If this is an ELECTRIC dryer, the following link will give you some advice on how to troubleshoot a no heat problem:http://www.fixya.com/support/r3576548-dryer_runs_but_does_not_heat
If this is a GAS dryer, the most common failure for heat related problems in a gas dryer is a weak or blown igniter on the burner assembly. The way the ignition system is supposed to work is like this:
1. Select the dryer cycle and press start.
2. The drum begins to spin and the igniter begins to glow.
3. Once the igniter reaches a certain current potential, the gas safety valve opens.
4. Gas is introduced into the manifold and you have ignition. NOTE
: It can take roughly 30 – 90 seconds
from the time you start the dryer to the time it takes for the gas to ignite.NOTE
: This is a designed safety feature of the appliance that prevents free flowing gas from accumulating in your home without ignition.
That’s why you typically don’t hear any gas flowing when you have an igniter problem.
You might think you have a gas problem when actually you have an ignition problem.TWO BASIC IGNITER TYPES
Carborundum (Cylindrical in shape) – needs to produce 2.5 to 3.0 amps for the gas safety valve to work.
Norton (Rectangular in shape) – needs to produce 3.2 to 3.7 amps for the gas safety valve to work.
NOTE: There is a UNIVERSAL FLAT BAR igniter on the market as well, that can be used as a substitute if the igniter type that came with your range is not available.
The igniter typically goes bad in one of two ways, the igniter either stops glowing completely, or becomes weak over time and doesn’t produce enough current to open the gas safety valve (in this case the igniter will still glow but the dryer still won’t light
Longer ignition times can be another symptom of an igniter possibly going bad.
You can purchase a replacement at any of the following websites:
The first three sites on the list also offer some excellent exploded view diagrams of the appliance.
If your replacement igniter comes with a connector plug that does not match your appliance, you will be instructed to cut the old plug off and splice the wires together using ceramic wire lugs included in the kit. Do not use standard wire lugs as they will melt.
If you have any questions, please post back with your complete model number and let me know. For future reference, always include a brand name and model number when posting questions. This makes it much easier to diagnose the problem. I hope this helps you.