A clogged clothes dryer vent can lead to various problems and symptoms that may affect the performance of your dryer and even pose safety hazards.

Here are some common symptoms of a clogged dryer vent:

1. Longer Drying Times: One of the most noticeable signs is that your clothes take much longer to dry than usual. If it used to take 30-40 minutes to dry a load of laundry, and now it's taking an hour or more, this could be due to a clogged vent.

2. Dryer showing an Error or Fault Code. D80,D90,D95 or AF ( these are just a few of the codes). 

3. Excessive Heat: The dryer may become excessively hot during the drying cycle. Overheating can not only damage your clothes but also pose a fire risk.

4. Clothes Are Hot to the Touch: When you remove clothes from the dryer, they feel hot to the touch, indicating that the dryer is not effectively venting heat and moisture.

5. Musty Smell: A clogged vent can cause moisture to accumulate in the dryer, leading to a musty or moldy odor in both the dryer and your clothes.

6. Excessive Lint Buildup: You may notice an increase in lint collecting in the lint trap and around the dryer drum, even after cleaning it regularly.

7. Reduced Airflow: If you feel little to no airflow from the vent outside while the dryer is running, it's a sign that something is blocking the airflow, possibly a clog.

8. Hot Dryer Exterior: The exterior of the dryer itself may become hot to the touch, which is a safety concern.

9. Increased Energy Bills: A clogged vent can make your dryer work harder and longer, leading to higher energy bills. The dryer could use up to 30% more energy.

10. Dryer Shuts Off Prematurely: Some dryers have safety mechanisms that shut off the dryer if it overheats. If your dryer keeps shutting off before the cycle is complete, it might be due to a clogged vent causing overheating.

11. Burning Smell: In severe cases, a clogged vent can cause the lint inside the dryer to overheat and produce a burning smell. This is a critical safety concern and should be addressed immediately.

12. Dryer Vent Hood Blockage: Check the vent hood (the exterior opening of the vent) outside your home. If you notice debris, lint, or other obstructions around the vent hood, it's a clear sign that the vent is clogged.

It's important to address a clogged dryer vent promptly to ensure the safety and efficiency of your dryer. Regularly cleaning the lint trap and scheduling professional vent cleaning as needed can help prevent these issues. A clogged dryer vent not only reduces the effectiveness of your dryer but also poses a fire hazard, so it's essential to address it promptly.