furnace blowing cold air

What Can I Do if My Electric Furnace is Blowing Cold Air?

If your electric furnace has started to blow cold air, you’ve got a problem on your hands. However, there is no need to panic just yet, as many of the culprits that could cause this issue can be easily repaired by yourself at home. So before you go ahead and call a technician, it’s worth running through the list below to see if you can take care of it without too much stress.

Some of the things in the list are as simple as making sure there are batteries in your thermostat remote. Others are more complex and require a little bit of know-how and experience to fix the issue.

However, if for any moment you suspect something is seriously wrong with your system, or if you think there is a health and safety hazard such as a gas leak, please give us a call immediately, and we will be right on hand to get your system repaired

Dirty Filter

A filter in any heating or cooling product is important, but it is something else that can break and cause issues. If your filter gets dirty, it can block the airflow in the heat exchanger. This can mean that the whole furnace overheats. As a result, it may break and cooler temperatures might come out of the furnace.

If this is the case, you may just need a filter to be replaced. So how do you go about changing a dirty filter? The good news is that filters are pretty cheap and easy to change, so it won’t require too much elbow grease to swap it out. Here are some easy steps for you to follow:

  • Switch the furnace off and locate the filters (usually near the blower motor behind an access panel)
  • Remove the filter and check the dimensions (these are typically printed on the frame)
  • Buy a matching filter if you don’t have one already.
  • Put the new filter into the furnace – make sure it’s the right way up. There should be arrows that indicate the proper airflow direction.

As a rule of thumb, you should check your furnace filter at least once per month so you can change it before it gets too dirty. This will help you save on utility bills, and it will extend the life of your electric furnace.

If you want to know more about how to replace the filter yourself, click here for further instructions.

Thermostat Settings

ThermostatIf you have a heater blowing cold air then you might feel incredibly stupid if it is because of the thermostat settings. Some furnaces can be hard to control and it is possible that you have simply got the settings wrong.

Unfortunately, you might have to go back to the manual and check on the controls. Have you inadvertently set a timer that has turned the thermostat down to a certain temperature? Some thermostats even have automatic settings that sometimes don’t do the best job of sensing the temperature you need.

Before you go and call a technician to diagnose your electric heater issue, it’s worth making sure that your thermostat setting isn’t the culprit. Here are a few of the main issues with their solutions:

  • Fan settings

    – Oftentimes, it’s the fan settings that cause your furnace to blow cold air. If you have your fan set to “always-on”, it will inevitably blow cold air out when your furnace is having some downtime. The solution here is to set your fan to “auto” so it can correlate with the furnace.

  • Your thermostat is out of batteries

    – This might sound silly, but it never hurts to check the batteries to make sure they aren’t dead.

  • Your thermostat isn’t appropriately calibrated

    – For one reason or another, your thermostat might not be fully calibrated with your furnace. This could be for a number of reasons, but mainly because of issues during the installation. The solution for this is to completely reset your thermostat and try to calibrate it correctly with your furnace. Are you sure you are using the correct model and specification?

Fuses and Circuit Breakers

It may be that your furnace simply needs a new fuse. Fuses can go when there is an electric surge, or just over the time they can stop working. It is worth replacing the fuse within your electric furnace to see if this is the case.

No matter what source of fuel your heater uses to generate heat, the likelihood is that many of the components will still rely on electricity to communicate with each other when they are working. If for some reason, the circuit has been broken or a fuse has blown, your heater won’t work until you repair it. Here are steps on how to get it back up and running:

Step 1 – Locate the electrical panel for your heater

Hopefully, by now, you already know where your electric panel is. If you don’t, it’s normally located in the basement, garage, or in a closet somewhere hidden away. These panels are usually a bit of an eyesore, so they won’t be hidden in plain sight. In general, they look like a large gray metal box, but they may have been painted to blend in with your home.

Step 2 – Reset the circuit breaker

In general, most homes in the USA operate using a circuit system rather than fuses. If that’s the case for you, then when you find your circuit breaker box, you should be greeted with a bunch of circuit breaker switches in neatly organized rows. The top switch normally controls your whole house’s power, so don’t mess with that one.

In most cases, each circuit breaker is attributed to a certain room or area of your house. Sometimes they represent one system (such as your HVAC/furnace). So here’s what you need to do:

If your circuit breaker is labeled and you can see the furnace is in the off position. Switch it on

If it’s not labeled, go through each switch using trial and error until you figure out which one is responsible for the furnace. If your furnace has tripped, you should see the circuit breaker switch in the “off” position or even in the middle between on and off. Turn the circuit breaker back on, and your furnace should be good to go.

Replace a blown fuse

If a fuse has blown, it will need to be replaced for your furnace to work again. First things first, you need to locate your fuse box and search for the blown fuse. A blown fuse will normally appear discolored or maybe broken from the inside.

Once you have found the broken fuse, unscrew it, remove it, and throw it in the trash. Now you need to find a replacement that is the same size, type, and has the same amperage as the one you discarded.

Once you have replaced the fuse, it should get your restarted and back blowing warm air again.


Is there a problem with the fan itself? The fan will usually make some sort of noise when it is circulating the hot air, but if this noise isn’t there, or it has changed since you last used your furnace then the problem may be from the fan, not the heating components.

If the fan stops working on your electric furnace, you might have a burnt-out motor that you need to replace. The blower motor is the mechanism that runs the fan and sends air through the heating elements located inside the furnace. This warm air is then pushed out of the furnace and through the ventilation system and into your home.

If your blower motor is broken and you find your furnace blowing cold air, it will need to be replaced, and the best bet for that is to call a technician as it can be a complex job.

Overheated Furnace

An overheated furnace can cause many of the components located inside to break and stop working. In general, the best way to fix this is to take a systematic approach and check to see what parts of the furnace have been affected by the overheating and which have not. In general, repeated overheating can lead to failures in the filters, blower motor, high limit switch, and so on. Here are some steps you can follow to try and remedy the overheating: (If you are particularly not good at repairs then it is time to call a heating repair company who can make the necessary changes).

  • Change the filters
  • Check your vents for blockages
  • Inspect the evaporator coil and make sure it isn’t damaged or dirty
  • Check the blower motor fan (as mentioned earlier)

Leaking Ducts

leaking ductsLeaks in the ducts are a very common problem with electric furnaces. Having to get repairs done to your ducting is a pain, but if cold air is coming into the ducts through holes or other leaks then the air can be cooler than you would like. This defeats the purpose of having the furnace on.

If your ducts are accessible, you can check for any visible signs of damage to them. Check how old your ducting is, it could well be that after years of wear and tear they’re not functioning as they once were.

Typically, it’s better to leave duct repair work to the professionals as it requires specialist equipment and a considerable amount of skill to be done correctly. However, there are a couple of ways you can do it yourself if you fancy yourself as a handyman. Just be careful not to do more harm than good.

Firstly, you need to locate exactly where the leaks are coming from. Once you’ve found it, you need to cover it up with HVAC tape. This is a special type of tape that is specially designed for use in your ductwork. It’s much stronger than duct tape, so make sure you head out to the store to find the correct version. Once you have it, generously cover the area that is leaking with the tape and make sure no air can escape.

The second method is to use duct sealant, which is a pasty substance that is similar in viscosity to paint. You need to apply this to the cracks and gaps in your ductwork so it can dry and cover up the leaks. Once applied and dried, apply a water-based sealant to finish the job off.

Condensate line issues

Your condensate line is an exit route for the moisture and water that is collected by the evaporator coil inside your electric furnace. The evaporate works by removing humidity from the air and then converting it into water. This water then drains away into something called a condensate pan, which is subsequently drained away through a pipe and deposited somewhere outside your home.

Over time this line will begin to clog up with dirt and slime, and it will eventually make it very difficult for the water to pass through freely when this happens. The condensate line can become clogged, and your float switch will get tripped. This makes the system shut down.

If this happens, you need to unclog your condensate line so you can clear the way for the water to drain away from the pan. To do this, you can flush either a bleach or vinegar solution down the pipe and leave it for around thirty minutes. Once 30 minutes are up, you should flush water through the pipe to displace any clogs.

Problems at the fuel source 

If your furnace is now blowing hot air, this could indicate a problem at the fuel source. While this may seem obvious, it’s always worth checking to make sure there is enough fuel to power the furnace; otherwise, it will not function properly.

If you have an oil-powered furnace, is there sufficient oil in the tank? As we mentioned earlier, if you have a fully electric furnace, you need to make sure the circuit breakers are switched on, and the fuses are not blown. If they are, your system will not function.

Lastly, if you have a gas-powered furnace, you need to check to see if the gas valve supply is open. Sometimes the valve can accidentally get switched to the off position if somebody walks by and catches it. It may seem trivial, but a lot of technician callouts can be prevented by taking the time to check all of the basics first

Gas valve issues

Finally, if you have a gas furnace, several things can go wrong with the valve. As we just mentioned, sometimes the valve can be accidentally knocked into the off position, so check to see if that is the case before you continue troubleshooting.

If the gas valve is on, here are some things to look out for:

  • Are the wires to your gas valve faulty or frayed?
  • Does the flame stay lit for a few seconds then turn off?
  • Is the blower motor working slowly?
  • Can you smell excess gas?

If you answer yes to any of these questions, there is a strong chance that there is an issue with your gas valve. While you may be able to fix these issues yourself, it is highly unadvised. Gas leaks are extremely dangerous and pose a significant health and safety risk.

If you suspect there is an issue, please call an expert immediately and have them come out to deal with the issue ASAP.

Call a Professional

plumbing las vegas

If you’re still wondering “why is my heater blowing cold air?” then the chances are that you need to speak to a professional. If it isn’t something obvious like a fuse then you probably need a specialist to come in and help with the repair and get your home back up to the warmth you desire.

If you don’t know what you’re doing when it comes to repairs then there’s no point in trying your own repairs and making things worse. The best furnace repair technicians are very quick and can identify and fix the problem in no time, especially if it doesn’t involve the ducts of your home. It’s always worth discussing your problem with a pro to see if you need their help.

Business Name – Elite Plumbing, Heating & Air Conditioning

Address:  3085 E Post Rd, Las Vegas, NV 89120, United States

Phone Number: 702-263-2665


We Provide Expert Air Conditioning Services in Las Vegas, NV

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