I have a whirlpool dryer, model ler4634jq1, and it will not heat. I have replaced the top thermostat on the heating element as well as the heating element. I check the fuses of the other thermostat, the thermal fuse and also the cycle thermostat and they were fine. Not sure why it isn't heating. Any help please?

Have you tested your power to see if you are actually getting 240 vac to the unit?

These driers will do that when the lint builds up like concrete on the inside of the air ducts. They blow the main safety to keep it from burning the house down. Halfway cleaning it will not work. If the fuse blows you need to totally tear it down and scrape out and wash all of the parts except the motor, which you vacuum out. You can go to YouTube to see videos on how to take it apart, but do a very good job or it will fail again quickly. I would get a new belt and change it while you have it apart and get some white lithium grease and grease any bearings you find. You need to clean out a drier every two years, at least, according to the manual. You just unplug the wires from the sensors and remove ductwork that they are attached on and clean the entire thing with soap and water. Make sure you go all through the dryer and get all parts like the blower fan and housing, vacuum out the motor well and clean the exhaust line and the outside boot as the screen gets stopped up. Mark all wires you unplug so you know where they go. This is an easier job than you would think. Make sure to clean around all of the sensors, too, because when they cannot sense the dryer will not work, plus the burning lint deposits will burn down your house. The blown safety is like a fuse and located near the elements, but there are several strung together in series, so you have to go from one to the other until you find the one that has infinite resistance. You will need a meter to find the safety that is blown . Replace the belt which you can get the same place that sells a new safety. See: Dryer vent cleaning prevents fires - YouTube and: Cleaning out a dryer with top lint cleanout - YouTube
Cleaning out a dryer: By a woman 2 of 2 - YouTube
Manuals: https://dl.dropboxusercontent.com/u/...yer-manual.pdf
https://dl.dropboxusercontent.com/u/...e%20Manual.pdf
https://dl.dropboxusercontent.com/u/...e%20Manual.pdf
https://dl.dropboxusercontent.com/u/...l%20Dryers.zip
https://dl.dropboxusercontent.com/u/...%20Manuals.zip
I very much doubt that any thermostats needed replacing, but to test one you boil water and clip the leads on the terminals and dip the thermostat in the water and it should go from zero ohms (closed) to infinity (open). You need to learn how to read a wiring diagram and use a meter. Never use the meter set to ohms with the power on, and watch out for capacitors because they store electricity at around 300+ volts at times. ALWAYS short out a capacitor before testing it or it can burn out your meter, blow the fuse, or kill you. Turn off power before testing on the "ohms" setting. You also need to check to see how many volts you have, so with the meter set to "volts," (the setting you should always start with even when testing for ohms to make sure there is no power) test the dryer receptacle and make sure you have 240 volts across the two hot legs and 120 volts from each one to ground. Then take the cover off the breaker panel and with the correct screwdriver tighten the screws on all of the breakers as they will loosen over time and cause appliances and wires to burn. Do the same on the receptacle. Use a screwdriver, like a Klein insulated shaft screwdriver, to tighten the screws. Buy several sizes so you always have the biggest one to fit the screws snuggly. Make sure you buy screwdrivers made for electrical work with round, insulated shafts to keep from breaking a breaker as a square shaft one will. Then follow the safeties through the dryer starting with the door switch by taking one wire loose from each one before testing. You will find the problem that way. You may also take a hard look at the high limit switch which should have opened before the fused safety that blew. Frequently the high limit's contacts get welded shut and this cases the expensive safety to blow out. Buy a high limit ten degrees below the safety. The temperatures are stamped on the mounting flanges.