WGD92HEFC Whirlpool dryer "check vent" light & moister sensing issues

[MxRacer965]

Model

WGD92H

Brand

Whirlpool

Age

1-5 years

Hi all, hoping to get some help (of course)!

I have a Whirlpool gas dryer model WGD92HEFC purchased from Sears in November of 2016 that recently started acting up. We generally leave the dryer in automatic mode, but we noticed the "check vent" light began illuminating constantly, and drying time has increased dramatically in some cases. The dryer outlet is very close to the outlet for the house and the only way I could make things work was to get a flexible 4" metal line that has a 90 elbow out of the dryer going up, makes a gentle curve down (180 over a couple feet), to a 90 at the floor that goes out of the house; I realize this is not ideal but it has worked for 2.5 years without issue. I checked for lint, etc and the line from the dryer out of the house is clean. I even ran the dryer without the line to the outside hooked up (venting into house) and the check vent still came on. Timed drying seems to be fine.

I tried googling the issue, and did a quick check of these forums and I can't find anything on this particular dryer that might help. I've read the sensor bars might be an issue, thermistor comes up as well, and I've seen references to diagnostic modes on the internet for other dryers...but nothing that references this unit.

Can someone here help get me pointed in the right direction?

EDIT: I did use the + and - buttons to enter what I assume is the diagnostics mode. I got "888" on the display and every light was on. I opened the door and got a beep plus display showed "999", then put my fingers over the moisture sensor bars and the unit began beeping and displayed "92". I assume this means the moisture sensor bars are good and things are working properly from that perspective based on what I have read about other Whirlpool dryers.

Thanks in advance!

Aaron

 

[MxRacer965]

Did some more testing last night; I disconnected the outside vent again and I put the dryer in diagnostics mode and ran it. Water everywhere inside since it is a steam dryer, but it ran without issue. I ran it without laundry in it to dry it out and everything was fine, no check vent light. I ran it again with laundry and no issue. Connected the vent again and ran a second load...check vent light illuminated. Put dryer in diagnostic mode again and ran it. No issue. Ran it again with nothing in it to dry it out and it ran without issue; check vent light stayed off.

The vent is entirely clear of lint (well, of course there are some fibers in there but it's as clean as a vent could be after 1 use), and the vent outside has no obstructions with the flaps able to freely open. The run from the wall to outside is all of 6" or so. I have this vent kit hooked up exactly as you see it pictured; out of the dyer 90 up, long 180 loop back down to 90 out of the house. Ran with this for 2.5 years without issue.

lowes.com/pd/Builder-s-Best-Indoor-Hook-Up-Dryer-Vent-Kit/4565890

Could it be the thermistor is marginal and when the dryer has nothing in (and/or no vent connected) it there is excessive air flow, allowing it to function but once laundry is loaded I assume the air flow decreases since now it has tumbling clothing inside, causing the thermistor to not function correctly and the dryer assumes the vent is clogged?

 

[Jake]

Hi Aaron,

I always advise my customers to try to clean the moisture sensor bars with rubbing alcohol and see if that makes a difference.

The sensor bars can get a build-up of fabric softener film from the dryer sheets, like Bounce, and cause this problem as well. Lots of members here have said the rubbing alcohol cleaning fixed their dryers.

Let us know it that fixes it.

Jake

 

[MxRacer965]

Thanks for the reply. I did clean the moisture sensor bars with alcohol first before starting down all the other troubleshooting steps, my apologies for not mentioning it.

Also while in diagnostics mode I placed my finger on the bars and the dryer did start beeping, indicating it was functioning.

Yesterday I also took the top cover off and found the service manual. I checked resistance of the thermistor and it came back fine (11.5 if I recall). I also had it go through the install tests and everything came back fine, including air flow. While the front was off I also cleaned all the duct work; there really wasn't much there. Just a little lint caked onto the motor blades; a very thin layer.

So everything is clean, thermistor checks out fine, moisture sensor bars seem to work, install test comes back fine...what could I be missing?

 

[Jake]

It doesn't seem your missing anything. The only other part left that would cause this is the control board malfunctioning on AUTO DRY, TIMED DRY is working great!

Control Board W10875487


Jake

 

[MxRacer965]

I noticed the other day when we last did a load it started out at 38 minutes, declined to 10 minutes, jumped to 53...I shut the dryer off and started it again and the drying time dropped to 10 minutes. I left before I could see what it did next but would this symptom further indicate the control board? I assume the only way to test the board is to replace it...

 

[Jake]

That's all it can be.

Now does it still jump like that if you pull the dryer out from the wall, then remove the exhaust hose, then dry the same load? Try it and see before you order the control board.

Open some windows to let the hot dryer air out when your running that same load.

Jake

 

[MxRacer965]

I haven’t had a chance to try any more diagnostics, we were on vacation for a week and a couple other things...

New symptom; even on timed dry the clothes come out damp even after a 50 minute run.

Does this change the culprit of our issues at all?

 

[Jake]

Ok,

Then you will need to pull the dryer out from the wall, then remove the exhaust hose, then dry a load and see if its completely dry in less than 60 minutes.

Open some windows to let the hot dryer air out when your running that same load.

Jake

 

[MxRacer965]

Thanks for the reply, ran out of town for Memorial Day!

Ran a load this morning with the vent disconnected, window open in the laundry room. Ran a load for 50 minutes and it was still damp to wet depending on the clothing. I opened the door a couple times and it was warm inside, but never anything close to "hot".

Still pointing towards control board or is this pointing to another issue?

 

[Jake]

Ok,

Stay with your dryer for awhile and I want you to listen to the gas flame coming on and going off. If when you first start the dryer you hear the gas flame coming on, does it stay on awhile? When the gas flame cycles OFF then ON again do you hear the gas flame fire back up and heat or not?

You will need a thermometer to take its temperature.

This Multimeter reads temperature, it comes with a probe you put in the dryer door. Just open the dryer door and insert the probe, then close the door and run the dryer with NO CLOTHES in it, and watch the meter. Don't put the probe to far in or it will be hitting the drum as it turns.

With the dryer on high heat, the temperature inside the dryer should be between 140*F to 180*F. Which would average 160*F.

Jake

 

[MxRacer965]

Thanks again for the continued replies!

I sat with it for about 15 minutes carefully listening for the flame coming on and off. Without knowing exactly what to listen for I had to be extra attentive...and apparently my 4 year old put a couple rocks in his pockets that started making a racket as I’m trying to listen!

At any rate I believe I heard it cycle on, heard a faint “whoosh” along with a low, quiet rumble of flame, followed by a click after some time and no noise. A short time later another faint “whoosh”...repeat. Hovering over the back of the dryer I also noticed the air getting alternating warmer and colder.

I have the multimeter on the way so I’ll be able to get further details once that arrives.

 

[Jake]

Ok sounds good, yes let is know the temps its giving when you get the new multimeter with the temperature probe in it.

Jake

 

[MxRacer965]

OK, I have some more results...

Turned on dryer. Reached 166 before it cycled off. Temp dropped below 90 before heating back up to 169 before dropping to just above 90...repeat...

I could hear what I assume is a solenoid at high temp click immediately followed by temps dropping. I heard it again around 115, then again 95, and again within a couple degrees of 90-95 followed immediately by heating back up to the high temp in the mid 160’s.

Would it be safe to assume it isn’t getting as hot as the auto mode expects, thus making the dryer believe there is a clog in the vent?

 

[Jake]

Ok, the problem is the gas coils.

Here's the gas coil kit for your model you can order here:
279834 Dryer Gas Valve Coil Kit


Jake

 

[MxRacer965]

Thanks for the reply again Jake!

I replaced the coils and tested again. Temp hit 180 then dropped to 95-100 before it started heating back up again. I heard the 3 clicks again as the temp was dropping and on the 3rd the temps increased again but didn’t go back to 180. It went to 170 or so and would drop to 100 or so before cycling back on. First click was generally just below 140 as an FYI. I thought maybe just because temps were dropping so fast due to no load in that maybe there was a safety timer or something to prevent it from cycling back on so quick.

Tossed in a load and gave it a try on the auto sensing mode (“Normal”). No check vent light, but the time dropped to 10 minutes remaining and jumped up to 50. Clothes were not dry at all. It’s currently at 48 minutes to go.

I’m going to try a timed dry next and see what happens, but clearly it is still not functioning correctly.

What else might it be?

 

[Jake]

If you still have this problem after you do what I recommend, then its possibly your thermistor.

Ohm test the thermistor at room temperature.

At room temperature or 70*F the thermistor should show between 11.5K and 11.9K ohms (11,500 -11,900 ohms).

Normal thermistor resistance values:
60 degrees F. - 15.3K ohms.
70 degrees F. - 11.9K ohms.
80 degrees F. - 9.2K ohms.

Here's the thermistor for your model:
Thermistor WP8577274


This video shows how to access it: Duet/HE3 Electric Dryer Thermistor Video

Make sure you unplug your dryer first and keep it unplugged when ohm testing.

Jake

 

[MxRacer965]

Last I checked the thermistor it was 11.5 ohms around 70 but I also took that reading at the connector to the control board and not at the thermistor itself.

I did not replace the control board ever, BTW.

 

[MxRacer965]

Somehow I found where to edit my post yesterday and I can't figure it out now, lol...

Anyway, I was just going to edit and ask if I should replace the control board since I hadn't done that yet...I posted my new symptoms of timed drying not working several comments ago in hopes that I wouldn't need to spend for a new board. If that is the proper course of action I'll get that ordered next, otherwise if you believe the thermistor is the next course of action I'll get that on order and replace it next.

Thanks again for all the help!

 

[MxRacer965]

Dug into it again for a bit. I found it is only heating to 110-120 before turning off now, and temps drop to the mid 80's before it cycles back on.

I checked the resistance of both thermistors at the harness that connects to the CCU. They checked out fine. I forgot to write down the values before I tried running the dryer and now the readings are a little "off" since they were hot. The output thermistor was reading 11.3 and increasing last I checked it, and the input thermistor was at 52.3 and increasing last I checked it.

For the heck of it I checked the OLD coils. Pin 1 & 2 read at 1408, manual says 1400 +- 70 so that was in spec. Pin 1 & 3 read 581, manual says 570 +- 28.5 so that was in spec as well. Pin 4 & 5 read at 1302, manual says 1300 +- 65 so that was in spec as well. So the old coils checked out good in the end.

I have not checked the thermal fuse, I assume if it were toast then it wouldn't work AT ALL.

I have NOT checked the flame sensor, high limit thermostat, or the thermal cut off. I have NOT replaced the CCU yet either.

I pried the inspection cover off and observed the operation as well. The igniter came on, followed by the gas igniting. Flame looked healthy to me but then again it's the only time I've ever had to check out a dryer. Once the dryer reached 110-120 I heard a "click", the flame went out, and the temps started dropping. After a drop of about 15 degrees I heard another "click", followed by the temps dropping to around 90 when I heard another "click", followed by the igniter coming on, another "click" and gas igniting.

So...given all of this am I at the point I need to bit the bullet and spend the hundreds of $ for a new CCU?