When your heating unit first kicks on, it's generally normal to notice the mild scent of dust and oil coming from the machine. But if you start to notice an unpleasant smell coming from your heating unit, it might mean that there's something wrong. Here are five potential causes of bad smells, plus details about when you should schedule heating repair services.

1) Clogged Filters

Filters are designed to capture odor-causing particles and keep them away from your living space. If the filters become too clogged, though, they can start to smell bad themselves. You may notice that your home's air smells stale, musty, or smoky. If this is the case, you will need to replace your filters right away. You may also need to have your heating unit serviced by a professional heating unit repair professional to make sure the clog is gone.

2) Overheated Motor

If your motor has been running too often or gets overheated, it might start to emit a burning smell. If you notice this smell, you should turn off your heating unit immediately and contact a company that offers heating repair services. Otherwise, you are at risk of serious problems such as sparks or even a fire in your home.

3) Leaking Gas

If your unit uses natural gas or propane, then leaks can be dangerous as well as smelly. If you suspect that there's a leak in your heating unit, shut it off and call a professional immediately. You may also need to evacuate your home, as inhaling the fumes from a gas leak can be dangerous.

4) Mold or Mildew

Mold and mildew will often produce musty smells that are difficult to ignore. If your heating unit has been idle for a long time, it could be especially prone to mold and mildew growth. Poor ventilation or having too much humidity in your home can also make mold or mildew start growing on the interior surfaces of your heater.

Don't delay if you see visible patches of mold or notice an unpleasant musty odor in your home. Reach out to a heating repair provider for suggestions on how to proceed.

5) Animals That Have Passed Away

Sometimes rodents or even household pets can get stuck in the ducts of your heating unit and pass away. If you notice a particularly foul smell coming from your heater, there's a chance that an animal is stuck somewhere inside. Don't try to remove the creature yourself. Instead, contact a heating repair professional for help with this type of problem and the others listed above.