost monitoring without realizing. Cellular and internet paths replaced it, and a technician can confirm what yours uses in minutes.
Can I change monitoring companies and keep the equipment?
Frequently yes, if the panel is not locked to the installer. Ask specifically whether the panel is proprietary before you sign a new agreement.
Who is licensed for alarm work?
C-7 low voltage and C-28 lock and security equipment are the relevant CSLB classifications. Alarm companies in California also need a separate state alarm company license, which is a different register from this one.
Related work
Often booked in the same visit
Batching jobs into one mobilization is the cheapest way to buy this kind of work.
CamerasCameras offline, no recording, dark night images and recorders that lost the drive.from $200Access controlFailed readers, keypads, maglocks, intercoms and staff cards that stopped working.from $220Network cablingDead data points, damaged cabling, patch panels and cabling for new equipment.from $200Walk-in coolerCooler not holding temperature, iced coils, failed compressors and door seals.from $260
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Ready when you are
Need alarm sorted?
Search your ZIP to see the businesses listed for this trade nearest to your site, with the license numbers and phone numbers we hold, then call them yourself.
- Cost to search
- Free
- Account needed
- None
- Who you call
- The business