Gas Dryer Trouble Shooting – No heat or flame shuts down

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No Heat

The first thing to do is to gain access so you can see the burner area and watch it during start up. I will suggest that you wear safety glasses as a precaution.

The first thing that happens is an igniter usually glows. It takes a little while for this to happen, There could also be a spark igniter.

The next thing that happens is the pilot gas valve is opened and the pilot gets lit. At this point the pilot gas valve could be faulty or the igniter could be faulty.

Once the pilot is lit, the flame has to be proven. Usually this is done by a capillary tube that's heated. Once this tube is heated the main gas valve opens and the main burner ignites. This capillary thermocouple could be oxidized or the main burner valve could be faulty if the main burner fails to ignite. There also could be flame rectification to prove a flame.

Some of the main burner flame is re-directed to the capillarity tube by what I might call the “cobra head”. If the burner runs for short period and shuts off, make sure that head does not flex. This usually is an intermittent condition that will eventually fail.

Flame shuts down

Aside from the condition above, there should be a sensor located in the ductwork that looks at exhaust temperature. If this is excessive, the dryer will shut down.

The main cause is lint build-up. The exhaust tube and inside the dryer as far as you can reach from the exhaust opening should be cleaned annually.

A secondary cause relates to the blower assembly. The bearings may need to be cleaned or the belt is slipping. This requires more disassembly.

Notes:

I've maintained my own gas dryer since 1968. Very little maintenance is required:
1. Igniter replacement, probably about 4x
2. Burner head replacement 1x
3. Exterior paint 2x
4. Interior paint 1x
5. Clean lint annually
6. Service blower bearing 1x
7. Replace drum belt 1x
8. Replace blower belt 1x
There are usually diagrams on www.searspartsdirect.com . There are plenty of aftermarket parts available so don't panic if sears doesn't have the part or they say it's obsolete.

My Maytag Gas Dryer ignites and the burner comes ON and later goes OFF quickly in 5 -10 min
Later the fame doesn't com ON

Ignitor glows and it clicks OFF

MDG7400AWW Difficult to start dryer while pulling out on the start switch/timer knob?
Why?

Picture of ignitionburner pilot

To remove lint deposits it is necessary to take all parts that handle the airflow apart to get to all of the dirt. Any restriction will cause a fire or the drier to fail. Don't try to take short-cuts on this step or you will have to take all apart again. It's not worth the hassle. Wash out the parts to remove all dirt or it will build right back up where you left deposits. Cleaning the drier is the most important thing you will do for the drier as dirt is usually the cause of all your problems just like with air conditioners. DrTom4444

Quote:

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Originally Posted by mmpatel

My Maytag Gas Dryer ignites and the burner comes ON and later goes OFF quickly in 5 -10 min
Later the fame doesn't com ON

Ignitor glows and it clicks OFF

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Hot Surface Ignition "HSI" use the phenomenon of "Flame rectification" tp "prove" a pilot flame exists, yhus is safe to continue on to main burner, this may be a direct lifghtoff type(usually) burner assembly, with no provision for a "pilot" flame"
as describd by the earlier poster, the '3 wire switch" type he describes using a capillary tube sensor isn't relevant with "intermittant pilots" or "standing pilot" type setups. Most units will have a ignitor which you know works as described, what is failing is the proving the flame exists, thus shutting down for safety.
99% of the time the ignition modules bad, there can be a issue with the burner assemblys ground, or a ground wire to the ignitor module, this is how the rectified signal is received by the module . The spark is a AC signal rectified to a DC signal if it passes through a flame, its only millivolts/milliamps so can be disrupted easily. Corrosion or patina is enough to do it, but not generally the issue.
Simply wire a 105 degree celsius wire from the burner to the sense or ground terminal on the ignition module to see if it stays running, odds are it won't and a modules needed, this is the case 99% of the time, do not touch or bump the ignitor that are very fragile, but if it glows and lights up the flame its OK.

Here are some manuals to help: https://dl.dropbox.com/u/8010163/Whirlpool%20Dryers.zip
There is a gas troubleshooting part that shows what you should read on your meter which is the only way to troubleshoot it. I clean the flame rod with fine sandpaper and sand the mount so it makes good contact with ground. A dirty dryer will also burn out safeties, so you need to check them with a meter as it can be something very simple like a safety which is round with an oval mount and two plugs for the wires. Just unplug one wire and check with an ohm meter which should read zero or close to it. Here is a manual on how to use a meter: https://dl.dropbox.com/u/8010163/Whi...e%20Manual.pdf
When you clean a dryer you have to totally disassemble it. Remove the drum and then take out things like the lint filter housing and clean it and wash it out. Any other ducts must also be removed and cleaned. Mark the wires you remove. Just cleaning it the way you described above absolutely will not work. That could be the main cause of your problems.