Clothes dryer Open dryer door there is heat but clothes are not drying.

IT is the timer. If electronic needs to replace the board. If dial type, needs the timer

use your dryer on air dry only (not heat dry) run about 2 min. check if your dryer is hot, that is heating element is short to ground and if your dryer is cold, check your dryer air venting system. (open the door if you see lint on door panel, it is a sing of bad air flow, it is dangerous to fire) hope its help.

if you have it on time dry and it doesn't count down the timer is bad but it should stop when you open the door unless you have a broken door switch too,just open the door and push in on the switch with your finger,it should make a clicking sound,if not the door switch is also broke,if you have the timer on auto or more or less then it won't move without heat.on auto the heat comes on when the dryer reaches temp. the heat shuts off and the timer will advance a little,then the heat starts again and the timer stops,it will do this until the clothes are dry by using a sensor instead of time.

You will need to check all the duct work for lint buildup. This is the reason clothes won't dry or take a few cycles to dry.

Overloading
1. One of the simplest problems to remedy could simply be that you are putting too many items inside the machine during the drying cycle. Avoid overloading your dryer, as this might cause your dryer to work extra hard to dry your clothing, extending the length of the dry cycle.
Wrong Heat Setting
2. A common issue with clothes dryers could be the wrong heat setting. Most home dryers feature several settings, from low heat settings to high heat and permanent press. Be sure the setting you choose is right for your needs. Another setting to check is the load size of your dryer. If you are drying a large amount of clothes, be sure the setting for large loads on high heat is selected. Choosing the wrong heat setting or load size can cause your clothes and linens to take longer to dry.
Lint Trap
3. One of the simplest fixes for drying issues might just be that your lint trap is clogged. Each time you use your dryer, lint will form in the trap. If the lint trap and vents are full, this could block air going into your dryer and slow down if not completely stop the drying process. After you use your dryer, remove this lint trap and empty it fully. Even if the lint trap is full, your other dryer vents might be clogged as well.
Clogged Vents
4. If your clothes are in the dryer for a long amount of time, but still not drying, the reason for this could be a clogged vent. A sign that your vent is clogged is if your clothes are warm or hot to the touch after sitting in the dryer, but still damp. To unclog your dryer vent, you may need professional assistance. This is especially necessary if your dryer vent leading out of the house is particularly long.
Heat Source
5. If the dryer is not getting enough heat to dry your clothes,something could be wrong with the heating system. After the drying cycle, touch your clothes to see if they are warm. If not, this means that the heating mechanism is malfunctioning. It will need to be repaired or replaced by a professional.

make sure that all the seals are ok, door,front and back drum seal, blower housing seal(inside dryer). also consider that depending on washer type if you overload or have a worn drive belt in washer it will take twice the time to dry. also make sure that the dryer drum tumble. open door,press door switch and start dryer to see if drum turn. lastly disconnect vent pipe behind dryer and dry a load. if it dry ok then you have a partial blockage. you can also have a weak heating element.

check your ignitor id make sure the vents cleaned as well

Is yours the gas model? If so I need you to look for some things. Open back door panel and see if while trying to light the igniter is glowing orange. Sea Breeze

You have a venting problem and air is not leaving. Its either kinked or clogged.

remove the ventin from behind the unit you need to replace and or clean your vent !!!!!