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15 Reasons Why Your Compost Tumbler is not Getting Hot

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Do you have a compost tumbler at your home? Is the tumbler serving you well, or are you experiencing problems with it not getting hot? If you own a compost tumbler that is not getting hot, this article will show you 15 reasons why your compost tumbler is not getting hot.

There are many factors why compost tumblers do not get hot, due to the inappropriate amounts of moisture, air, nitrogen, carbon, and microbial life. Altering the ratios of each of these components can significantly improve your results.

One of the main reasons for a compost tumbler not heating up could be its potential size and design. In that case, I wrote an article that goes through 10 of the best compost tumblers, which explains all the features and benefits of each and makes a top three recommendations. Check It Out Here!

Having owned a compost tumbler myself, I found that not only was it difficult to heat up but I also more often or not ended up with a smelly, slimy mess or compost that didn’t break down. If this is your experience, then make sure to read on as I provide you with 15 reasons why your compost tumbler is not heating up at home.

1. Lack of Insulation on your Compost Tumbler

Your compost tumbler fails to heat, probably due to poor insulation of the tumblers. Proper insulation promotes the efficiency of the compost tumblers, thus increasing performance. In this case, performance can only improve by fitting an insulated, new, and effective compost tumbler.

Another reason why your rotary compost tumbler fails to generate heat is because of poor insulation in its thin tumbler walls. This design sees a lot of heat escaping, thus straining the compost and cannot heat efficiently. Such a phenomenon is common mainly during the winter season when there are low temperatures outdoors.

2. Adding Large Material in the Compost Tumbler

If your compost contains large materials that have not been cut, then this might be the reason your rotary compost tumbler fails to heat. You should check out if the material in the tumbler has been ground, chopped, or shredded into smaller particles to improve performance.

Breaking the matter into smaller particles is vital in increasing the surface area for greater availability to microbes to break the waste quickly. Microbial activities intensify when the availability of material for feeding by bacteria is high due to composting.

3. Ensuring The Correct Starting Mix on your Compost Tumbler

When using a compost tumbler, it is necessary to assess the starting mix to ensure it has the correct matter sizes. Lack of starting material optimization is one of the probable reasons your rotary compost tumbler fails to heat.

To successfully create compost in your tumbler, You need to ensure that you have the right balance of greens and brown materials, they are all shredded to be small as possible and you have many different ingredients which will produce higher quality compost.

4. Incorrect Moisture Levels on your Compost Tumbler

Have you ever thought about checking the moisture levels of your compost tumbler? There is a significant correlation between the levels of moisture in the compost tumbler and the material therein. If the correlation is far apart, this can be an apparent reason why the rotary compost bin is not getting hot.

If you never have, then you should consider doing it from time to time. The aim is to determine how much dry or wet the mixture is to establish the correct ratio for the start of the home composition. Green materials in the tumbler generate nitrogen, while brown ones produce carbon.

The presence of little green matter in the tumbler makes the pile overly wet and leak moisture. On the other hand, if the brown materials are more, the compost pile will be dry. Decomposition occurs in cooler temperatures and slowly under high carbon material.

5. Type of Compost Tumbler Material

The content of the compost tumbler might be the reason your rotary compost bin is not getting hot. While some materials break down easily and faster, others consume relatively more time. For instance, requiring more time to decompose, microbes face the difficult task of splitting the composting materials.

The subsequent effect in this scenario is that your rotary compost bin will not get hot, and the pile will heat slowly.

6. Absence of an Accelerator in your Compost Tumbler

Your rotary compost bin is not getting hot due to the lack of a compost accelerator. To increase efficiency and ensure your compost tumbler gets hot, you should complement the container full of a material mix with a compost accelerator. The primary objective of having an accelerator in the bin material is to intensify microbial actions in the dung.

Accelerators can be purchased or can even be from ingredients you already possess. Add part of a premade compost from an earlier batch, worm castings, garden soil, urine, or high nitrogen teas to start the process.

Information is like compost; It does no good unless you spread it around!

Eliot Colman

7. Ensure The Compost Tumbler Is Turned Enough For Good Airation

Pile and any other compost tumbler material require proper handling by rotating the tumbler. However, if this is carried out inappropriately, it can be the reason your rotary compost bin is not getting hot.

Whereas you should ensure you regularly turn your pile to ensure circulation of oxygen, you face a risk of destroying the delicate bacterial web being forming fully.

The consequence is that the compost tumbler experiences heat dissipation besides hampering microbial activities. It would be best to use a compost thermometer for hot composting to avoid the risks of rotary tumbler failing to attain maximum heat.

8. Selecting The Right Location For Your Compost Tumbler

Your rotary tumbler is not heating because you have your tumbler at an undesirable location. It would be best if you strived to find a better area to maximize the compost tumbler and enhance its performance. For instance, you should place the tumbler where there is adequate access to the sun.

Typically, the external temperature of the compost tumbler significantly affects how much a compost gets hot. That is why it is easier to realize hot composting during summer than during winter. It would be best if you also positioned the compost tumbler away from the direction of the wind to ensure it preserves heat in addition to insulating the bin.

9. Adding Too Much Nitrogen To The Compost Tumbler

Your compost tumbler’s pile can heat up faster if the inside conditions have high nitrogen content. If the nitrogen to carbon ratio is suitable, then your compost tumbler will get hot faster.

The per volume ratio of nitrogen to carbon that is greens to browns should be one against two.

The green component in the compost tumbler feeds microorganisms. Balancing the ratios well ensure that microorganism and bacteria obtain the best conditions to function in the tumbler to generate compost.

10. Adding The Wrong Ingredients To The Tumbler

When the wrong materials are added to a compost tumbler, the success rate of its heating is significantly less. Putting cooked foods such as chunks of pork, beef, and chicken meat makes it hard to break down and doesn’t help the heating process. However, shredding this ingredient into tiny portions will significantly help the breakdown process.

Naturally, chunky components will take more time to compost in a compost tumbler. Therefore, the reason for your rotary compost bin not getting hot relies on the portions of the ingredients.

11. Absence of Enough Nitrogen in your Compost Tumbler

Usually, it is a difficult task to add greens into the tumbler as high-nitrogen overloads. If your compost tumbler fails to heat, then it is highly likely that the nitrogen content inside is low.

To solve this challenge, you need to increase the nitrogen levels inside the compost tumbler by adding greens. If the compost starts smelling and becomes slimy, that indicates that the added greens are too many.

Mixing grass clippings, kitchen waste, and woody material is the best combination because they will easily compact and wet to curb airflow. When you use different sizes of materials in the compost tumbler, air pockets develop. To prevent your compost tumbler from failing to heat, dump stalks, twigs, hay, and stalks.

12. Using Old Compost Batches with your Tumbler

Efforts of decomposing old compost batches previously put in a pile can make your tumbler fail to get hot. The old batches could have lost their entire heating-up capacity. However, the other probable cause of your rotary compost bin not getting hot relies on messed proportions.

This challenge stands regardless of whether you used new batches. Decomposing old matter without a precise material ratio makes it difficult to get accurate results, and therefore, your compost tumbler fails to work.

13. Too Dry or Too Wet Compost Materials

Your rotary compost bin is not getting hot because the compost material is either too dry or wet. It makes it impossible for the compost to get hot. When the pile is too wet, and the air inside the tumbler is too low, then the compost will become too wet.

Drying it requires removing the entire compost content for spreading. Drying compost material happens if brown material is too much while water is not enough. Compost troubleshooting requires you to make the compost texture spongy by adding more water or fresh animal manure to the tumbler.

14. Lack of Enough Oxygen in your Compost Tumbler

The absence of adequate oxygen in your compost pile can make your rotary compost bin not get hot. Lack of enough oxygen in the tumbler starves the microbes, making it difficult to break down the organic material in a pile.

Despite the limited air condition in the tumbler, decomposition can still progress even though at a slower speed. Typically, anaerobic microbes will slowly continue decomposing the pile. When the tumbler’s oxygen level is low, the tumbler will get hot slowly, making the pile smell and the temperatures reduce.

According to the University of Georgia, microbes require enough oxygen to crumble carbon-based waste material efficiently.

15. Absence of Microbes

Your rotary compost bin not getting hot can be due to the lack of microbes in the tumbler. Apart from performing the decomposition function in the tumbler, microbes also help in pile heating. After the microbes decompose the organic material, heat is produced, which further makes the tumbler hot.

To ensure enough microbes are in the tumbler, you can add ordinary garden soil and mix it with the pile. Microbes are always found in the ground, meaning the composition process will hasten. -Understanding how microbes populate your compost.

The University of Missouri establishes that heating up occurs between one and four weeks when all the compost tumbler and pile conditions are correct.

FAQ’s On Reasons your Compost Tumbler Is Not Getting Hot

Other Forms Of Composting Compared to Compost Tumblers

There are other forms of composting other than compost tumblers that are also perfect for making compost at home, such as:


If you are an avid gardener having a compost tumbler is a fantastic way to create your organic compost using your waste, it helps decompose waste quickly. It is a cheaper alternative to compost bought from stores.

If you are having trouble getting your compost tumbler hot, understanding different conditions and determining factors that affect the heat generation on your compost tumbler is a must.

I hope this article has answered that question for you. If you want to learn more about composting or other gardening tasks, consider subscribing below or entering a search term in the search bar above for another article.