CCTV Goes Offline When It Rains
Water, Voltage Drop & Surge (2026)

What rain actually does to a camera system

Rain does not damage a camera by falling on it. Outdoor cameras are sold with a weather rating for the housing, and the housing is almost never the thing that fails. What rain does is find every joint, gland and screw hole that someone made after the camera left the factory, and it finds them in a very specific way: not by pouring in from above, but by wicking along the outside of a cable, sitting in the bottom of a junction box, and creeping into a connector by capillary action over weeks. That is why the fault is intermittent, why it gets worse each monsoon, and why it clears up for a few dry days and comes back.

There is a second mechanism that is easy to miss. Wet cable and damp connectors lower the resistance between the conductors inside the cable. On a Power over Ethernet run that carries both power and data, a small leakage current between pairs is enough to corrupt the data long before anything looks visibly wet, so the camera stays powered up and the recorder still shows the channel as offline. A technician looking only for a puddle will walk past that fault.

And a third: rain in the Klang Valley arrives with lightning, and a nearby strike puts a surge onto the mains and onto every long metal run in the building. That damage is permanent and it looks nothing like a water fault, which is why it is worth ruling in or out early. It is covered in full in CCTV lightning and surge protection.

First question: one camera, or all of them?

This single question splits the diagnosis in half and costs nothing to answer, so answer it before anything else. Watch the recorder or the app during the next shower and note exactly what goes.

• One camera drops, the rest stay up. The fault is on that camera’s own run: its joint, its gland, its connector, or the length of its cable. Nothing shared is involved.
• Several cameras on the same side of the building drop. Look for one shared thing — a common junction box, a switch in a wet position, an external route where the cables run together.
• Everything drops at once, including the app. That is the recorder, its power supply, or the internet connection — not the cameras. Check whether the recorder itself is still running.
• Everything drops but the recorder is still recording. The cameras are fine and the recorder is fine; you have lost the internet, which is a different problem with a different owner.
• Nothing drops but the images are milky or hazed. That is moisture or condensation inside the camera dome, not a network fault at all.

Write the answer down with the date and the weather. Two observations across two storms are worth more than an hour of guessing, and any competent technician will ask you for exactly this.

Symptom, likely cause, and what to check first

Water at the gland and the junction box

The gland is the fitting where the cable enters the camera or a junction box, and it is the most common failure point on a Malaysian install for a simple reason: it is the one part of the assembly the installer makes on site, in the heat, at the top of a ladder, at the end of the day. Three things go wrong with it.

The gland is not tightened onto the cable jacket, so it grips nothing and the cable can move; water follows the cable straight in. The box is mounted with the entry pointing up, which turns it into a cup — rainwater running down the wall collects at the entry and sits there. And there is no drip loop: the cable runs downhill directly into the fitting, so every drop that touches the cable is delivered into the joint. A drip loop is nothing more than a deliberate sag in the cable below the entry point, so water runs to the bottom of the loop and falls off. It costs nothing, it takes seconds, and its absence is visible from the ground.

The related myth worth killing: a camera marked with a weather rating is rated for its own housing, as it left the factory. It says nothing about the joint you made in its cable, the box you screwed to the wall, or the hole you drilled through the render. Those are your installer’s work and they carry no rating at all unless the parts used were chosen for outdoor use.

The outdoor cable joint, and why it is the weak point

On most jobs the camera arrives with a short pigtail lead that has to be joined to the cable running back to the recorder. That joint is the single most abused detail in the trade. Done properly it lives inside a weatherproof box that is sealed, mounted with the entry downwards, and positioned where a person can reach it again. Done badly it is two connectors pushed together and wrapped in ordinary electrical tape, taped to the underside of an eave, and completely inaccessible.

Ordinary PVC tape is not a seal. It unwinds in the heat, its adhesive creeps, and within a couple of wet seasons it is holding water against the connector rather than keeping it out. The materials that do work — a proper weatherproof enclosure, a gel-filled or otherwise water-blocked connector, self-amalgamating tape that fuses into a single mass — cost very little more, and the difference only becomes visible in year three, which is exactly why cheap jobs skip them.

Position matters as much as materials. A joint that has to be reached from a ladder over a driveway, in the rain, is a joint that will not be inspected until it fails twice. Ask where every outdoor joint is before the crew leaves, and photograph them.

PoE voltage drop: the fault that only looks like rain

Power over Ethernet sends the camera’s power down the same cable that carries its video. Over a long run, through thin conductors, some of that voltage is lost as heat in the cable itself, and the camera at the far end receives less than it should. On a dry afternoon it copes. At night, when the infrared illuminators switch on and the camera’s current draw goes up, it may not — and the camera reboots, comes back, and reboots again.

Rain enters the story in two ways. Damp in a connector adds resistance, which subtracts a little more voltage from an already marginal run. And rain arrives with darkness and cloud, which is exactly when the infrared comes on. So a marginal PoE run behaves like a water fault: it fails during storms and works in the sun. The tell is the pattern — a water fault stays down until things dry out, whereas a voltage-drop fault cycles: down, up, down, up, minute after minute.

The causes are cable length, cable quality and joints. Copper-clad aluminium cable sold as network cable has noticeably higher resistance than solid copper and is the commonest reason a run that should have been fine is not. That is a decision made at quoting time, which is why cable specification belongs in the written quote — see CCTV wiring, concealed versus surface.

Telling a power fault from a network fault

The last row of that table is the most useful test on the list, and it is the one nobody does: take the camera down, carry it to the recorder, and connect it with a short patch lead. If it works perfectly there, the camera is fine and the problem is somewhere in the run — cable, joints or connectors. If it misbehaves there too, the camera is the problem and no amount of re-taping a joint will help.

A ten-minute diagnostic sequence

1. Look at the recorder itself. Is it powered and recording? If not, the cameras are innocent — check the socket, the adaptor and the circuit breaker.
2. Count what is down. One channel, a group, or everything. Write it down with the time and the weather.
3. Look for infrared. In the dark, a working camera’s illuminators show as a faint red glow. Glowing but offline means data; dark and offline means power.
4. Swap the recorder port. Move that camera’s cable to a port you know works. If the fault moves with the cable, the port is fine.
5. Bench-test the camera. Short lead, straight into the recorder. This separates the camera from the run in one step.
6. Inspect the joint. Only now go up the ladder. Open the junction box and look for standing water, green corrosion on the pins, and a gland that is not gripping the jacket.
7. Check the run for damage. Follow the cable for staples through the jacket, a kink at a corner, and any point where it has been dragged over a sharp edge.
8. Consider surge. If the camera and the recorder’s port for that channel both died in the same thunderstorm and neither has recovered, you are not looking at water.

Steps one to five need no tools and no ladder. Most homeowners can complete them in ten minutes and hand a technician a diagnosis instead of a symptom, which usually turns two visits into one.

When it is not water at all

Water faults recover. Surge faults do not. If a channel has been dead since a thunderstorm and has never come back, if the recorder’s network port for that channel is also dead, or if a network switch in the chain has stopped passing traffic entirely, the cause is electrical rather than wet. The camera cable is a long conductor running outside the building, and a nearby strike induces a voltage on it that arrives at both ends. Sealing the joint will not bring it back.

The distinction matters commercially too: a water fault is a workmanship issue and often a warranty conversation, while surge damage is an act of weather that proper protection reduces but never eliminates. The protection options, and their honest limits, are set out in CCTV lightning and surge protection. Whole-premises protection and earthing sit with an electrician — see lightning and surge arrester installation.

Wireless and 4G cameras in a downpour

Wireless cameras fail in rain for entirely different reasons, and swapping a wired camera for a wireless one to “solve” a rain fault usually trades one problem for another. Heavy rain attenuates a radio signal, wet foliage between the camera and the router absorbs more of it, and a camera that was marginal in the dry becomes unusable in a storm. Battery cameras also charge less in overcast weather if they are solar-assisted, so a week of rain can flatten one that survives the dry season easily.

The consolation is that a wireless camera has no long outdoor cable to carry a surge, which genuinely reduces one failure mode. The comparison is set out in Wi-Fi cameras versus professional CCTV, and the mains-free and broadband-free options are covered in CCTV without Wi-Fi, using 4G or solar.

What the repair actually involves

A water-ingress repair is not a re-tape. Done properly it means opening the joint, cutting back the cable past the wet and corroded section — corrosion travels up the conductors, so the visibly green part is not the whole of it — remaking the termination on clean copper, and re-housing it in a weatherproof enclosure mounted with the entry downwards and a drip loop below it. Where the cable itself has taken water along its length, the honest answer is a new cable, because a wicked run will keep failing however well the ends are made off.

If the camera has water inside the housing, the dome gasket and the body seals get inspected, and a camera that has been full of water more than once is usually replaced rather than dried out. And if a channel is dead from surge, the repair is replacement of whatever the surge destroyed, plus a conversation about protecting the replacement.

What it costs to get someone out

These are market figures published by others rather than by ClickBina (market estimate 2026, indicative Klang Valley). Read them carefully: the maintenance rows come from one published Klang Valley rate card, and the two per-camera rows from a second single operator’s card, so every figure here is one installer’s price rather than a surveyed market rate.

Two things move the bill more than the visit itself. The first is whether the cable has to be re-pulled, which turns a joint repair into a cabling job at the per-point rates in the wiring guide. The second is access — a joint under a two-storey eave over a driveway needs equipment, and that is a separate line. Whole-system pricing, and what a new install should itemise, is on the CCTV installation cost guide. We do not publish a package price for this work; we survey, then quote.

Preventing the next monsoon

• Every outdoor joint in a proper enclosure, sealed, entry pointing down, in a position a person can actually reach again.
• A drip loop below every entry. Free, instant, and the single highest-value habit on the list.
• Mount under an eave or overhang where you can. A camera that never takes direct rain never tests its seals.
• Solid copper cable of the right category, so the run has voltage headroom on a wet night rather than sitting on the edge of failure.
• Spare cable at both ends. A metre of slack means the next repair cuts back and remakes rather than re-pulling the whole run.
• An annual pre-monsoon check. Open the joints, look for water and corrosion, re-seal what needs it, and confirm every channel at night as well as by day.
• Photograph everything before the lids go on, so the next technician does not have to find your joints by feel.

What to ask before the technician leaves

1. Which fault did you actually find — water, voltage, or surge? Show me.
2. Did you cut back to clean copper, or re-use the existing termination?
3. What enclosure and connector did you use, and is it rated for outdoor use?
4. Is there a drip loop now, and is the entry pointing down?
5. Is this cable run within a sensible length for the camera at the end of it, or is it marginal?
6. What is the warranty on this repair, and what happens if it fails in the next storm?
7. Which other joints did you inspect while you were up there, and what condition were they in?
8. Photograph each repaired joint and send them to me.

Why ClickBina

ClickBina services and repairs camera systems across Kuala Lumpur and Selangor, and rain faults are among the most common calls we take. We diagnose before we quote: we want to know whether one camera dropped or all of them, whether the infrared was still on, and what the weather was doing, because those three answers usually locate the fault before anyone climbs anything. We will tell you plainly when a joint can be remade and when a cable has to be re-pulled — and we do not publish a package price for security work, so every job is quoted from what the survey finds. Send photos of the camera, the joint and the recorder, or a floor plan, and we will quote after a site survey. The mains side sits with our electrical and plumbing team.