Dryer has no heat--even though lint filter and heat exchanger are clean; the light is also off, but the tumbler turns normally

Make sure the dryer exhaust tube is clear of lint and not kinked. Next thing I would check are the thermal fuse and thermostat. Check this out: http://removeandreplace.com/2013/09/21/fix-clothes-dryer-heating-drying-clothing/

Is it gas dryer?

If it is might be problem with the heat exchanger, Water is one of the by products of combustion.

By chance do you have a Carbon Monoxide sensor?

Easy way to tell if a cracked heat exchanger is the problem.

Other thought I have is the dryer heating up when its drying, if the heater isn't working and you are throwing wet clothes in there that could be part of the issue.

a couple thoughts anyways

I’m happy to assist further over the phone at https://www.6ya.com/expert/robert_54ae41aaaffbab00

Instructions

Dryer Does Not Turn On
1

Ensure that the dryer's power supply cord is firmly plugged into an electrical outlet.
2

Inspect the structure's fuse box for a tripped fuse. Each fuse is assigned a single "On/Off" switch. If any fuse switch is in the "Off" position, flip that switch to the "On" position. If the problem persists, contact a professional electrician.

3

Press the "Start/Stop" button on the left side of the dryer's control panel.
4

Close the dryer door firmly so that the door clicks into place. The dryer will not operate if the door is not shut.
Lint Filter
5

Clean the lint filter. Twist the program selector knob on the control panel to the "Off" position, then open the dryer door. Pull the lint filter out of the dryer. The lint filter is located at the front of the dryer's tumbler, and is inserted vertically into the dryer. Gently stroke your hand over the filter to clear the lint, then reinsert the filter and close the door.
6

Turn the dryer off and allow at least 30 minutes for the dryer to cool, as excessive heat can cause a drying program malfunction.
7

Increase the ventilation of the room the dryer is located in, such as by opening a door or window. Excessive heat will cause the dryer to automatically turn off until it cools as a safety measure. Increasing the ventilation will help keep the dryer cool.
Clothing Not Fully Dry
8

Clean the moisture sensor. Open the dryer door to access the moisture sensor. The black-colored sensor consists of two bars, and is located at the front of the dryer's tumbler, to the left of the lint filter. The sensor should be cleaned with a clean cloth and white vinegar once per month.
9

Clean the lint filter. Twist the program selector knob on the control panel to the "Off" position, then open the dryer door. Pull out the lint filter. The lint filter is located at the front of the dryer's tumbler, and is inserted vertically into the dryer. Gently stroke your hand over the filter to clear the lint, then insert the filter back into the dryer and close the door.
10

Spin the laundry at a higher spin speed in the washing machine before placing the laundry into the dryer to reduce the moisture content.
11

Turn the dryer off and allow at least 30 minutes to pass for the dryer to cool, as excessive heat can cause a drying program malfunction.

Try to reset the thermal cutoff, but should be no reason why it should have tripped.
The actual operating procedure is
The air enters the body of the dryer through the large opening in front of the dryer
Then the air is sucked past the heating element and into the tumbler. (the tumbler is the large bin holding your clothes).
Then after the air has circulated around the clothes, it enters the door and is directed down through the lint screen. (this catches lint from the drying process... some clothes producte more lint (such as towels) than others (such as panties) because the weave is more coarse.
Then the air passes through a duct in the front of the dryer (after the lint filter) and into the fan.
The fan forces the air into the duct leading out the back of the dryer, at which point it exits your house.
It is extremely difficult to tell you the problem without being there to eliminate any one of several things that could be the problem. First, when you have the dryer turned on and have the heat setting set to cottons, is there ANY heat at all? If you feel the door, and there is SOME heat but there is not much heat on the clothes when you feel them, the intake opening in front of the dryer is probably in need of cleaning.

While you should always clean your lint filter after each use of your dryer, you should also periodically clean the intake at least once every six months. If you do not, the air intake is eventually restricted and the drying efficiency of the drye is affected. Consult your owner's manual for the exact location of the air intake.

IF THE INTAKE IS CLEAN and clear of obstruction, and there is still not enough heat to dry the clothes, but the door feels warm when dryer is operating. Then this would imply that the exhaust duct needs cleaned out. This is something that definitely needs done periodically to prevent fire. The exhaust duct collects additional lint that the lint filter misses. While this is a small amount of lint, over a period of time, this builds up on the inside of the exhaust duct and prevents the flow of the exhaust which reduces the heated air flow around the clothes in the tumbler. This results in the air not flowing and not becoming warm enough to dry the clothes efficiently.

IF THERE IS NO HEAT AT ALL: Then there is a likelihood that the heater itself needs replacement. This is a costly repair and you will be wise to invest in another dryer instead.

The working process of your clothes dryer is a relatively simple machine. It brings in air, heats the air, flows the air through the tumber where the clothes tumble loosely with the heated air circulating around them, then the air passes through the lint filter as it exits out your home. The lint filter is necessary because those tiny pieces of fabric (lint) can collect in your exhaust duct and catch fire. This is the major cause of dryer fires. This is why you should also periodically clean out your exhaust duct. Even though you have a lint filter, the lint filter does NOT catch all the lint and lint will eventually coat the interior walls of the exhaust duct.

Hi, If you are having problems with your gas dryer not heatingthe most common problem is that the ignitor goes bad. Even though it glowssometimes it is still not working properly. if you dryer is gas check out this gas no heat tip.... If you have an electric dryer, you can have many differentthings that can go wrong causing the dryer not to heat. check out this electric no heat tip...

heatman101
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Generic solution offered.

Usually when an electric dryer overheats it's because of a defective cycling thermostat or a clogged vent system. Clean any lint from the internal and external ductwork, and/or replace the cycling thermostat.

Proper air flow is required for the dryer to operate normally. Airflow is interrupted when the door or front panel is open and the heat will gain rapidly. Operate the dryer without the vent connected and if it works normally, then inspect/clean/replace your venting. Make sure you clean the lint filter after every load.

is it a condenser or vented tumble dryer

My guess is that the heater element has gone out. There could also be a lint clog in the exhaust vent...it takes air out through the filter...across the heater element....and back through the tumbler to heat the clothes. This is usually what causes heat elements to go out is the excess lint that gets on them and causes them to overheat and burn out!

I don't know if there is a cure for this. Bosch never answers my calls or my e-mails, but I have found that by blowing in the hose to disengage the lint collecting there and then sucking out the line will remove nearly all of the build up amd drying will resume.