When the intercom dies, the whole entrance turns awkward. Guests stand at the gate, couriers leave without their parcel, and the household falls back on shouting over the wall or handing out keypad codes. We repair intercoms across Pretoria and Centurion every week — on homes, complexes and small business entrances — and the same handful of faults account for most call-outs. This guide is the diagnosis list we work through on site: what each symptom usually means, which checks are genuinely safe to do yourself, and when the fault needs a technician with test gear.
First, Rule Out the Free Fixes
Before assuming the worst, work through the checks that cost nothing:
- Power. Most dead intercoms are simply unpowered. Check the plug-in adapter (it works loose or gets borrowed), the transformer if the system is hard-wired, and whether the circuit it feeds tripped — often after a storm. If the keypad and gate motor are also dead, the shared supply is the suspect, not the intercom.
- The handset. Confirm the ringer switch is on and the volume is up. On cordless-style handsets, check or replace the batteries. Reseat the handset firmly on its cradle — charging contacts that look fine can still be tarnished.
- The gate itself. If the gate still opens from the remote and keypad, the motor and lock are fine and the fault lives in the intercom path. If the remote is also behaving oddly, start with our remote troubleshooting guide instead — the two share RF and battery causes.
- Load shedding aftermath. An adapter plugged into a non-essential circuit stays dead through every outage stage and sometimes fails to come back cleanly afterwards. Test the socket with another appliance.
What Each Symptom Usually Means
| Symptom | Most likely cause | Typical fix |
|---|---|---|
| Nothing rings anywhere | No power: adapter, transformer or tripped supply | Restore power; technician if the supply tests fine |
| You answer but hear nothing | Door-station microphone blocked, wet or failed | Open and dry the door station; replace if corroded |
| Visitor audible, you are not | Handset hookswitch or speaker fault | Check handset seating; technician for handset repair |
| Speech fine, gate will not release | Release button, relay or lock wiring — a separate circuit from audio | Technician: relay and lock circuit diagnosis |
| Crackle and dropouts | Corroded joint, water ingress or damaged cable | Inspect junctions and the gate cable run |
| Video screen dark, audio works | Screen power feed or camera failure | Technician; screen swap is the common outcome |
The Classic Culprit: the Cable Across the Moving Gate
On wired gate intercoms, the single most common fault we find is also the least obvious: the cable that crosses from the fixed pillar onto the moving gate leaf. That loop flexes every single open-and-close cycle, thousands of times a year, until the copper inside fatigues and fractures — while the insulation still looks perfectly intact. The symptoms start exactly as intermittent crackle and dead days, then the system goes silent for good. Water sitting in that cable loop at the pillar makes it worse. Repairing it properly means running a new section through conduit with a proper service loop, which is technician work, not a tape-and-hope job.
Wireless and App Intercoms Fail Differently
Wireless and smartphone intercoms trade wiring faults for different ones. Wireless units suffer flat batteries, range problems through walls, and the same RF congestion that plagues remotes near inverters and backup power systems. App-based GSM intercoms bring their own distinctly South African fault: the prepaid SIM inside runs out of airtime or data and the system silently stops calling — no error, no beep, just a gate that never rings. If your app intercom "stopped working", check the SIM's airtime and data balance first; it is the intercom equivalent of a flat remote battery. Router reboots after load shedding and lapsed cloud accounts round out the list.
Water, Weather and Lightning
Door stations live outdoors, pointed at the weather. Condensation inside a surface-mounted unit muffles speech long before the electronics actually fail, and standing water finishes the job. Mounting under a small canopy, keeping the drainage slots open, and drying a wet unit before blaming it solves a surprising share of "dead" intercoms — the same after-storm inspection habits our storm season prep guide recommends for the rest of the entrance. And when lightning is involved, the intercom is often collateral damage: its electronics sit right in the surge path from the gate. The surge protection guide explains why a small device at the board is cheaper than a board, a handset and a door station.
Load Shedding and the Silent Intercom
An intercom that only works when Eskom does is an intercom on the wrong circuit. Hard-wired systems fed from a non-essential supply go dark through every outage, right when you most want to see who is at the gate. Moving the feed onto an essentials circuit or the backup supply is usually straightforward while a technician is on site; our load shedding backup guide covers how the entrance's power is typically split. GSM units need network coverage as well as power, so test them on a phone before blaming the hardware.
Fix It or Replace It?
Age and parts decide this one. If the pillar station and cable run are sound, a replacement handset is usually inexpensive and the system lives on. Old audio-only systems with discontinued handsets are the borderline: once the door station itself fails and no parts exist, repairing stops making sense and a modern replacement — often with video and app access you were going to want anyway — becomes the better spend. Our intercom buying guide covers that choice properly. Either way, the diagnosis comes first: the fault table above resolves most systems to a culprit before any money is spent, and the error code guide helps when the fault turns out to live in the gate motor's electronics instead. For prevention, a quick visual check of the door station, handset contacts and cable loop belongs in the routine our maintenance checklist already covers for the rest of the entrance — and gnawed cabling found there is a job for the pest damage guide.
Diagnose in order: power first, then the cable across the moving gate, then the electronics. Most faults die at the first two. When the remainder point to relays, boards or a cable re-run, that is the technician's half of the job — and the half we do every day.
Frequently Asked Questions
Why does my intercom ring but the gate does not open?
The audio path and the release path are separate circuits. Speech working means the intercom itself has power; the fault is usually the release button, its relay, or the wiring to the lock or motor. A technician can confirm which with a meter in minutes.
Can a faulty intercom stop my gate from opening?
On systems where the intercom triggers the release, yes, but the motor and remote usually still work. If nothing on the entrance responds at once, suspect the shared power supply rather than the intercom itself.
How much does intercom repair cost in South Africa?
It depends entirely on the fault: a handset battery or a dried-out door station is minor, while a cable re-run or a replacement system costs more. An honest quote follows an inspection, because the symptom rarely reveals the cause on its own.
Is it worth repairing an old intercom system?
If the door station and cabling are healthy and a matching handset is available, repair is usually worthwhile. If the system is a discontinued audio-only model with no parts, replacement with a modern video or app system is the better long-term spend.