Why Is Cold Air Blowing Out Of Vents When The Heat Is On?

It may happen with you that when you came back home on a chilly day, you want to warm up, but you see cold air blowing out of vents while the heat is on. No need to worry; it is a common problem and occurs frequently.

You have checked the vent, but you could not identify why cold air is blowing out when heat is also on. You are not an expert, but some simple reasons that cause that problem can locate by yourself.  To teach you why cold air blows out of vents when heat is on, we have researched and found some primary reasons. Read the below content and know about significant reasons.

What are common reasons for cold air blowing out of vents when heat is on?

Here are some significant problems that can cause such issues; I hope it will help you identify the problem and resolve it immediately.

Thermostat issue

Check thermostat some of the problems such as a heater is not blowing air even the fan is working. When the heater inside the vents off, then air blows out of the vents will be cold because it will be the same as your room temperature that will feel cold in the winter season.

Here is a simple solution to that problem; you need to reset the thermostat and get the right temperature level of blowing air. First, ensure that problem is not with the fan and maybe your thermostat is off; if it is off, then switching it on, you will get hot air after a couple of minutes.

But if the switch is ON, but still cold air is blowing, then there is a problem with the thermostat setting. Make some adjustment with the thermostat and set it on auto mode, it will adjust on the right level, and the setting will restore in a minute, and vents start blowing warm air.

Air Filter is problematic.

If there is no problem with the thermostat, there could be a problem with the air filter. Clogged air filters can cause cold air to blow out of vents when heat is on. Check the filter and clean it if there is dirt or debris and recheck it.

But if you see that it is not possible to clean it, you can replace it with a new one. A clogged air vent stops the air from passing, and vents become overheat due to overheating; vents trip and switch off and could not provide the required performance. But before replacing the filter, you should wear all the safety gadgets.

Problem with Condensate line

If you have a vent with water pooling around it, then condensate blockage can be the reason for cold air blowing out of vents. Due to blockage of condensate line vent will shut down. Heavy-duty vents also create water while working; water flows inside the condensate line can cause blockage of the condensate line.

When water overfills in the vent furnace switch off due to tripping, it will protect the vents from turning ON and protect the system from water damage. Commonly it happens due to mold, dirt, dust, and cold snap or ice.

A broken condensate pump can also be the reason for the condensate line’s blockage; if there is such a problem, you will need to call an expert to resolve it. It will not be possible for you to remove that issue.

Maybe your vent system just turned on.

Another simple reason can be that if you have set the system on auto function. The system turned off due to auto setting; when you come back home, it just turned. No need to do anything; waits for two or three minutes to check. Suppose hot air starts blowing, then no need to do anything.

The flame sensor is problematic.

A flame sensor plays a vital role in detecting whether or not the vent burners are lit, but a dirty flame sensor cannot detect. Over time the sensor becomes dirty and could not perform its functions. So it is good to check it and replace it if needed to get rid of the problem.

Problem with Heat limit switch

The heat limit switch is responsible for temperature maintenance. You can set any of the required limits for the temperature. When your room or air temperature reaches to set limit, the system will stop working. After some time, it will automatically switch on to reach the required level of temperature.

But if there is a problem with the heat limit switch, then it can cause a problem like cold air blowing out of vents when heat is on. Click here. You can check its adjustment, and if there is a need, you can go for the replacement of the switch with a new one for proper functioning.

Also Read: Top 10 Best Heater Fan in 2021

What are helpful tips for troubleshooting vents problems?

Many reasons can cause cold air to blow, but the following tips will help you troubleshoot the problem quickly.

  • Check thermostat that it is functioning correctly.
  • You should check that there is no damage with vents on any part
  • Make a check of thermostat batteries, sometimes due to batteries problem occurs, and thermostat stops working
  • Also, check the thermostat heat adjustment features; it should be correct
  • Check the circuit breaker periodically due to overheating or any other issue; the power tripped, and the vents stop working.
  • Check the flame sensor that works appropriately and also should be in good condition.
  • You should check the power or fuel such as electricity and fuel supply
  • It is also good to check the vent filter; maybe the problem is due to a clogged air filter.
  • You should check the holes and leaks in the air ducts can cause cold blowing air from vents.
  • If there are no such problems and you cannot troubleshoot the issue, contact a trusted expert for vent repairing.

Final Thoughts:

There are many reasons for problems with vents, such as cold air blowing out of vents when heat is on. We have also shared some of the most occurring causes in the above content. We hope it will help you to locate the troubleshooting to resolve the problem quickly.

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