I have an electric Whirpool dryer (Model: YLER7648DQ0). It was drying very well until a few weeks ago. Now it takes forever to dry most anything. I’ve checked the air flow and that seems good. I’ve also had it running with the door open and can see the heating element seems to be working, although I’m not sure how well. Any suggestions to look for before my wife blows a gasket??
A 7648 does not come up a YLER8648 does and may be close to your unit, see below.
http://www.appliancepartspros.com/partsearch/model.aspx?model_id=5141704
I’ve checked the air flow and that seems good.
I would try the following just to be sure the vent system is OK.
Undo the dryer from the exhaust
Run a load
If the load dries correctly then you have a vent problem.
Clean/check the vent system. Make sure the outside louvers open fully.
If you do not want lint in the house.
Take a pair of pantyhose, put one leg into the other and attach this to the dryer exhaust.
Leave enough room behind the dryer so it can blow out like a windsock.
Run a load.
Both the above will allow you to check the air flow and temp.
Also the above is NOT recommended for a gas dryer due to possible carbon monoxide problems
Also check/clean the blower wheel.
Sometimes the filter screen can get coated in fabric softener residue so also check it.
If unit is still not working correctly.
Check the heating coil
Unplug the unit and both wires to the coil.
Check it with a meter, should be around 10 to12 ohms.
Then check from each side of the coil to the case/frame, both should be infinite ohms (open). If not the coil may have broken and is touching the case. This can cause it to run with only part of the coil heating.
— Begin quote from denman;295504
A 7648 does not come up a YLER8648 does and may be close to your unit, see below.
Replacement parts for WHIRLPOOL YLER8648PW1 29" Electric Dryer | AppliancePartsPros.com
I’ve checked the air flow and that seems good.
I would try the following just to be sure the vent system is OK.
Undo the dryer from the exhaust
Run a load
If the load dries correctly then you have a vent problem.
Clean/check the vent system. Make sure the outside louvers open fully.
If you do not want lint in the house.
Take a pair of pantyhose, put one leg into the other and attach this to the dryer exhaust.
Leave enough room behind the dryer so it can blow out like a windsock.
Run a load.
Both the above will allow you to check the air flow and temp.
Also the above is NOT recommended for a gas dryer due to possible carbon monoxide problems
Also check/clean the blower wheel.
Sometimes the filter screen can get coated in fabric softener residue so also check it.
If unit is still not working correctly.
Check the heating coil
Unplug the unit and both wires to the coil.
Check it with a meter, should be around 10 to12 ohms.
Then check from each side of the coil to the case/frame, both should be infinite ohms (open). If not the coil may have broken and is touching the case. This can cause it to run with only part of the coil heating.
— End quote
Thanks for this.
Can one get to the coil, easily, without taking the whole machine apart?? Does the drum have to come out. It’s been awhile since I have had one of these babies apart.
Just remove the rear panel.
Well I found out what was wrong. I opened up the back and found the heating element was shot. A good chuck of the coils were broken. I guess it’s not good when peices start falling out!! 
I’m off to get new parts tomorrow. Thanks for all your help.