Most of the concerns or problems that you will encounter with your compost pile are minor and relatively easy to rectify.
They involve rotating the collection more, adjusting the material, you are putting in, and layering enough brown food for the top layer. The issue of your pile not heating up will require more investigation.
The first thing to consider when your pile won’t heat up (when you are using the hot or active compost method) is if you have enough green and brown food added. If your piles new, this will take time. But if you have an established collection that won’t heat up, either your pile is too large, or you are not adding enough to start the decomposing process.
Another reason your compost pile may not be heating up is the presence of too much brown food. If you have added a lot of leaves or other brown matter (high in carbon), put in more green food that is high in nitrogen. The presence of carbon and nitrogen is necessary for the correct ratio (2:1).
If your pile is too dry, this will prevent it from getting hot also. The microbes need a moist environment to do their work. Add just enough water to make the pile damp or add wet green food such as vegetable or fruit waste and grass clippings.
When you are using the hot composting method, remember to keep all matter smaller than three inches. This will speed up the process and ensure all thing is broken up evenly. If the mixture has large pieces, it can delay the heating up process.
Weather is a factor too. If you are concerned that your compost is not heating up and it is fall or winter and most likely, it is too cold for the process to start. You can try insulating your compost pile or wait for the spring.