05·RB-INT
Runbook — Internet down
Follow the signal from the street to your phone. Ninety percent of the time the answer is one of the first two boxes.
956 N Noble Loop · Showing Edition · Rev A · Aug 2026
The internet in this house arrives on fiber and is distributed by professional UniFi equipment that mostly runs for years untouched. So when it stops, the cause is usually outside your walls — or it is one specific box. Work along the chain in order and you will find it without guessing.
The chain, in one line
Street fiber → ONT (the fiber box) → UniFi gateway → PoE switches → access points → your phone. Every fault is at one link. Test from the street end inwards and you never troubleshoot the same thing twice.
First, check — in this order
- Is it everything, or just you? Try a second device on WiFi, and a wired device if there is one. One phone failing is a phone problem: turn WiFi off and on, then forget the network and rejoin. Everything failing is a house problem — carry on.
- Is it WiFi, or is it the internet? If your phone still shows the house WiFi with full bars but nothing loads, the WiFi is fine and the internet feed is not. If the WiFi network has vanished entirely, the problem is further back — power or the access points.
- Go to the closet. All the core gear lives in the second-office/bedroom closet. Look at it before you touch it, and take a photo of the cabling while you are there.
- Look at the ONT — the fiber box. This is the provider’s device, where the fiber from the street terminates. A red, amber, or flashing alarm light means the fault is on the provider’s side of the wall: nothing you do inside the house will fix it. Call the internet provider. Normal, steady lights mean the fiber is fine and the problem is downstream.
- Look at the UniFi gateway. Lights on and normal? Then the gateway is alive. Dark, or an unusual color, is your answer.
- Look at the switches and access points. The switch ports light up per connected device; each access point has a status light. One dark access point explains bad WiFi in one part of the house and nothing else.
- Only now, power-cycle — in order. Unplug the ONT, wait two minutes, plug it back in and give it two more minutes to sync with the provider. If that does not do it, power-cycle the gateway, wait for it to come fully up, then the switches. Access points come back on their own; they are powered over their network cables and have no plugs of their own.
- Wait. After a full power-cycle, give the network a genuine five minutes before declaring it broken. The gateway boots, then the switches, then every access point re-adopts. It is not instant and it is not stuck.
Do not factory-reset anything
There is a recessed reset button on every UniFi device. Holding it wipes the configuration this house runs on — the WiFi networks, the port assignments, the PoE settings — and you will be rebuilding by hand at the worst possible moment. Unplugging and replugging is safe. Resetting is a deliberate ownership-transfer step, covered on the Network page and the account transfer runbook. It is never a troubleshooting step.
Symptom → cause → fix
| Symptom | Likely cause | Fix |
|---|---|---|
| No internet anywhere; ONT shows an alarm or red light | Provider outage or a cut/failed fiber. | Call the internet provider and report it. Check their outage page or app from cellular data. Nothing inside the house will help. |
| No internet anywhere; ONT looks normal; gateway lights normal | Usually the provider’s side anyway, occasionally the gateway. | Power-cycle the ONT first, then the gateway. Still down after both and a five-minute wait → call the provider; if they confirm service is fine, it is a gateway issue (see below). |
| No internet anywhere; gateway dark or no lights | Lost power, failed power supply, or a dead gateway. | Check the plug and the outlet (test the outlet with something else — and see breaker trips). If the outlet is live and the gateway stays dark, the hardware has failed: this is a network professional’s job, and a replacement is a same-day fix for someone who knows UniFi. |
| WiFi network name has disappeared everywhere | All access points are down — which usually means the switch feeding them is down. | Check the switch: lights on? Cables seated? A dark switch is a power problem. A lit switch with dark access points is a PoE problem — see the Network page’s deep dive. |
| WiFi is fine in most of the house, dead or terrible in one area | One access point offline. | Find the nearest access point and check its light. If it is dark with the cable seated, its switch port or PoE has failed. Everything else keeps working — this is not urgent. |
| Internet works on wired devices, not on WiFi | Access-point or WiFi-config issue, not an internet issue. | Confirm on a second phone. Power-cycle the switch feeding the access points. Then use the UniFi app to see which access points are online. |
| Everything is slow rather than dead | Provider congestion, a big upload/download running, or a single device saturating the link. | Open the UniFi app and look at which client is using the bandwidth. Run a speed test from the app — it tests the house’s connection, not your phone’s WiFi. |
| Internet is down and so is the power | The house is on battery; the provider’s street equipment may not be. | Your gear stays powered by the Powerwalls, but the fiber network in the street can still be down. See power outage; expect the internet to return when the grid does. |
| Cameras, doorbell, thermostat, or locks show offline | They depend on this network. | Fix the network first — they will come back on their own. If only one device is offline while the network is healthy, power-cycle that device. |
Before you call the provider
Have three things ready: the account name and address, whether the ONT lights are normal or alarmed, and whether you have already power-cycled it. That turns a twenty-minute script into a two-minute call. Internet provider and account details to confirm at the walkthrough — they will be recorded on the Network page and the credentials sheet.
Owner's edition
Full details in the owner's edition — serial numbers, configuration and identity details continue in the complete manual, handed to the buyer at closing.
Stop and call a pro when…
- The ONT is alarmed, or the provider confirms an outage — the internet provider. This is the most common outcome and it is not a house problem.
- The gateway or a switch is dead with a live outlet — a network professional (any IT contractor who works with UniFi). Ubiquiti gear is standard and widely serviced; do not let anyone talk you into replacing the whole system for one failed box.
- A network cable is damaged, or a wall port stopped working — a low-voltage/structured-cabling contractor. The house is wired throughout; a re-termination is a small job.
- You are tempted to reset anything to factory defaults — stop, and call a network professional instead. That decision is much easier to make than to undo.
Related pages
- Network & Connectivity — the topology, the equipment list, how to change the WiFi name or password, and the deeper troubleshooting table. This runbook is the “it is 10pm and nothing works” version; that page is the reference.
- Power outage — the network stays up on battery, but the street may not.
- Smart-home account transfer — taking ownership of the UniFi console, and why to change the WiFi password last.
- Ubiquiti — Help Center
Official UniFi documentation, firmware, and app downloads. - Ubiquiti — Community forum
Genuinely useful for model-specific behavior and light codes. - Internet provider support page
to confirm at walkthrough — provider, account number, support line, and outage page go here.