Good morning, I am hoping you can provide me with some insight. I have an Electric Whirlpool Dryer Model # LER7646DQ0. There is no heat anymore…it just spins and never heats up.
This has happened before and my husband replaced the part. We can not remember is it was the heating element or the thermostat that we replaced. Would you have an idea based on the problem? 
You posted on the washer page, so this is why there has probably been a delay in responding to you.
You need to check continuity on the thermostats, thermal cut-off’s and thermal fuse. The one(s) without continuity is the one to replace. If you click on your model number you will be taken to the pages with parts on them and you can order the right part(s). Be sure and disconnect power to the dryer before working on it.
If all of these check out, the next step is to check your heating element.
If this has happened before it indicates a potential problem with your venting. When you have the dryer open clean out all areas, with compressed air if available, with a vac and cloths if not. Pay particular attention to the air duct/vent and make sure it is absolutely unobstructed.
Good luck, and please post how it turns out.