Panasonic Air Conditioner Sleep Mode

Panasonic air conditioner sleep mode is a smart feature designed to improve your rest by gradually adjusting temperature and airflow throughout the night. By automatically cooling less and maintaining a comfortable environment, it reduces energy use and minimizes disruptions. This guide explores how to use sleep mode effectively, its benefits, and why it’s ideal for light sleepers and eco-conscious homeowners.

Key Takeaways

• Saves Energy: Sleep mode reduces power consumption by lowering fan speed and temperature slightly over time, cutting electricity bills.

• Improves Sleep Quality: The gradual cooling mimics natural body temperature drops, helping you fall asleep faster and stay asleep longer.

• Automatic Temperature Adjustment: Panasonic units adjust settings based on preset schedules, eliminating manual changes during the night.

• Reduces Noise: Lower fan speeds mean quieter operation, ideal for light sleepers or bedrooms near busy streets.

• Prevents Overcooling: Avoids waking up too cold by preventing the AC from running at full blast all night.

• Easy to Activate: Most models include a dedicated sleep button or menu option in the remote control.

• Compatible with Smart Features: Some Panasonic models integrate with home automation systems for voice or app-based control.

Quick Answers to Common Questions

Can I use sleep mode on any Panasonic air conditioner?

Most inverter-based Panasonic models include sleep mode, but basic non-inverter units may not. Check your manual or look for “Sleep” or “Econavi” buttons on the remote.

Does sleep mode work during the day?

Yes, but it’s optimized for nighttime use. You can activate it anytime, though daytime sleep mode may not align with typical body rhythms.

How much energy does sleep mode save?

On average, sleep mode reduces nighttime energy use by 15–20%, depending on usage patterns and ambient conditions.

Will sleep mode keep me awake if I’m sensitive to noise?

No—sleep mode lowers fan speed significantly, producing whisper-quiet operation suitable for light sleepers.

Can I override sleep mode if needed?

Absolutely. Press the sleep button again or adjust settings manually. The AC will respond immediately.

In practice, the 15–20% savings figure assumes a properly sized inverter unit running in a well-insulated bedroom. If your AC is oversized or the room has significant air leakage, the actual savings may be closer to 8–10%. A quick way to gauge your own savings is to compare a week of nightly kWh usage with sleep mode on versus off using the Comfort Cloud app’s energy report.

📑 Table of Contents

• What Is Panasonic Air Conditioner Sleep Mode?

• How Does Sleep Mode Work?

• Benefits of Using Sleep Mode

• How to Activate and Customize Sleep Mode

• Comparing Sleep Mode to Other Panasonic Features

• Tips for Maximizing Sleep Mode Benefits

• Real-Life User Experiences

• Conclusion

• Frequently Asked Questions

What Is Panasonic Air Conditioner Sleep Mode?

When you think of a good night’s sleep, comfort plays a big role—and that includes your bedroom’s temperature. That’s where Panasonic air conditioner sleep mode comes in. It’s not just another cooling setting; it’s a thoughtfully engineered system designed to help your body cool down naturally while you drift off, then maintain that perfect balance all through the night.

Sleep mode works by slowly lowering the room temperature over a set period—usually around 15 to 30 minutes—before stabilizing at a level that supports uninterrupted sleep. Unlike standard cooling, which keeps the room at a fixed temperature, sleep mode understands that our bodies naturally drop their core temperature as we sleep. By matching this rhythm, Panasonic units help you fall asleep faster and reduce nighttime awakenings due to discomfort.

This intelligent feature is available across many Panasonic inverter air conditioners, including popular models like the CS/CU-XU series and some premium NR series units. Whether you’re using a window unit, split system, or ceiling cassette model, chances are your AC has a sleep function. And what makes it even better? It does all this without requiring constant attention—just press one button, and the unit handles the rest.

Model compatibility quick reference: Most CS/CU-XU, CS/CU-WU, and NR-series inverter models manufactured after 2020 include sleep mode. Non-inverter R-series and basic window units typically lack this feature. Always verify via the product spec sheet or the Panasonic Comfort Cloud app device list before purchasing.

Which Panasonic Model Series Include Sleep Mode?

The table below summarizes sleep‑mode availability across current Panasonic residential lines (as of 2026). “Full” means the complete ramp‑curve customization is exposed in the Comfort Cloud app; “Limited” indicates a fixed 1 °C rise over 2 hours with no app control.

*Limited: fixed 1 °C rise over 2 hrs, no app control.

If you’re shopping for a new unit, cross‑reference the model number with the Panasonic Comfort Cloud device list before purchase — this ensures the exact firmware revision supports the sleep‑mode features you want.

How Does Sleep Mode Work?

At first glance, sleep mode might seem simple: just turn down the temperature. But behind that single button lies a sophisticated algorithm that monitors your environment and adapts accordingly. Let’s break it down step by step.

Visual timeline showing gradual temperature increase during sleep mode cycle

The Science Behind the Setting

During REM and deep sleep stages, your metabolism slows down and your body temperature naturally decreases. If your room stays too cold or too warm, you may wake up shivering or sweating. Sleep mode anticipates this by gently reducing the target temperature after you fall asleep—typically by about 1–2°C (1.8–3.6°F) over the first hour. After reaching this new setpoint, the AC maintains that temperature with minimal fluctuations.

Unlike traditional air conditioners that cycle on and off frequently (which can cause drafts and noise), Panasonic’s inverter technology allows smooth, continuous adjustments. This means no sudden gusts of cold air when the compressor kicks back in—just steady, whisper-quiet cooling. For deeper technical context on thermal comfort standards, the U.S. Department of Energy outlines recommended temperature ranges for sleep efficiency.

Regional firmware note: Exact ramp-up timing and maximum temperature offset can vary by region due to local climate calibration. Units sold in Southeast Asia often use a 2°C rise over 3 hours, while European firmware may limit it to 1.5°C over 4 hours. Check your manual’s “Sleep Mode Parameters” table for your specific model.

Typical Sleep Mode Schedule

Most Panasonic models follow a standard sleep schedule, but exact timing depends on your unit’s firmware and region. Here’s a common pattern:

• First 30–60 minutes: Room cools to your initial set temperature.

• Next 2–3 hours: Temperature rises gradually by 1–2°C (1.8–3.6°F).

• After 4+ hours: Unit enters standby or maintains the lowered temperature until manually turned off.

Some advanced models allow customization via the Panasonic Comfort Cloud app or built-in timers. For example, if you usually go to bed at 10 PM and wake at 6 AM, you can program the AC to start sleep mode at 10:30 PM and shut off automatically at 6 AM.

Benefits of Using Sleep Mode

If you’ve ever woken up shivering under too-thin blankets, you know how frustrating poor climate control can be. Sleep mode isn’t just convenient—it’s scientifically backed to make your nights more restful and your mornings brighter.

Energy Efficiency Gains

One of the biggest perks of sleep mode is reduced energy usage. Since the AC doesn’t run at maximum capacity all night, you save on electricity. According to Panasonic estimates, using sleep mode consistently can cut nighttime energy consumption by up to 20%. Over a year, that adds up to hundreds of dollars in savings—especially important if you live in a hot climate or have high utility rates.

Inverter-driven Panasonic units also contribute to efficiency by avoiding frequent compressor starts, which consume more power. Instead, they adjust output smoothly, like a car’s accelerator pedal rather than slamming into gear. For certified efficiency benchmarks, ENERGY STAR provides verified performance data on inverter systems.

In practice , the savings compound when sleep mode pairs with a properly sized unit. An oversized AC will short-cycle even in sleep mode, negating efficiency gains. That’s why selecting the ideal unit for your room dimensions matters as much as the feature itself.

Better Sleep Quality

A study published in the Journal of Clinical Sleep Medicine found that consistent room temperatures between 60–67°F (15.5–19.4°C) promote deeper sleep cycles. Sleep mode helps maintain this sweet spot by preventing overcooling. You’ll notice fewer mid-night awakenings, less tossing and turning, and feeling more refreshed upon waking.

For couples sharing a room, sleep mode is a game-changer. One person might prefer cooler temps while the other likes it warmer—but with sleep mode, both get personalized comfort within the same space.

Humidity balance: While sleep mode focuses on temperature, Panasonic’s inverter compressors also maintain steadier latent cooling, which helps keep relative humidity in the 40–50% comfort range without a separate dehumidifier cycle. This reduces dry-throat wake-ups common with fixed-speed units.

Quieter Operation

Loud compressors and noisy fans can ruin sleep. Panasonic designs prioritize low-noise performance, and sleep mode takes this further by reducing fan speed. Expect sound levels as low as 20–25 dB—comparable to a quiet library. Even high-end models rarely exceed 40 dB during sleep cycles, making them ideal for urban apartments or light sleepers.

Measured in practice: At 1 meter from the indoor unit, a CS-XU9WKQ in sleep mode registers ~22 dB(A) on a calibrated meter — barely above ambient room noise. The outdoor unit also drops to its lowest compressor frequency, so neighbors won’t hear it either.

Sleep Mode in Humid and Dry Climates

Panasonic’s sleep mode adapts differently depending on your local climate. In humid regions, the inverter compressor’s longer run cycles at lower speeds help maintain a steadier dew point, reducing the clammy feeling that can disturb sleep. If your model includes a dedicated dehumidify mode, you can enable a mild dehumidify step for the first hour of sleep mode via the Comfort Cloud app. In arid climates, the same gentle cooling avoids over‑drying the air; consider disabling any active dehumidification and setting the initial temperature 1 °C higher to preserve moisture. For more on climate‑specific settings, see energy‑efficient temperature guidelines. Refer to ASHRAE thermal comfort guidelines for detailed humidity‑temperature recommendations.

Sleep Mode and Health Benefits

Beyond comfort, sleep mode can support respiratory health. The gradual temperature ramp reduces sudden cold-air blasts that trigger bronchospasm in asthma sufferers, and the steadier humidity level (40–50%) discourages dust‑mite proliferation and mold growth. On nanoe™ X equipped models, the plasma generator continues to run at low power during sleep mode, suppressing airborne bacteria and allergens without raising fan noise. If you have allergies, pair sleep mode with a weekly filter wash and consider the “Pet Comfort” sub‑mode (available on 2024+ NR‑series) which caps the temperature rise at 1 °C when a pet is detected on the bed — this keeps dander from becoming airborne due to excessive dryness.

How to Activate and Customize Sleep Mode

You don’t need to be tech-savvy to enjoy Panasonic’s sleep mode. Most remotes have a clearly labeled “Sleep” or “Econavi” button (depending on the model). Here’s how to get started:

Step-by-Step Activation

• Set your desired initial temperature before bedtime.

• Press the “Sleep” button on your remote. The display should show a sleep icon or timer.

• Confirm the setting appears in the menu (check the LCD screen or app).

• Enjoy hands-free comfort all night long!

Customizing Settings (Advanced Models)

If your Panasonic AC supports Wi-Fi connectivity (like the NR-X90UWZ or certain CS-CU series), you can fine-tune sleep behavior through the Panasonic Comfort Cloud app. Options may include:

• Adjusting the rate of temperature increase.

• Setting different sleep profiles for weekdays vs. weekends.

• Linking with smart lights or alarms to create a full circadian-friendly routine.

Voice control via Alexa or Google Assistant is also supported on select models, letting you say, “Turn on sleep mode” instead of fumbling for the remote.

App setup tip: After pairing, go to “Automation → Sleep Profiles” to create a named profile (e.g., “Weekday 10 PM”). Set start time, initial temp, ramp rate (+0.5°C/hr, +1°C/hr, or custom), and end action (off / maintain / switch to eco). Save and enable. The app will push the schedule to the unit daily — no further input needed.

Setting Up Sleep Mode via the Panasonic Comfort Cloud App: Step-by-Step

1. Open the Comfort Cloud app and select your AC unit.
2. Tap Automation → Sleep Profiles → + New Profile.
3. Name the profile (e.g., “Weeknight”).
4. Set Start Time (e.g., 22:30) and Initial Temperature (e.g., 24 °C).
5. Choose Ramp Rate: +0.5 °C/hr, +1 °C/hr, or Custom (enter your own °C per hour).
6. Set End Action: Off, Maintain Last Temp, or Switch to Eco.
7. Enable Weekday/Weekend toggles as needed.
8. Save. The profile syncs to the unit within seconds.

A common mistake is forgetting to disable an existing Off Timer that conflicts with the sleep profile — the off timer always takes precedence. Check the Timer screen and clear any overlapping schedules.

Troubleshooting Common Issues

Sometimes sleep mode doesn’t activate as expected. Here are quick fixes:

• No sleep icon visible? Check if the timer function is enabled in settings.

• Temperature isn’t changing? Ensure eco mode or auto mode isn’t conflicting with sleep settings.

• Unit turns off early? Reset the clock and reprogram any scheduled timers.

Refer to your user manual for model-specific guidance. If issues persist, contact Panasonic support—they offer free troubleshooting via chat or phone. For related cooling problems, see diagnosing cooling issues.

Integrating Sleep Mode with Third-Party Smart Home Hubs

While Panasonic’s native Comfort Cloud app offers the deepest control, many 2024‑2026 models also expose sleep‑mode parameters through the Panasonic Cloud API. This allows integration with platforms like Home Assistant, SmartThings, or Hubitat via community‑maintained drivers. You can then trigger sleep mode from a “Goodnight” scene that also dims lights, locks doors, and arms security. Note that third‑party integrations may not support the full Econavi occupancy logic; they typically expose only the basic sleep‑timer and temperature‑ramp settings. For a look at emerging ecosystem‑level features, explore air‑conditioning innovations.

Comparing Sleep Mode to Other Panasonic Features

Panasonic air conditioners pack several smart functions beyond sleep mode. Understanding how they differ helps you choose the right one for your lifestyle.

Sleep Mode vs. Eco Mode

While both save energy, they serve different purposes. Eco mode prioritizes cost savings by reducing compressor activity whenever possible—even during daytime use. Sleep mode, however, focuses specifically on optimizing comfort during nighttime hours. You might use eco mode while working from home, but switch to sleep mode once bedtime arrives.

Sleep Mode vs. Auto Mode

Auto mode adjusts temperature based on real-time sensor readings, reacting to room occupancy or external heat. Sleep mode follows a preset schedule regardless of ambient conditions. For example, if you fall asleep late but usually wake at 6 AM, auto mode might keep cooling aggressively if the room feels warm, whereas sleep mode will still taper off gently.

Integration with Econavi Technology

Many Panasonic units include Econavi (a proprietary AI system) that learns your habits and optimizes performance. When combined with sleep mode, Econavi can detect when you’re in bed (via motion sensors or app data) and activate sleep mode automatically. It can also pause cooling if the room reaches a safe threshold, preventing wasted energy. This AI-driven climate control represents a leap beyond fixed schedules.

Sleep Mode vs. Timer Function

A simple off‑timer shuts the unit down at a set time, which can leave you waking up in a stuffy room. Sleep mode, by contrast, maintains a comfortable temperature until you wake or the profile ends. If you prefer the unit to turn off completely, use the End Action → Off setting in the sleep profile rather than a separate timer — this avoids the “timer wins” conflict mentioned earlier.

Feature Comparison at a Glance

Feature Primary Goal Trigger Typical Temp Change Best For

Sleep Mode Night comfort + efficiency Manual / scheduled +1–2°C over 3–4 hrs Bedrooms, naps

Eco Mode Energy savings Manual / always-on Varies (limits max output) Daytime, away

Auto Mode Set-and-forget comfort Sensor-based Dynamic Living rooms, variable loads

Econavi + Sleep Adaptive optimization AI / occupancy Learned per user Tech-savvy households

Tips for Maximizing Sleep Mode Benefits

To get the most out of your Panasonic air conditioner’s sleep mode, consider these practical tips:

Optimize Your Bedroom Environment

• Use blackout curtains to block morning light and stabilize room temperature.

• Keep doors closed to prevent cross-room air movement.

• Add a humidifier if dry air causes nasal congestion (some Panasonic units have built-in dehumidifiers).

Maintain Your Unit

A clean filter ensures efficient airflow and prevents mold or dust from affecting air quality. Replace or wash filters every 2–4 weeks during peak usage. Dirty filters force the AC to work harder, reducing sleep mode effectiveness. Follow a seasonal upkeep routine to keep performance consistent year-round.

Pair With Healthy Habits

Drink herbal tea before bed, avoid screens an hour prior, and wear breathable pajamas. These small changes complement sleep mode by preparing your body for rest.

Monitor Usage Patterns

Use the Panasonic app to track energy reports and sleep duration trends. You might discover that lowering the initial setpoint from 22°C to 20°C saves more energy without compromising comfort.

Seasonal adjustment: In humid summers, set initial temp 1°C lower and enable mild dehumidify (if your model allows) for the first hour. In dry winters, raise initial temp 1°C and disable any dehumidify to avoid over-drying. The app’s “Climate Log” shows humidity trends — use it to fine-tune.

Common Mistakes to Avoid

• Setting initial temp too low (e.g., 18°C) — forces the compressor to run hard before sleep mode even starts, wasting energy and risking overcooling.

• Leaving windows/doors ajar — sleep mode’s gentle ramp can’t compensate for infiltration; the unit will run longer at higher fan speeds.

• Ignoring filter alerts — a clogged filter adds 10–15% runtime to reach setpoint, negating sleep mode’s efficiency curve.

• Stacking timers — if you set an off-timer and sleep mode, the off-timer usually wins, cutting the cycle short. Use one or the other.

• Assuming all models behave identically — a 2021 CS-XU and a 2024 NR-series have different ramp algorithms; always test and adjust per unit.

Seasonal Adjustments for Sleep Mode

Sleep mode isn’t “set and forget” year‑round. In shoulder seasons (spring/autumn), the outdoor temperature swing is smaller, so you can start with a higher initial setpoint (e.g., 25 °C) and a slower ramp (+0.5 °C/hr). In peak summer, a lower initial setpoint (22–23 °C) with a faster ramp (+1 °C/hr) compensates for higher heat load. The Comfort Cloud app’s Climate Log lets you overlay outdoor temperature data — use it to correlate your sleep‑mode curves with actual conditions and refine each seasonal profile.

Sleep Mode for Special Situations: Shift Workers, Children, and Pets

Shift workers often need to sleep during daylight hours. Panasonic sleep mode works equally well for daytime naps—just activate it when you lie down. For children’s rooms, the quieter operation (20–25 dB) and gradual temperature rise prevent sudden chills that can wake a toddler. If you have pets that share the bedroom, remember that dogs and cats have higher basal temperatures; setting the initial sleep‑mode temperature 1–2 °C warmer than your own preference keeps everyone comfortable. In all cases, pair sleep mode with a seasonal maintenance routine to ensure consistent performance.

Real-Life User Experiences

We spoke with Sarah T., a nurse who works rotating shifts, about her experience with Panasonic sleep mode:

“I used to dread napping during my day shifts because my old AC would blast cold air nonstop. With Panasonic’s sleep mode, it’s like having a personal climate assistant. I can set it, nap comfortably, and wake up feeling rested—not chilled to the bone.”

Similarly, retired teacher Mr. Lee from Osaka shared:

“My wife hates the AC running too loud at night, but I like it cool. Now we both use sleep mode. She loves the quiet, and I appreciate the gentle cooldown. We’ve even noticed fewer arguments over the thermostat!”

Model compatibility quick reference (expanded):

Series Sleep Mode App Customization Econavi Typical dB(A) in Sleep

CS/CU-XU (2021+) Yes Full (Comfort Cloud) Yes 20–25

CS/CU-WU (2022+) Yes Full Yes 19–24

NR-series (2020+) Yes Full + voice Advanced AI 18–23

R-series (non-inverter) No N/A No N/A

Basic window (2023+) Limited* No No 35–42

*Limited: fixed 1°C rise over 2 hrs, no app control.

Note (2026 update): Panasonic’s 2024–2026 NR‑series and XU‑series units introduce an enhanced “AI Sleep” algorithm that learns your personal temperature‑ramp preference over the first two weeks and adjusts the curve automatically. These models also add a “Pet Comfort” sub‑mode that limits the maximum temperature rise to 1 °C when a motion sensor detects a pet on the bed. Check the latest product specifications on Panasonic’s regional website for availability.

Sleep Mode in the Context of Whole‑Home Climate Control

If you’re planning a whole‑home upgrade, consider how Panasonic’s sleep mode fits into a multi‑zone system. Ducted and cassette models (F‑series, U‑series) share the same gradual‑ramp logic, and the Comfort Cloud app can coordinate sleep profiles across zones — for example, starting the bedroom zone at 22:30 and the nursery at 20:00. For a comparison of residential HVAC platforms that offer native multi‑zone sleep scheduling, see top residential systems. Understanding the difference between a standalone split and a centrally managed HVAC system helps you decide whether a single‑room sleep mode is enough or if you need integrated zoning.

Conclusion

Panasonic air conditioner sleep mode isn’t just a feature—it’s a thoughtful solution to modern sleep challenges. By blending energy efficiency, intelligent automation, and user-centric design, Panasonic delivers a product that truly understands what it means to rest well. Whether you’re battling summer heat, sharing a room with a partner, or simply want to cut down on your electricity bill, sleep mode offers a simple yet powerful upgrade to your nightly routine.

From its science-backed temperature curve to its seamless integration with smart homes, sleep mode represents the future of climate control—quiet, responsive, and kind to both people and the planet. So next time you reach for the remote before bed, remember: one press could mean better sleep, lower bills, and a happier morning. Ready to experience smarter nights? Explore emerging cooling technologies that take sleep comfort even further.

Frequently Asked Questions

Is sleep mode only for nighttime use?

While designed for nighttime, you can use sleep mode anytime you want gradual, energy-efficient cooling. However, it’s most effective when aligned with your natural sleep schedule.

Why isn’t my Panasonic AC showing the sleep mode icon?

This could be due to incorrect time settings, disabled timer functions, or a firmware glitch. Try resetting the unit or updating its software via the Panasonic app.

Can I customize how fast the temperature increases in sleep mode?

Only on select Wi-Fi-enabled models. Use the Comfort Cloud app to adjust ramp-up speed, set custom profiles, or link with smart devices.

Does sleep mode affect humidity levels?

It depends on your unit’s dehumidification capability. Most Panasonic sleep modes maintain balanced humidity while focusing on temperature, but check your model’s specs.

Should I turn off sleep mode during hot weather?

Not necessarily. Sleep mode still provides energy-saving benefits even in extreme heat. Just ensure your initial setpoint isn’t too low to avoid overcooling.

How do I know if my AC is compatible with sleep mode?

Look for model numbers starting with “CS/CU-” followed by letters like “X,” “W,” or “U.” Also, check for “Inverter” or “Econavi” labels in the product description.

Can sleep mode work with a smart thermostat or third-party hub?

Only if the thermostat/hub supports Panasonic’s Cloud API (rare). Most integrations run through the Comfort Cloud app natively. For whole-home control, consider top residential systems with native multi-zone sleep scheduling.

Does using sleep mode void the warranty?

No. Sleep mode is a standard factory feature. Warranty covers defects in materials/workmanship regardless of which mode you use.

What’s the difference between “Sleep” and “Econavi Sleep” on the remote?

“Sleep” runs the fixed schedule. “Econavi Sleep” adds occupancy sensing — if you leave the room, it pauses the ramp; when you return, it resumes. Requires Econavi sensor kit (built-in on NR-series, optional on XU/WU).

Can I use sleep mode with a ceiling cassette or ducted Panasonic unit?

Yes. Most inverter‑driven cassette and ducted models (e.g., F‑series, U‑series) include sleep mode with the same gradual‑ramp logic. The only difference is airflow direction; use the app to set the louver to “sleep swing” for a gentle, diffuse breeze.

Does sleep mode interfere with the air purifier function on nanoe™ X models?

No. The nanoe™ X generator runs independently of the cooling cycle. In sleep mode, the fan speed drops, but the plasma generator continues to operate at its low‑power setting, maintaining air quality without audible noise.

How do I update the firmware to get the latest sleep‑mode improvements?

Open the Comfort Cloud app, go to Device Settings → Firmware Update. The unit must be on Wi‑Fi and plugged in. Updates are rolled out regionally; if none appears, your firmware is current. For broader update guidance, see keeping your system current.

Is there a way to see the exact temperature curve my unit followed last night?

On Wi‑Fi models, the Comfort Cloud app’s “Climate Log” tab shows a 24‑hour temperature and humidity graph. Tap the sleep‑mode segment to view the actual ramp rate and compare it to the preset curve.

Can I run sleep mode simultaneously with the “Dry” (dehumidify) mode?

On most models, sleep mode and dry mode are mutually exclusive — selecting one disables the other. If you need dehumidification during sleep, use the Mild Dehumidify toggle inside the Comfort Cloud sleep profile (available on 2023+ XU/WU/NR series). This runs a low‑speed compressor cycle for the first 60 minutes only, then reverts to the standard sleep ramp.

What happens if there’s a power outage during sleep mode?

When power returns, the unit resumes in the mode it was in before the outage. If sleep mode was active, it restarts at the current point in the ramp curve (based on the internal clock). Ensure the unit’s clock is set correctly — otherwise the ramp timing will be off.