My Defy Tumble Dryer model DTD256 is not heating its blowing cold air. My on off switch broke so i opened up to fix it and when i closed up it wasnt heating but it comes on and turns etc.

have the element checked as it may be burnt out
check the element fuse ( if there is one )

If your dryer is an electric dryer, it is sounding like you have either a bad heating element or one of the two limit switches are open. The limit switch is an "overtemp" device to shut down the element if it gets too hot from air restriction. Lint build up in the blower and ducting is a major cause of restricted airflow across the heating element. Excessive tripping of the limit will result in an "open" limit switch and continual failure to generate heat. There should be one limit switch built into the heating package and the high limit will be located on the drum usually near the top, though there are some near the bottom of the drum as well. Any attempt to find and replace must be done with the power off as you are dealing with 240 volts.

If your dryer is gas fired, you've had a misfire probably due to a defective hot surface igniter or bad control module. Unless you are fairly capable of learning as you go, and have the basic tools for troubleshooting you probably need to call a sevice technician.

Unplug the unit. Using a ohm meter you need to check of the heating element is good or not. Reading across it you should see very low resistance. If you don't it may be "open" or a thermal interrupt has stuck open preventing current flowing through it. Check your high and low limit switches (sensors) for closed circuit (low resistance). If one reads high or open that one needs to be replaced.

It's either the fuse, heating element, thermal cut-off or thermostat

that isn't a model number,open the door to the dryer,look around the opening where you put the clothes in and send the full model number,

http://www.partselect.com/dryer+dryer-wont-heat+repair.htm

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If you are having problems with your gas dryer not heating the most common problem is that the ignitor goes bad. Even though it glows sometimes 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 different things that can go wrong causing the dryer not to heat.

check out this electric no heat tip...


heatman101

sounds like a heating element. not to hard. remove the back and its is right there.

Most likely heating element or thermal cut-off is bad, or both.

It's call a bad thermal cut-out. You should have a thermal cut-out and a high limit thermostat located adjacent to the heating element (usually mounted right on the heating element housing). They both should read a short or fairly low resistance in the case of the thermostat. If the thermal cut-out is blown it is not a resettable device and must be replaced. The tco is usually sold along with the high limit thermostat. It is HIGHLY recommended that you replace BOTH at the same time. DO NOT attempt to bypass any of these devices either. They are there as safety devices to prevent overheating. You could end up with a fire if you do. Now...with all that said, the tco will blow for a reason. Not cleaning the lint trap will contribute to it, but the big item is the ducting. If the vent ducting is clogged you will experience longer dry times and eventually the tco will trip again. Take the time to THOROUGHLY clean and/or replace your vent ducting from the wall all the way to the vent opening outside. In addition, while you have the dryer open THOROUGHLY clean the inside as well. This includes the air baffle where the blower fan is located. Rule of thumb: if you have lint INSIDE the dryer, it's clogged somewhere. Good luck and I hope this helps you.