furnace short cycling fix

Furnace Short Cycling – Troubleshooting

When you purchase a furnace for your home, it is important to understand some of the common issues. That way, when something happens, you can fix it right away, preventing any further damage. Keep in mind that if there is anything wrong with your HVAC system, there could be multiple causes. To solve it, you’ll need to perform a thorough diagnosis with the information we will provide in this article.

Here we will focus on the main issue you will encounter: electric furnace short cycling. The first thing you need to know is how to identify this problem. When HVAC is short-cycling, the appliance will turn on and off suddenly. This will last a few seconds between cycles. That’s why you will notice bursts of activity throughout the day. 

If your electric furnace is short cycling, then, there could be a minor malfunction with your appliance or a major problem. Below we will cover some of the probable causes and how you can fix them without calling a technician.

6 reasons your HVAC is short cycling

We are going to start with the problems that you can easily solve. Then, we are going to move on to the deep damages that can cause you a lot of money. But, if you know how to identify the issues on time, you can avoid the worst-case scenario.

1. Dirty filter

Having a dirty air filter is not only dangerous for your health, but it will also damage your HVAC system. In case you have a clogged filter, this will reduce the airflow. This means your furnace will warm up and shut off. As a result, your HVAC will have several short cycles.

The only way to fix this would be to change your filter once a month. This can be expensive, however, it is the best thing you can do, especially if you have kids with allergies at home. If you want to wait longer, then you will have to check it every month to know when it’s time for a new one. Keep in mind you can only extend the lifespan of your filter up to six months.

To make sure you purchase the right filter at the store, always check your user manual first. If you have any questions about replacing your filter, it is better to ask a professional.

2. Damaged flame sensor

The flame sensor is the part of your HVAC system that makes sure the gas valve fires. This is extremely important since it will also ensure there is no gas pumping into your home preventing a fire. When the sensor doesn’t detect the flame, then, as a protective measure, it will shut down the gas valve. 

Even when you have a damaged flame sensor, it might work sometimes. However, this is dangerous since you won’t have a protection mechanism to prevent a gas leak. If you believe this is the problem, then you will need to clean or replace the sensor. In this case, we will advise you to contact a professional for the repair. 

3. Oversized system

Sometimes homeowners might wonder why their HVAC is short cycling, even when there is nothing wrong with the appliance. For this instance, it is crucial to consider if the furnace that you have is oversized. If you have an overpowered system, chances are it warms up your home too quickly. However, this will happen unevenly. That’s why to maintain the temperature inside your house the furnace will do several short cycles.

If you think this is the problem, then you will have to call a professional technician. They are the only ones that have all the necessary equipment to evaluate your system. Then, they will tell you if it will be better to replace it.

4. Blocked exhaust vent

Your exhaust vent is what carries the carbon monoxide. This is a crucial function when it comes to your HVAC system since this gas can be deadly. If your exhaust vents are blocked, this might be the reason the electric furnace is short cycling. The danger of this situation is that if the gas doesn’t have a way out, it could leak into your home.

There are several reasons you might have a blocked vent, including bird’s nest, animals, beehive, snow, or ice. You will know if this is the issue with your HVAC since the system will overheat and short cycle from one to five minutes.

The only solution to this problem is going up to the roof and cleaning the furnace vent. Keep in mind that you might have to call animal control.

5. Faulty blower motor

When your furnace blower is short cycling, the air won’t circulate properly. As a result, your HVAC system will overheat. Then, to prevent any further damage, the switch limit will turn off your air conditioner. Usually, when this is the problem, you will hear a distinctive sound before the motor fails. 

If you want to fix a furnace blower short cycling, then you will need to replace it. Today, a blower motor replacement can cost up to $500. However, it is better to speak with a professional since it might be time to purchase an entirely new system. 

6. Thermostat issues

If you have decided to install your HVAC system without any help, then your thermostat might be in the wrong place. Sometimes homeowners think that their DIY installation was perfect, but they don’t realize there are several factors to keep in mind. For instance, when placing your thermostat it should not be near any heat source or direct sunlight. If this happens, the thermostat will quickly warm up and shut down your furnace.

In the same way, the thermostat should not be close to a door or window since it will cool down. It is also crucial to test if your thermostat is working, this might involve handling wires. That’s why we will recommend you to call a professional.

Finally, it is important to choose a new place for the thermostat and make sure you switch it to the right place when the new season starts.

Now, you know how to fix your HVAC short cycling, in case you need further assistance, call your provider. 

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