A message that says ‘return’ might, at one point, appear on a thermostat and confuse quite a few homeowners. The good news is that there is nothing to worry about.
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Your thermostat will say ‘return’ whenever it is running its return schedule. The schedule of programmable devices is usually divided into four segments – ‘return’ is the part of the schedule that kicks in when you are about to come back home from work or school.
Why Does Thermostat Say Return?
Programmable thermostats operate according to a set schedule. This schedule is usually divided into four segments – Wake, Leave, Return, and Sleep.
The Return part of the schedule is responsible for the time of the day when you come back home. During the Leave segment, the thermostat lowers the energy consumption, and when the Return segment takes center stage, the thermostat adjusts the settings so that you come back home to a comfortable temperature.
The ‘return’ message on your device simply means that the Return schedule is running at the moment.
Read: Temperature Thermostat Problems
What Does AC Return Mean?
‘Return’ means absolutely different things in thermostats and HVAC units. While on a thermostat, the ‘return’ message simply indicates a certain part of the programmed schedule, the ‘return’ in an air conditioner usually refers to the return air vent.
Return air vents suck in the air from the rooms in your house and send it to the air conditioning or heating unit through the ducts. So, these vents ‘return’ the air to the HVAC system.
Why Is Return Flashing on My Honeywell Thermostat ?

‘Return’ indicates that the thermostat is currently operating according to the return schedule.
By default, the return time period on a
You would have to set the correct time and schedule the weekdays and the weekends for all the time periods (Wake, Leave, Return, and Sleep).
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Fact: you can save up to 10% per year on your heating and cooling costs if you program your thermostat to adjust the temperature by 7-10 F for 8 hours every day.
Read: Benefits Of A Programmable Thermostat
What Does FR Return Mean on a Thermostat?
The ‘FR Return’ message simply means that the thermostat’s return program is running and that it is Friday.
What Happens If There Is Not Enough Return Air?
If there is not enough return air, the HVAC system will not be able to heat or cool properly. A system that does not have enough air, will struggle to reach the set temperature.
Issues with the airflow will also affect the lifespan of the system’s components. The elements will get worn down faster and the unit might even break down if there is not enough air flowing through the system.
Finally, return air vents help maintain the proper air pressure in your house. The amount of air that gets ‘pushed’ into the house should equal the volume of air that gets sucked back into the system, otherwise, there will be a pressure imbalance.
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Are Return Vents Necessary?

Return air vents are absolutely essential if you have an HVAC system with ducts. The system simply wouldn’t have any air to cool or heat without the return vents.
What Is the Purpose of Cold Air Return Vents?
Cold air return vents (return air grills) are typically located closer to the floor where they get to capture the cold air that ‘sinks’ to the floor.
The air then travels through the ducts back to the furnace where it gets filtered, heated, and then sent back to the house.
Read: HVAC Thermostat Problems
How Do I Know If I Have Enough Return Air?
If you have noticed one of these symptoms, it means that there is not enough return air in the house:
- Hot and cold spots – the rooms that are closest to the HVAC unit are hotter/colder and have a bigger airflow.
- A variation in air pressure in the rooms – you can check that by using a barometer or by simply paying attention to how you feel (for example, your ears might hurt in some rooms).
- The air conditioner is blowing warm air and the furnace is blowing cool air – if there is not enough air coming from the return vents, there will be issues with the supply air as well.
How Do I Know If My Return Air Is Working?

The easiest way to test your return vents is to get tissue paper and hold it around 6 inches away from the vent. If the return air is working, you should notice the tissue being gently pulled towards the vent.
After that, you can place the paper against the vent – properly working return air should be able to hold the tissue in place.
Can There Be Too Much Return Air?
It is practically impossible to supply too much return air. In extreme cases, a closed room can temporarily stay under negative pressure, if there are a few return vents, but that will get fixed as soon as you open the door.
Is It OK to Block a Return Vent?
You shouldn’t block the return vents even in the rooms that you don’t use. By closing the vents or blocking them with furniture, you will be causing a lack of airflow, which, in its turn, might lead to:
- Inefficient heating and cooling
- High energy bills
- A frozen coil
- A damaged outdoor compressor
- A cracked heat exchanger (which can potentially lead to a carbon monoxide leak)
Does Each Room Need a Return Vent?
Some homes have one large return air vent somewhere in the center of the house. That might not be a problem if you tend to always leave all the doors in the house open.
In all the other cases, having a return vent in every room would be a lot more beneficial as this will help make sure that each space has its own supply of fresh air and a return.
Do bear in mind that larger rooms might require a couple of return vents.
An HVAC engineer would take the CFM output of the furnace into consideration when counting the number of return vents necessary. However, you can use the rule of the thumb, and simply install a return air vent in every room that is larger than 100 square feet.
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Why Does the Thermostat Say Leave?
Leave is the time period on your thermostat that you can use as an energy-saving mode while you’re at work.
How Do I Turn Off the Leave on My Honeywell Thermostat ?
You can choose to remove the schedule completely from your
- Press and hold the + and ‘menu’ buttons for 5 seconds.
- Once you have entered the advanced menu, select ‘ISU menu’.
- Set the ISU 120 number to ‘0’ to disable the schedule.
- Once you cycle through all the System Setup numbers, ‘done’ will be displayed. Press ‘select’ to save the changes.
How Do I Return My Honeywell Thermostat ?
To process your return, contact Honeywell within 30 days after you have received your thermostat.
Bear in mind that all warranties start from the date of purchase (you should save the applicable receipt).
Why Won’t My Honeywell Thermostat Stay On?
Your
- The batteries are nearly dead
- There is a refrigerant leak
- The air filters are clogged
- The HVAC system is too big for your house
What Does Hold on Honeywell Thermostat Mean?
The ‘hold’ button allows you to lock in the temperature that the thermostat is currently at. You can then cancel the hold manually (a temporary hold will expire on its own).
Read: Why Does The Room Temperature Not Match The Thermostat Setting?
How Long Is Temporary Setting on Honeywell Thermostat ?
A temporary hold will stay until the next change in the schedule. However, such a hold cannot stay for longer than 11 hours.