On this page
- Delay on and delay off are two separate settings
- Timer ranges and steps by model
- The compressor adds a few minutes at the start
- Timer or sleep mode?
- Scheduling from an app instead of the buttons
- Where a delay timer is worth setting
- What a timer does not do
- Confirming the timer is set
- Which to choose
- Questions people ask
Delay on and delay off are two separate settings
A delay on timer holds the unit off for a set number of hours and then starts it. A delay off timer does the opposite: the unit runs now and stops when the countdown ends. Neither one changes the set temperature. They only decide when the compressor and fan start or stop.
The LG manual for the LW1022FVSM describes both. With the unit off, the delay on setting turns it on from 1 to 24 hours later, at the mode and fan speed it was using before. With the unit running, the delay off setting turns it off somewhere between 1 and 24 hours later. Each press of the Timer button adds one hour, and after the last press the display goes back to the temperature.
Whynter describes the same pair on the ARC-102CS. With the unit running, press the Timer button and the TIMER OFF light comes on, then set the hours; when the delay elapses the unit switches off. With the unit off, press the Timer button, the TIMER ON light comes on, and the unit switches on once the delay has passed. Setting the time to 0.0 cancels either one.
Midea's MAW06R1WWT-T uses one Timer button for both directions. The first press brings up the TIMER ON setting when the unit is off, and the same button moves on to the auto stop program. That manual sets the time in 0.5 hour increments up to 10 hours.
Timer ranges and steps by model
The ceiling matters more than it sounds. A 24 hour range covers a full day, so a start time can be set the evening before. A 10 hour ceiling covers one overnight block but not a full day.
These figures come from the manuals for the named models. Controls vary within a brand, so check the page for the exact model rather than assuming the next unit in the line behaves the same way.
| Model | Timer range | Step or control | Notes |
|---|---|---|---|
| LG LW1022FVSM | 1 to 24 hours | One hour per press of the Timer button | Delay on resumes the previous mode and fan settings |
| Midea MAW06R1WWT-T | 0.5 hour steps up to 10 hours | One Timer button for the on and off programs | Display returns to the temperature after setting |
| Whynter ARC-102CS | 0 to 24 hours | Hours, set with the timer buttons | Setting the time to 0.0 cancels the delay |
| Whynter ARC-1030WN | 0 to 24 hours | Panel and remote | Remote has separate Timer On and Timer Off buttons |
| Whynter ARC-1280MX | Up to 24 hours | Panel and remote | Timer on and off indicator lights on the display |
The compressor adds a few minutes at the start
A delay on timer does not deliver cold air at the exact minute it fires. Whynter's manuals describe an automatic 3 minute time delayed start when the unit is switched off and on quickly, which protects the compressor. Midea's manual explains the same idea for a switch from cool to fan and back to cool: the pause prevents the compressor from overheating and tripping.
So when the timer starts the unit, expect the room to begin cooling a few minutes after that point. Setting the start earlier than you need is more dependable than aiming at the exact minute.
Timer or sleep mode?
Both can switch a unit off overnight, but they do different jobs. A delay off timer stops the unit at a fixed time and leaves the set temperature alone. Sleep mode changes the temperature as the night goes on.
On the Midea MAW06R1WWT-T, sleep raises the set temperature by 2 °F after 30 minutes and by another 2 °F after another 30 minutes, holds that level for 7 hours, then returns to the original setting. Whynter's ARC-102CS raises the set temperature by 2 °F at the same 30 minute marks and holds it for 7 hours. LG's LW1022FVSM raises the setting by 2 °F after 30 minutes and another 2 °F after 30 more, and its sleep mode also turns the unit off after a set time.
If the goal is simply to stop the unit at a chosen hour, a delay off timer is the direct tool. If the goal is to stop it and let the room warm gradually, sleep mode does both in one setting.
Scheduling from an app instead of the buttons
ENERGY STAR counts scheduling among the connected features of certified room air conditioners: owners can arrange temperature setting changes around their own routine, switch the unit off from elsewhere, and see feedback on energy use. It also notes that many connected models are smart-grid ready.
That is a different kind of control from a countdown. A panel timer sets a number of hours from now. An app schedule sets target temperatures for times of day, which can involve several setpoint changes along the way. LG's LW1022FVSM connects through the LG ThinQ app, and Whynter's smart portables pair with an app as well. The Wi-Fi and app overview covers what those connections add.
Where a delay timer is worth setting
The clearest case is a bedroom. Set a delay off to run a while past bedtime and the unit stops while the room is still cool. Midea's troubleshooting notes point to stored heat in walls, ceiling, floor and furniture as a reason a room takes time to cool, which is also a reason to give a delay on timer a head start before you arrive. More on setup in cooling a bedroom.
The second case is arriving home. A delay on set ahead of your arrival gives the unit a head start, and on the LG it resumes the mode and fan speed you left it in, so nothing needs resetting.
A third case is a room used at fixed hours, such as a home office. A delay off at the end of the workday avoids leaving the unit running into the evening.
What a timer does not do
It does not change the set temperature, so a unit set to a given temperature will still aim for that temperature when the timer starts it. It does not make an undersized unit cool a room it cannot handle either; the capacity limits are the same whether the unit starts by button or by timer. The signs of an undersized unit are worth checking before you blame the schedule.
It also does not guarantee the same behavior after a power cut. Whynter's manuals state that the unit restarts at the previously set mode and settings when power returns, and LG's LW1022FVSM lists an Auto Restart function that brings the unit back with the same settings once power is restored. Neither manual describes a countdown resuming where it left off, so treat power outage behavior as a separate question from the timer.
And it does not replace the thermostat. While the timer is counting down, the unit still cycles on and off around the set temperature.
Confirming the timer is set
Most controls show a light rather than a countdown. Whynter's ARC-102CS has TIMER ON and TIMER OFF lights, the ARC-1030WN has a timer on/off indicator that illuminates when the timer is set, and Midea's control has a TIMER ON indicator light.
On LG and Midea controls the display returns to the temperature after the last press. That is normal and does not mean the timer was rejected; the indicator light is the confirmation. If a remote is involved, Whynter notes that curtains, doors or other obstructions between the remote and the unit block the signal, and that direct sunlight on the receiver can stop the unit responding. The remote troubleshooting page walks through those checks.
Which to choose
| If you | Look for |
|---|---|
| If you want the room already cool when you get home | A delay on timer set ahead of your arrival, on a control that resumes the previous mode and fan speed, as the LG LW1022FVSM does. |
| If you want the unit to stop after you fall asleep | A delay off timer for a fixed stop, or sleep mode if you also want the set temperature to climb during the night. |
| If half-hour precision matters to you | A control that sets the timer in 0.5 hour steps, such as the Midea MAW06R1WWT-T, rather than one that moves in whole hours. |
| If you want the set temperature to change on a schedule, not just switch on and off | A connected model with app scheduling, which ENERGY STAR lists among the connected features on certified units. |
| If the display goes back to the temperature right after the timer is set | Look for a timer indicator light. The display reverting is normal on LG and Midea controls and is not a failed setting. |
| If you want to cancel a delay that is already set | On the Whynter ARC-102CS, set the time back to 0.0, or switch the unit the way the timer would have; other controls differ. |
Questions people ask
Does a delay off timer stop the whole unit or just the compressor?
The manuals describe the whole unit switching off. Whynter's ARC-102CS says the air conditioner switches off when the delay time has elapsed, and LG's LW1022FVSM describes the delay off setting as automatically turning the air conditioner off.
Can a delay on and a delay off be set at the same time?
The Whynter ARC-102CS manual treats them as separate settings: with the unit running you set the off delay, and with the unit off you set the on delay. Midea's MAW06R1WWT-T uses one Timer button that steps between the TIMER ON and auto stop programs, so check the display as you go.
Will the unit remember the temperature and fan speed when the timer starts it?
On the LG LW1022FVSM, the delay on setting turns the unit on at its previous mode and fan settings. That is the behavior LG states for that model; other controls may differ.
Why does the display go back to the temperature after the timer is set?
LG states that after the last press of the Timer button the display returns to the temperature setting, and Midea's manual describes the display reverting to the previous temperature or room temperature. The timer indicator light, not the number on screen, tells you the delay is active.
How is a delay cancelled once it is set?
Whynter's ARC-102CS manual gives two ways: set the time back to 0.0, or switch the unit the way the timer would have (off for a delay off, on for a delay on). Other models use their own button sequence, so the indicator light is the thing to watch.
Do portable air conditioners have the same timers as window units?
Several do. Whynter lists a 0 to 24 hour timer on the ARC-102CS portable and a 0 to 24 hour timer setting on the ARC-1030WN, and the ARC-1280MX lists a timer of up to 24 hours. The control layout differs from a window unit, but the delay on and delay off idea is the same.
Is a timer the same as a thermostat schedule?
No. A timer switches the unit on or off at a set number of hours from now. ENERGY STAR describes connected scheduling as the ability to schedule changes to temperature settings, which can move the setpoint rather than only the power state.