Dryer is heating up, but
Here's a few things to check that most people can do on their own. Keep
in mind, that if you start taking the unit apart, you need to unplug the
unit first. We don't want anyone getting zapped!
1) Obvious
things first. If you have a propane gas dryer, make sure you are not out
of gas! Go to the tank, lift the lid, look at the % gauge. If it's
pointing at 5% or less, you may be empty or about to run out of gas.
Order a gas delivery.
2) Another obvious tip. Check your lint
filter. It may be so clogged that your dryer can't breathe. Clean it.
Using a flashlight, look down into with the filter opening and see if
there is a lot of lint still inside. If so, try using a small vacuum
attachment and clean out lint. This applies to both gas and
electric dryers.
3) Most gas dryers have either a small
access panel in the front or at the very least, a peep hole. Open the
panel or pop out the plastic peep hole cover so you can view the
igniter. Turn on the dryer and watch for orange glow at the burner. If
it does not glow, it will not light the gas burner. You may have a
broken igniter and will need to replace it or have a new one installed. If
you do it yourself, be sure to unplug the dryer and do not touch the
very fragile ceramic piece of the igniter. You can confirm it is
broken by locating the broken piece below where it is attached or noting
it is missing a piece of ceramic on the igniter.
4) This
tip applies to both gas and electric models. Another thing you
can do is check for blockage in your vent. Unplug the dryer, and pull
the unit out as far as you can to get access to the back of the unit. Be
careful not to step on or kink the gasline. Pull the venting off the
back of the dryer. There is usually a squeeze clamp holding it on. Clean
out lint in dryer and from within the vent tube. Some cheap
venting are made of expandable plastic or aluminum and can get squished
to the point they restrict air flow. Make sure your vent is not
collapsed and doesn't get squished when you push the unit back. Once
you have cleaned and reassembled it, plug it in, turn on the dryer and
watch for ignition. If it lights, go outside to the vent cap and check
for lint there and make sure your vent flap opens with the hot air
flowing out. Clean and adjust as necessary. If you have a long vent tube
like I have on mine, then you should clean it out annually. I use a
wind-up toilet snake and crank it around knocking lint loose from the
walls of the vent. I can always tell when it needs to be cleaned again,
when clothes no longer get dried in the first cycle. If you are unsure
of, or unable to perform this task, then you'll need to hire a
repairman.
Anyway, these are just the easy, quick fixes that
most homeowners can perform on their own. If none of these solve the
problem, you will need to troubleshoot further or hire a repairman. Hope
this helps.Douglas
The thermal fuse is what is blown. Replace the limit that comes with it too. That limit take a beating when that blower wears out and starts slipping. 
