Why Is My Carrier Thermostat Blinking COOL ON? 5 Quick things to check.

Is your Carrier thermostat blinking COOL ON at you? Egads! We’re used to thinking that any blinking message on a thermostat is a bad sign. However, that’s not necessarily the case with ‘Cool On’.

Your Carrier thermostat will have a blinking ‘Cool On’ message when the system goes into a delay mode – that is done to prevent the equipment from short-cycling. Under normal circumstances, the message will go away in 5 minutes, and the unit will start cooling your house.

What Does It Mean When Your Thermostat Says ‘Cool On’?

‘Cool On’ is your system’s special mode that is regulated by the thermostat. It is there to inform you that your AC has been turned on and is now cooling your house.

Why Is ‘Cool On’ Flashing on My Carrier Thermostat?

If ‘Cool On’ is flashing for only a few minutes, then you have nothing to worry about. It is a built-in safety measure that prevents short-cycling and protects the compressor from getting damaged.

Read: Carrier Furnace Error Codes – Troubleshooting Guide

In the majority of cases, ‘Cool On’ is a delay message. You would simply have to wait for a few minutes and the unit will get back to normal operation. 

In about 5 minutes, the message should stop flashing. However, if it doesn’t, this might be an indication that there is something wrong with the system.

Carrier Thermostat Blinking COOL ON, But No Cold Air

Here are a few things that you can try to do:

  1. Set the thermostat to the lowest possible temperature – the mode should be ‘cool’ and the fan should be set to ‘auto’. Leave the unit for a while and check whether the system is going to start cooling or not.
  2. Check other thermostat settings – something might have made your thermostat switch back to setup mode. Also, check the time on the device, as wrong settings can make the ‘cool on’ indicator start blinking.
  3. Replace the batteries or check the wiring (if your device is not battery-operated).
  4. If none of these steps make a difference, then you would have to check the actual cooling unit. Make sure that the system is getting power (you can also try turning the equipment on and off at the circuit breaker).
  5. Check the fuses (if equipped) at the AC unit disconnect box.
  6. Check your AC filter and replace it, if there is such a need. 
  7. Make sure that the AC coils are clean.
  8. At times, resetting the thermostat might resolve the issue. 
Carrier Thermostat

Read: Why Furnace Not Responding To Thermostat?

What If My AC Isn’t Blowing Air?

If there is no air coming from the vents, then:

  • Check the thermostat settings
  • Replace the air filter (or temporarily remove it for a test)
  • Make sure that the system is receiving electricity

If there is warm air coming from the vents, then:

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  • Make sure that the fan is set to ‘auto’ (not ‘on’)
  • Replace the air filter (or temporarily remove it for a test)
  • Service the outside unit, as described above
Carrier thermostat blinking COOL ON

Should the Thermostat Be on ‘Auto’ or ‘On’ for Cool?

Setting your fan to ‘on’ will help distribute the cool air around your house more evenly as the fan will continue to operate even when the air conditioner stops.

However, that is pretty much the only benefit of leaving the fan on.

Switching the setting to ‘auto’ will make the fan work only when the cooling or heating is on. This is, of course, a more energy-efficient option.

Moreover, the ‘auto’ setting allows the moisture from the coils to drip and get drained outside during the warmer months. If the fan is running continuously, the moisture won’t get removed and will end up getting blown back into your house.

Finally, if you have ducts in the attic, they can get filled with warm air during the summer. If the fan is always running, the hot air will get transferred into your house.

Read: Temperature Thermostat Problems

Should I Have My Thermostat on Heat or Cool?

This one is pretty straight-forward. If your house is too warm, then use the ‘cool’ setting. If it has become a bit chilly, then turn the system to ‘heat’ to bring it back up to your comfort level.

‘Auto’ will keep the temperature of your house within a certain set range of temperature of your choosing – regardless of the conditions outside.

By the way, with most modern thermostats, your HVAC system can work even when all of these settings are off. You can choose to turn the fan to ‘on’ to circulate the air around the house more efficiently and to freshen up stale spaces, for example.

Read: Benefits Of A Programmable Thermostat

How Do You Turn Your Thermostat on Cool?

The ‘cool’ mode runs the air conditioner and lets you pick the maximum temperature. If the temperature rises above the setting, the thermostat will make the air conditioner kick on.

‘Cool’ mode also helps dehumidify the house. 

Depending on the thermostat model, you would either have to pick the ‘cool’ mode on the device’s faceplate or use a cycle button to choose between ‘heat’, ‘cool’, ‘auto’, and ‘off’

What Temperature Should I Set My AC to?

Thermostat digital display

78 degrees Fahrenheit is the perfect balance between comfort and energy savings, in most cases. Of course, you should experiment with the settings to find the perfect one for you.

By the way, if you want to save on your cooling costs, then you can allow the temp to rise when the building is unoccupied and during sleep. These ‘setups’ can result in up to 18% of energy savings.

Do You Turn the Thermostat Up or Down for Air?

If you want to make it warmer, then turn the thermostat up and vice versa.

In case, you simply want the unit to help you circulate the air around the house, you can switch the fan to ‘on’ without actually touching the thermostat temperature settings.

Read: HVAC Thermostat Problems

How Cool Should My House Be If It’s 90 Outside?

Air conditioners are designed to be able to cool your house to a temperature that is 20 degrees lower than the outdoor temperature. So, if it’s 90 F outside, you can easily get your house to 70 F.

However, keeping the indoor temperature at around 78 F or even 80 F would be a lot more energy-efficient. 

What Does It Mean When Your Furnace Light Is Blinking?

blinking furnace light

A blinking red light can mean that there is an issue with the pressure switch or inducer, furnace lockout, ignition failure, an open high limit switch, and so on.

Pay attention to the light sequence and consult the owner’s manual.

A flashing green light usually means that either the furnace is providing heat at the moment or that the furnace is on but there is no call for heat.

Why Is My Thermostat Blinking ‘Heat On’?

In the majority of thermostats, ‘heat on’ means practically the same thing as ‘cool on’, except with heat. The HVAC unit will be ready to provide heat as soon as a 5-minute delay comes to an end.

This safety measure saves the equipment from getting damaged during short cycling. 

What Does A Blinking Flame on My Thermostat Mean?

The flame icon on a thermostat can start flashing if the compressor gets locked. This might happen after an interruption of some sort, including power loss.

Usually, simply resetting the thermostat should solve the problem. 

Why Is My AC Not Coming On?

  1. A thermostat-related issue
  2. A low refrigerant level
  3. Clogged air filters
  4. A faulty capacitor
  5. A dirty condenser
  6. A tripped circuit breaker
  7. A blown fuse in the AC disconnect
  8. A damaged motor
  9. A clogged drain pan
  10. A faulty power cord

Why Is My Thermostat Not Turning the Heat On?

You might have to replace the thermostat’s battery. Also, make sure that the thermostat didn’t lose its settings – this could have happened during a power outage, for example.

thermostat wiring connections

Loose or damaged wires and no Wi-Fi connection (if equipped) might also be to blame.

What Does ‘Wake’ Mean on My Thermostat?

The thermostat sets a certain temperature during the ‘wake’ period – the time of the day when you are awake. By default, the ‘wake’ period is usually between 6 a.m. and 10 p.m.

Should I use My Ceiling Fan Together with My AC?

It is a common belief that ceiling fans and air conditioners should not be used together. It is argued that the warmer air will get pushed closer to the floor, making you feel warmer.

However, the air movement by the fan also creates a breeze against your skin, which has a cooling effect (i.e. the wind chill factor). In fact, using a ceiling fan together with an air conditioner allows you to raise the thermostat setting by around 4 F and still feel comfortable.

Read: Why Does The Room Temperature Not Match The Thermostat Setting?