Have to replace broken belt on a whirlpool awz 7813 tumble dryer and wondered what way the belt runs around tensioners

You may want to contact a professional that will have the diagrams for your machine online. there are some here or you can go to another site. like (Just answer.) Be more specific about your problem. It can be fixed . There's no worries.

Are you saying that it does not heat up either ?In addition with not tumbling clockwise ?

Disconnect the dryer first. You can remove the top and front of the dryer to check to see what is happening. If it does not heat . You may need to replace the temperature control relay. If that does not work , the heating elements themselves may need to be replaced.

For the tumbling problem, they also have relay switches that go out.
BUT, if it is tumbling to one side and keeps tumbling then that will probably be enough to dry your clothes. As long as it is not too heavily loaded.

It sounds like it is the belt. When the dryer heats up the belt expands a little and when it gets wore out, the tensioner doesn't have enough spring to keep it tight. It might work a little when it's cold before the belt expands.
This belt should work for your dryer but verify the length.
http://www.amazon.com/Whirlpool-341241-Dryer-Drum-Belt/dp/B00DM8J15C/ref=sr_1_fkmr0_2?ie=UTF8&qid=1395071968&sr=8-2-fkmr0&keywords=whirlpool+awz121+belt

Here is a helpful Youtube video on how to do the repair.
http://www.youtube.com/watch?v=GzYmoS9brMY

Here is a link to the Service Manual
http://elektrotanya.com/whirlpool_awz121.pdf/download.html

The bottom of this link shows some typical ways a belt runs past a tension wheel and links for your dryer. If you replace yours I would recommend taking a couple pictures before removing the old one so you can refer to them when installing the new one.
http://www.repairclinic.com/Dryer-Belt-Diagrams

Unplug the unit and take the top with the screws holding the lid on. Take a look at all of the wires on the top of the machine. You might notice broken/burnt wires on the safeties that are close to or that directly activate the heating element located in the blower housing located at the top of this washer/dryer condensing unit.

It sounds like your drive belt might be broken you can get a new one if you go to www.repairclinic.com enter in your model number and it should cost around 9$ the other possibility is the tension pulley or if it doesn't sound like your motor is running but most likely the drive belt .

it will either be you element or the thermostats that have failed.

If you have seen belts in cars, there is something to remove the slack (spring loaded). Its similar to dryers,, the dryer belt goes around the drum and the motor (obviously). from there, there is a wheel that connects to the base. It is spring loaded and takes the slack off the belt. If YOU took it apart (recently), hold the wheel/spring assembly in your hands as it would be positioned if it were screwed into the chassis. Move the wheel to get an idea what direction the spring pulls.

I hope this helped a little.

how do i clean my heat exchanger on the whirlpool awz 7913 condenser tumble dryer?

how do i replace my belt on my tumble dryer

A broken belt is very common. If you hear the motor running, that's probably it. The dryer must be taken all apart to replace the belt. Hopefully instructions will come with the new belt. Routing the belt over the motor shaft and around the tensioner is always a challenge.

pull the front off then put the belt around the drum then pull the idler pulley back to put tension on it and put the belt around the motor pulley let the idler pulley back against the belt to keep it tight replace the front and your done