Why Does Sonoff Device Keep Going Offline at Night?
- Scheduled router reboot at night
- Router/ISP maintenance window
- 2.4GHz interference peaking at night
Problem Description
Your SONOFF device goes offline in eWeLink every night around the same time and comes back online in the morning. The device works fine during the day but consistently drops off at night. Common causes include router WiFi power-saving schedules that shut off the radio overnight, DHCP leases expiring while the device is idle, the circuit being on a switch or timer someone turns off at night, or a firmware bug that stops sending keepalive packets after extended idle periods.
Why This Happens in Real Homes
A SONOFF that reliably goes offline every night follows a schedule — the most common being a router that's set to reboot overnight, an ISP maintenance window, or a DHCP lease expiring in the small hours. Neighboring WiFi networks also get busier at night, congesting the 2.4GHz band.
Check your router for a scheduled nightly reboot and disable it, and reserve a DHCP IP with a long lease so the address doesn't expire overnight. Reduce 2.4GHz interference by moving to a clearer channel away from neighbors, improve signal at the device, and turn off any router night power-saving. Update firmware, and make sure no automation is cutting the device's power at night.
Symptoms
- Offline every night
- Drops overnight, back by day
- Nightly disconnects
- Offline at a set time
- Reconnects in the morning
- Only night drops
- Recurs daily at night
- Offline during off-hours
Recognize these? Here's what usually causes it.
Common Causes
- Scheduled router reboot at night
- Router/ISP maintenance window
- 2.4GHz interference peaking at night
- Weak signal tipping over
- Router power-saving at night
- DHCP lease expiring overnight
- Firmware issue
- Neighboring networks congesting 2.4GHz
Most fixes happen in the first 3 steps.
Do not factory reset all devices before checking router schedules.
Tools & Requirements
Step-by-Step Solution
Check for router power-saving or scheduled WiFi shutdown
Some routers have a 'WiFi scheduler' or 'green mode' that turns off the WiFi radio at night to save power. If your SONOFF device goes offline at the same time every night (e.g., midnight to 6 AM): check your router settings for a WiFi schedule. Also check: some ISP-provided routers disable 2.4GHz at night if no devices were actively using it — SONOFF devices maintain a persistent connection but may not generate enough traffic to keep the radio active on power-saving routers.
Check for DHCP lease expiration
If your router's DHCP lease time is short (1-4 hours), the SONOFF device's IP lease expires overnight. Most devices renew the lease automatically, but some older SONOFF firmware (BASICR2, TH10/TH16) had a bug where the DHCP renewal failed silently, leaving the device without a valid IP until reboot. Fix: set your router's DHCP lease time to 24 hours or longer. Or assign a static IP / DHCP reservation for each SONOFF device using its MAC address (found in eWeLink > device > ··· > Device Info).
Check if the device is on a switched outlet or circuit
If someone turns off a light switch, power strip, or circuit breaker at night: any SONOFF device on that circuit loses power. In the morning when the switch is turned back on, the device reboots and reconnects. Check the physical circuit the SONOFF device is plugged into. For in-wall MINIR4 installations: check if the breaker is on a timer or if another household member is turning off the breaker at night. The device cannot go offline and come back online on its own without losing and regaining power or WiFi.
Check WiFi signal at the device location at night
WiFi signal can change at night due to environmental factors: metal shutters being closed, humidity changes, or neighboring WiFi networks increasing power. Use a WiFi analyzer app on your phone at the device's location to check 2.4GHz signal strength during the time the device goes offline. If the signal drops below -80 dBm: the device loses connection. Add a WiFi mesh node or repeater closer to the device. Also check if a neighboring WiFi network switches to a conflicting channel at night.
Update the device firmware
SONOFF has fixed WiFi keepalive bugs in firmware updates for several models. The BASICR4 firmware v1.4.0 fixed a bug where the device stopped sending keepalive packets after 6+ hours of idle operation, causing the cloud server to mark it as offline. In eWeLink, check for firmware updates: device > ··· > Firmware Update. If the device is already on the latest firmware and still goes offline nightly: enable eWeLink LAN control as a supplementary connection path, and consider replacing the device if it is an older model (BASICR2 or original BASIC).
Quick Solutions
Still having issues? This is usually the deeper cause below.
This usually happens right after a router reboot or ISP change — the device rejoins the network but drops its cloud session silently.
Nighttime pattern usually indicates infrastructure policy, not random device failure.
Most WiFi drop-offs happen right after a router reboot or ISP swap — the device reconnects to the network but silently loses its cloud registration.
- Scheduled router reboot at night
- Router/ISP maintenance window
- 2.4GHz interference peaking at night
- Weak signal tipping over
- Router power-saving at night
Before you go — try one of these (they fix most cases).
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Official Manufacturer Manual
SONOFF provides official product documentation through their online manual rather than downloadable PDF. Access setup guides, troubleshooting steps, and product specifications for your Sonoff Nighttime Dropouts.
Source: sonoff.tech
Need More Help? SONOFF Support
Note: The contact information below connects you directly to SONOFF's official customer support team, not Trunetto. They can help with warranty claims, device replacements, and advanced technical issues.
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