Author Topic: LG gas dryer wont heat  (Read 16123 times)

Offline berniet

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LG gas dryer wont heat
« on: December 26, 2007, 11:33:35 AM »
Hi I am formerly Thomas68  I had troubles logging in.

My LG DLG3788W Gas Dryer is tumbling...ignitor glowing...but no flame is being produced....

i have the front cover off and top off... i have the contol board hooked up... I have bypassed the door switch to get the dryer to work...It is in the condition above for live testing...

Question 1
Do I need the door on to cause air flow over the ignitor Assembly to have the gas air mixture to flow? ???
2
does the Hi limit themistat limit the voltage going to the coils on the ignitor?

When I am doing a test in its present state Should I probe the coil connector attached to the coil or not attached to the coil? ???

3 Should I measure accross the 2 wire connector going wire to wire...or should I probe wire to chasis ground?? when testing for voltage at the coil..

Any help is wonderful

Offline RegUS_PatOff

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Re: LG gas dryer wont heat
« Reply #1 on: December 26, 2007, 01:08:47 PM »
did you do the "GAS Valve test" on page 27 of the service manual ?

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Offline rickgburton

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Re: LG gas dryer wont heat
« Reply #2 on: December 27, 2007, 02:46:40 AM »
OK, the igniter (Glow coil) comes on . Does it turn off? Can you hear a "click" sound coming from the gas valve when you first turn it on? Remove a wire from each component before you test it. You're only looking for continuity for now. You want a reading of 0.0 on each component.
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Offline accapp

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Re: LG gas dryer wont heat
« Reply #3 on: December 28, 2007, 02:08:54 AM »
The door need not be installed for the gas valve to operate, it will shut off once the burner tube high-limit gets too hot. The LG operates differently from any other gas dryer I have encountered, the high limit will shut off power to the ignitor/flame sensor. There does not apear top be any direct connection between the ignitor/flame sensor and the gas valve coils which receive ~90 vdc from the control board to operate them. To test the control board, pull the two harness plugs off the gas valve and see if they are getting the correct dc voltage whn they should. The most important test is still gas valve coil continuity, it should be ~1180 ohms. Most LG gas dryers I work on need a new gas valve.
"When you have eliminated all which is impossible, then whatever remains, however improbable, must be the truth." Sir Arthur Conan Doyle.

Offline berniet

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Re: LG gas dryer wont heat
« Reply #4 on: December 28, 2007, 09:19:58 AM »
It does come on an Glow for a little bit and then it shuts off.
Is the Thermistat high limit the one located in the plastic squirrel cage assembly,  The Thermister is right next to it???I only get about 30-40 volts to the valve assembly.

I am using the diagnostic on that page and really do not know where the Thermistat Hi limit is for step 2

Offline berniet

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Re: LG gas dryer wont heat
« Reply #5 on: December 28, 2007, 09:28:55 AM »
Dlg diag for valves

Offline RegUS_PatOff

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Re: LG gas dryer wont heat
« Reply #6 on: December 28, 2007, 12:09:21 PM »
It's one of these (2) wired in series on the duct

one of them MAY have MANUAL reset button

the other one is automatic reset

as shown on page 16 of the service manual

M220  6931EL3004B 

M230  6931EL3003C

« Last Edit: December 28, 2007, 12:24:40 PM by RegUS_PatOff »
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Offline berniet

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Re: LG gas dryer wont heat
« Reply #7 on: December 28, 2007, 02:48:53 PM »
Here is the Schematic of the dryer.    where should I begin

Offline accapp

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Re: LG gas dryer wont heat
« Reply #8 on: December 28, 2007, 03:41:51 PM »
Do you have the meter set for DC volts when you are live testing? Are you measuring between both leads to each coil and not to ground? What is the resistance of each coil?
"When you have eliminated all which is impossible, then whatever remains, however improbable, must be the truth." Sir Arthur Conan Doyle.

Offline berniet

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Re: LG gas dryer wont heat
« Reply #9 on: December 28, 2007, 08:54:43 PM »
Acapp
I am unplugging the coil and testing in the plug....I am hoping this is correct..I get around 32 volts on the test....Per the manual that I am taking these measurments in AC...

the coils are ohming out to about 1700


 

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