Is Furnace Short Cycling Dangerous? (We Have The Answer)

Benjamin Wright
by Benjamin Wright

When the weather begins to cool off furnaces start to warm up. Most of the time, the sound of furnaces waking from hibernation reminds as above spending the cold nights of winter in the warmth and security of our homes. Sometimes, however, the sounds were here are a bit less comforting.

Yes, furnace short cycling is dangerous. This is because the short cycling can lead to carbon monoxide poisoning, fires, and other potentially dangerous situations that can threaten your life or wellbeing. You will need to find the cause of the short cycling so that you can fix your furnace before using again.

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Why Furnaces Short Cycle

When you are faced with the problem of a furnace short cycling, it can often be difficult to determine the exact source of the problem. there are many things that can cause furnaces to short cycle. To find out why your furnace is short cycling, some troubleshooting may be in order. Here are some of the first places that you can check.

Thermostat Improperly Installed

A very common cause of furnace short cycling is having a thermostat installed in the wrong place. The idea when installing a furnace thermostat is to place the thermostat in an area that gets plenty of airflow. The placement should also be in a location that has a good average temperature for the house.

Placing the thermostat in hallways are large rooms is usually preferred to locations that are in tight spaces with limited airflow. You should also be mindful of heat sources near the thermostat.

When furnace thermostats are installed near lights, registers, or in locations that get direct sunlight, the excess heat can trigger the shut-off function of the furnace. heat sources can easily keep the furnace from running long enough to provide ample heating for a home.

Furnace Size

Another important consideration when narrowing down possible causes of furnace short cycling is the furnace size. When sized appropriately, heat cycles are long and gradual. When furnaces are too small for the home they are heating, it is common to see furnaces running 24/7.

On the other hand, when furnaces are too large or a home, the air inside the space heats up so quickly that the furnace only has to run for a few minutes before triggering the thermostat. When this happens there are noticeable swings in temperature on an ongoing basis.

Clogged Filter

Clogged filters on the air intake on a furnace can also cause short cycling. When this is the case, short cycles will run up to five minutes before turning off.

the reason clogged filters cause short cycling on furnaces is because they limit the amount of fresh air being pulled into the furnace. Without fresh, cool air, the furnace is unable to maintain a safe operating temperature. when furnaces become too hot, an auto shut off switch is triggered.

To avoid this problem, all that is needed is to regularly check and clean the filters on the furnace. doing so will not only make your furnace safer, but also more efficient.

Flame Rod

The flame rod is yet another possible cause of a furnace short cycling. the flame rod determines whether the gas being pumped into the furnace is, in fact, burning. When the flame rod is damaged, corroded, or broken, it fails to get an accurate read on the gas flow and resulting flame going into the furnace.

The easiest way to check and see if the flame rod is to blame for the problem is too open the furnace up and observe the furnace firing. If the furnace shuts off within seconds of the furnace firing, there is a good chance that the flame rod is t root of the problem. Cleaning or replacement may be required.

Heat Grates

If you have too many heat grates closed throughout your house, overheating in your furnace can occur. When the furnace overheats, it automatically shuts its self off.

The general rule of thumb is that at least 60 to 80% of all the heat vents in your home should be open. This will allow ample hot air to flow out of the furnace.

Faulty Exhaust

One of the most common causes of a short cycling furnace is a blocked exhaust flue. exhaust flues can become blocked for many reasons, including bird nests, beehives, as well as dry leaves during the autumn months.

Maintaining a clear exhaust flue will help your furnace run smoothly and safely. In fact, where safety is concerned, having a blocked exhaust flew can become incredibly dangerous.

When Short Cycling is Dangerous

As you can see from the example above, some of the causes for short cycling can lead to dangerous situations. It is important to know when your furnace presents a safety concern and when it does not.

While the furnace itself is designed with several safety features in place, there are some situations when you should be concerned.

Overheating (Hot Parts)

In many cases, when furnace is short cycle, they go through periods of extreme heat before cooling down again. it is often the case that the furnace is shutting itself off because of extreme temperatures. When this happens, there are parts of the furnace that can cause serious burns if touched.

For that reason, it is always better to allow the furnace to cool down for a sufficient amount of time before trying to troubleshoot or fix the issue of short cycling.

Carbon Monoxide

Carbon monoxide poisoning is yet another danger that came come from a furnace that is short cycling. When a blockage exists within the exhaust blue, for example, there is nowhere for the expended carbon monoxide to escape to other than your home.

When this problem goes unchecked, it can pose serious health risks. Therefore, if your furnace is short cycling always be sure to check the exhaust as part of your regular maintenance and troubleshooting tasks.

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Related Questions

How do I know if my furnace s short cycling?

Furnaces run on cycles. They are active when the thermostat has a low reading and they turn off when the thermostat registers a create determined temperature. if your furnace is short cycling, you will notice that the warm cycle is either too short, or that’s the entire on off-cycle occurs too frequently.Short cycling happens because of the furnace’s safety mechanisms. So, when things are not working as they should, the furnace will not cycle properly. This is generally apparent by observing the length of each cycle. If the cycle seems too short it probably is.

How much does it cost to repair a furnace that short cycles?

The costs associated with furnace repair range from $50 to $500. Depending on the source of the problem, as well as which replacement parts you will need, the prices can vary quite a bit.In most cases, the cost of repairing your furnace short-cycle issues or on the low side. As short cycling in a furnace is generally caused by a lack of airflow and proper maintenance, simply rectifying those issues can quickly solve the problem.

Benjamin Wright
Benjamin Wright

Benjamin is a proud homeowner who loves to write about DIY projects and home improvement projects. Traveling, perfecting his home, and spending time with his family are just a few of the many things that keep him inspired.

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