Anybody here know how to fix gas dryers?

[fishy68]

I have a Maytag (you know the ones that never break, LOL) gas dryer that's about 6 yrs. old and recently it started taking 2+ hrs. to dry a normal load of clothes. I cleaned out the entire air duct thoroughly (wasn't really all that bad but while I was in there figured I'd try it). I ran it with the front removed so I could see the burner and I see it only runs for about 10 seconds and then shuts off for a couple minutes then runs 10 seconds, you get the drift. Right on top of the burner was the high limit thermal switch and I found if I bypassed it it will run forever but that's not safe so I can't do that. I figured it was just an overly sensitive thermal switch and bought a new one and tried it and it does the exact same thing. I tested what few parts it has, the temp thermostat, gas valve coils, temp control switch, overtemp fuse, flame sensor. All test good. The only part I can't test is the timer control but it gets power down to the main thermostat all the time so I think that means it's ok. I can't find an electrical diagram for it so I'm just winging it on that part but being I used to be a tv repairman I can usually figure electronics out. Especially something with only half a dozen parts. But this one has got me baffled.

Oh yeah I also found I can completely remove all wires from the main thermostat and it does the exact same thing so apparently it's running on the high limit switch only.

Anybody got any ideas?

Thanks, Tracy

 

[DUSTERDOWNS]

I Worked On Maytags For Awhile And It Sounds Like One Of The Solenoids On The Gas Valve Is Over Heating And Cools Off To Work Again For A While. Other Than That Only A Thermostat Would Shut Everything Down , You Said You Bypassed The Thermo And It Still Did The Same Thing. When It Shuts Down Try To Check The Solenoids For Continuity. Let Me Know What Happens. Steve

 

[JimmyV]

Man I Didnt Even Know That They Made Gase Dryers They Must Be Really Effeciant

 

[SpeedThrills]

This site has helped me: http://www.applianceaid.com/repair-help.html

 

[fishy68]

I Worked On Maytags For Awhile And It Sounds Like One Of The Solenoids On The Gas Valve Is Over Heating And Cools Off To Work Again For A While. Other Than That Only A Thermostat Would Shut Everything Down , You Said You Bypassed The Thermo And It Still Did The Same Thing. When It Shuts Down Try To Check The Solenoids For Continuity. Let Me Know What Happens. Steve

Hi Steve. I thought that might be it also because I've seen solenoids do that but just as soon as it shut down I tested both solenoids and they both still showed the correct ohms. I found another forum on the net similar to the one speedthrills posted the link to and it had what ohms the solenoids should be and they were real close. I also verified that as soon as it shuts down the electricity drops out at the solenoids.

Thanks alot, Tracy

 

[fishy68]

This site has helped me: http://www.applianceaid.com/repair-help.html

Thanks alot for the link. I'll check them out.

 

[Brian c]

is the flame sensor clean?

 

[fishy68]

is the flame sensor clean?

It looks clean as well as I can tell but since it's screwed into the side of the burner I can't see it really the flame side good. I'll take it off and check it closer.

How does the flame sensor actually work other than I know it senses the flame? What does it do when it senses the flame?

 

[memike]

What does it do when it senses the flame?
It will let the flame continue burning, If it don't get a heat reading from the sensor it will shut the gas valve off for safety so you don't fill your room with gas

 

[fishy68]

What does it do when it senses the flame?
It will let the flame continue burning, If it don't get a heat reading from the sensor it will shut the gas valve off for safety so you don't fill your room with gas

Hummm. That might be the problem then because it is definitely shutting the power off to the gas coils when it quits.

Do you know how to test it by any chance? Thanks Mike

Tracy

 

[toplscuda]

Remove it ans disconnect the wires. Use an ohm meter- resistance should be very low- near zero. Put it and use a 60 - 100 watt light bulb and check to see the resistance climb. If it doesn't,or only a little then replace it.

 

[fishy68]

Thanks everybody for all the suggestions but I finally figured out the problem today. It was a partially plugged vent hose. I cleaned out the dryer part and looked down into the vent hose (one of those corrugated plastic hoses) and it looked ok but it made 3 bends down under the floor before it went outside and right in between the bends it was clogged about half way shut. Apparently these newer dryers are pretty sensitive to it because the first thing I checked was airflow outside where the vent comes out and it seemed to be pushing plenty of air, or so I thought. Today I replaced the corrugated hose with regular vent pipe and it works great. I feel silly for letting something so simple fool me but I've learned a lesson.

Thanks again for all the help guys and have a great weekend. Tracy

 

[fishy68]

Remove it ans disconnect the wires. Use an ohm meter- resistance should be very low- near zero. Put it and use a 60 - 100 watt light bulb and check to see the resistance climb. If it doesn't,or only a little then replace it.

Hey Carl do you know about the new Mopar club just formed this year that meets out in Cottleville called Gateway Classic Mopar? You might recognize some of the names. I make it over when I can but it's a pretty good drive for me so I don't make it alot.

Here's a link to it.

http://www.gatewayclassicmopar.com/index.htm

 

[daredevil]

hey but we all learned something

 

[BillGrissom]

Wise you decided not to bypass the temperature limit switch since it was doing its job. In the days of screw-in fuses, many houses burned down after the copper penny fix.

Flame sensors used to be problematic. I tried understanding the circuit for one on a gas heater that stopped working. It appeared to sense flame ionization using a high-frequency oscillator to measure resistance. I couldn't understand or fix it so I paid $150 for a new one. For kicks, I looked over the new circuit and it appeared a totally different design (take 2?). All new appliance flame sensors I have seen sense the flame optically, using an IR detector. You can tell because they have a window near the flame. They seem much more reliable as long as you keep the window clear.

 

[fishy68]

Wise you decided not to bypass the temperature limit switch since it was doing its job. In the days of screw-in fuses, many houses burned down after the copper penny fix.

Flame sensors used to be problematic. I tried understanding the circuit for one on a gas heater that stopped working. It appeared to sense flame ionization using a high-frequency oscillator to measure resistance. I couldn't understand or fix it so I paid $150 for a new one. For kicks, I looked over the new circuit and it appeared a totally different design (take 2?). All new appliance flame sensors I have seen sense the flame optically, using an IR detector. You can tell because they have a window near the flame. They seem much more reliable as long as you keep the window clear.

I know what you mean about the old days. Things have changed with me alot since then. I never bypass a safety item except for just a short test session and then it has to be reasonably safe to try something. I value my house and life more than that.

This is my first repair experience with a dryer. I used to repair tv's and radio's in the old days of tubes and hybrids and early transistor stuff. Electronics sure have changed alot. I still tinker with electronics some with my ham radios but there is nothing in them like what's in a dryer so I didn't have any idea how a couple things worked. They seem to be pretty simple once you know how things work. The biggest problem I had was I couldn't find a schematic or wiring diagram so I had to wing it.

 

[Brian c]

It looks clean as well as I can tell but since it's screwed into the side of the burner I can't see it really the flame side good. I'll take it off and check it closer.

How does the flame sensor actually work other than I know it senses the flame? What does it do when it senses the flame?

it puts out a voltage. either 750 millivolt or a DC volt depending on if its a powerpile or thermo couple. the voltage runs throught the gas valve. if there is no voltage present it wont open the main valve and the burner wont light.
works kinda like a safety so your main valve doesn't open without a source to light the gas. It would suck to have gas pooring in and not being lite by a pilot.

 

[Brian c]

Thanks everybody for all the suggestions but I finally figured out the problem today. It was a partially plugged vent hose. I cleaned out the dryer part and looked down into the vent hose (one of those corrugated plastic hoses) and it looked ok but it made 3 bends down under the floor before it went outside and right in between the bends it was clogged about half way shut. Apparently these newer dryers are pretty sensitive to it because the first thing I checked was airflow outside where the vent comes out and it seemed to be pushing plenty of air, or so I thought. Today I replaced the corrugated hose with regular vent pipe and it works great. I feel silly for letting something so simple fool me but I've learned a lesson.

Thanks again for all the help guys and have a great weekend. Tracy

does it have a super sensitive air flow switch on it? probably something like 3 to 5 inches water colume. Thats good that you got it going :cheers:

 

[fishy68]

does it have a super sensitive air flow switch on it? probably something like 3 to 5 inches water colume. Thats good that you got it going :cheers:

I didn't see any air flow switch. I think what was happening was since it didn't have enough air flow the burner was flaming out more towards the sides of the burner heating the high limit switch up real fast. After I got the vent opened up good the flame looks smaller diameter and like it's drawing it towards the air intake more. Hope that makes sense.

 

[slantsixdan]

A really good appliance-repair Q&A forum is www.applianceguru.com . I have never failed to get quick, good, accurate answers there. They also have a lot of resources (service manuals, diagrams and such).

 

[64physhy]

I recently had the same problem on my Maytag. It turned out to be the solenoids, as others have already said. Since I was already in there, I also changed the flame sensor and 2 other temp sensors. The parts were really cheap. I got the parts on www.repairclinic.com

 

[WildCat]

Thanks everybody for all the suggestions but I finally figured out the problem today. It was a partially plugged vent hose. I cleaned out the dryer part and looked down into the vent hose (one of those corrugated plastic hoses) and it looked ok but it made 3 bends down under the floor before it went outside and right in between the bends it was clogged about half way shut. Apparently these newer dryers are pretty sensitive to it because the first thing I checked was airflow outside where the vent comes out and it seemed to be pushing plenty of air, or so I thought. Today I replaced the corrugated hose with regular vent pipe and it works great. I feel silly for letting something so simple fool me but I've learned a lesson.

Thanks again for all the help guys and have a great weekend. Tracy

you should feel silly,

I was going to suggest the vent pipe, you already said you checked it. I changed the vent pipe at our other house for the same reason. Solid pipe is much better than the flex pipe, but still needs cleaned out every so often.

I've been told one of the big problems is the use of fabric softener sheets in the dryer. they claim it will cause the lint to stick to the wall of the vent more than not using it. Sue switched to fabric softener in the washer.

Glad you got it fixed

 

[fishy68]

A really good appliance-repair Q&A forum is www.applianceguru.com . I have never failed to get quick, good, accurate answers there. They also have a lot of resources (service manuals, diagrams and such).

Thanks for the tip. I saved it in case I need something in the future.

 

[fishy68]

you should feel silly,

I was going to suggest the vent pipe, you already said you checked it. I changed the vent pipe at our other house for the same reason. Solid pipe is much better than the flex pipe, but still needs cleaned out every so often.

I've been told one of the big problems is the use of fabric softener sheets in the dryer. they claim it will cause the lint to stick to the wall of the vent more than not using it. Sue switched to fabric softener in the washer.

Glad you got it fixed

Let me have it Larry! LOL I should've looked closer.

Never heard that about fabric softener sheets but I sure can say the lint was stuck tight. That's another reason I changed out the hose. It was about 15' long so there was no good way to get to the inner part and clean it good. Another reason we use the fabric softener sheets is for the static cling relief. Does the fabric softener in the washer do anything to help that?

 

[Brian c]

I didn't see any air flow switch. I think what was happening was since it didn't have enough air flow the burner was flaming out more towards the sides of the burner heating the high limit switch up real fast. After I got the vent opened up good the flame looks smaller diameter and like it's drawing it towards the air intake more. Hope that makes sense.

sure does!!