The most common cause of this is a dirty/clogged vent system.

Clean your vent system and also make sure the outside louvers open fully.

Also you could try the following.
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.

Here are your parts
Replacement parts for WHIRLPOOL GEQ9800PW1 27" Electric Dryer | AppliancePartsPros.com

Here is the wiring diagram
http://www.servicematters.com/docs/wiring/Wiring%20Sheet%20-%208541831.pdf

[COLOR="Blue"]I tried this and the air flow is fine. However the air is blowing barely warm. So could it be the heating element?[/COLOR]
Yes it could be the cause.
Try the following
First try flipping the breaker off/on slowly a couple times. Sometimes you can loose half the line without actually tripping the breaker and the heating coil requires the full 240 volts.
If this does nothing.
Measure the voltage at the plug
L1 to L2 should be 240 volts
L1 to Neutral and L2 to Neutral, both should be 120 volts.
If OK
Unplug the unit and check the wires at the unit's terminal strip to ensure they are properly connected and none of them have burned off
If OK
Plug the unit in and check the voltage at the terminal strip. This is just in case you have a bad line cord. Be careful 240 volts is lethal.
If OK
Unplug the unit and both wires from the heating coil and check the heating coil.
Heating coil, should be 10 ohms approximately.Then check from each connection to the case/frame, both should be infinite ohms (open). If not you probably have a grounded element.

If the above is OK
Check your cycling thermostat. You will see that it has 4 wires. Two are the heater contacts, the other two are the internal heater (usually a smaller wire).
Remove one of these and tape it up so it cannot short to anything. Then plug the unit in and give it a try.
If it now works OK on high heat then someting is holding the internal heater on all the time.