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Forum Index => Dryer Repair => Topic started by: kid_sketch on January 15, 2010, 09:07:44 PM

Title: Kenmore 70 Series Electric dryer wont heat up
Post by: kid_sketch on January 15, 2010, 09:07:44 PM
I have the same dry (http://appliancejunk.com/forums/index.php?topic=5509.0) and is not heating up. the coil has a yellow powder. looks like corrosion on a battery. was wondering if this may be an indicator thee coil is bad. I have seen many posts about this dryer/problem don't have a tester with me at the moment to check fuses and such.

Model 110.64722400
Title: Kenmore 70 Series Electric dryer wont heat up
Post by: schaffersapplian on January 16, 2010, 04:02:41 AM
The "heat" circuit on a dryer is more then meets the eye.  The only way to test the machine is to have a multi-meter.... there are many components that make the machine heat... your ultimate goal is to have have 240 volts to the heating element.  The motor, timer, thermal fuse, heating element, thermal cut-off, and the hi limit thermostat could all be suspect without the right tool for the job.... There also could be an issue with the breaker and or wiring of the house, or dryer.... Any one of our serve tech's will be glad to walk you threw this repair, but to diagnoses the problem properly u must get a meter. 
Title: Kenmore 70 Series Electric dryer wont heat up
Post by: JWWebster on January 16, 2010, 09:31:01 AM
I have seen powder on element and blowers, I thought it might be from fabric softener
Title: Kenmore 70 Series Electric dryer wont heat up
Post by: kid_sketch on January 16, 2010, 12:16:14 PM
Thank you JW for at least trying to answer the question I asked unlike your counter part. The powder is awfully acidic I don't be believe its from fabric softener it is only on the coil it self not on any surrounding parts. So I'm going to assume that the powder is not an indication that the coil is bad if that is what you think it is from, for now at least. I just never seen such a strange build up like that before on any of my other appliances. As far as the proper tools go, I have them but thank you for rambling about things I didn't ask about  schaff  i always enjoy wasting my time.
Title: Re: Kenmore 70 Series Electric dryer wont heat up
Post by: AJ on January 16, 2010, 12:33:57 PM
Hi kid_sketch,

Please be sure to read, Posting Basics - Starting a New Topic (http://appliancejunk.com/forums/index.php?topic=443.0)

Note towards the bottom were it says,

Quote
# Please do not ask your own question in a topic.
In other words, please don't hijack the topic and make it yours.
Start your own topic and reference the other topic related to your issue.

I have split your post into a new topic and reference the other topic for you.

Quote
I have them but thank you for rambling about things I didn't ask about  schaff  i always enjoy wasting my time.

He is just trying to be helpful. All our technicians are volunteers, please try to show them a little respect.

Thanks for posting your questions.
Title: Re: Kenmore 70 Series Electric dryer wont heat up
Post by: kid_sketch on January 19, 2010, 04:17:03 PM
My apologizes to Schaff I was quiet rude, but the question I asked would have been better answered with a yes or no, and it seemed as thought the original poster had his problem resolved. I understand that electrical systems are imposable to diagnose with out equipment to test. That is why I posted not have the equipment with me at the time the post was made. Once again I am sorry I know you guys are doing this to help others with lesser experiance in appliance repair and that im sure it is not always easy to understand exactly what some one is trying to communicate via the board.
Title: Re: Kenmore 70 Series Electric dryer wont heat up
Post by: niobrara on January 20, 2010, 06:02:35 PM
If you don't have a meter handy , pull the element out and look at it to see if the wires are connected.Be carefull with it as the break may be on the holders.
Title: Re: Kenmore 70 Series Electric dryer wont heat up
Post by: kid_sketch on January 20, 2010, 08:48:42 PM
I now have my tester back in my possession. i checked the power coming in to the machine looks good 120/120. i then tested the high limit and cutoff each with a wire removed and it had a reading of 120v to one wire on each, with the unit running. The cutoff seemed to have power even while not running. switched my tester to check ohms. leads together reading 0. with machine running i showed a reading of 1.8 to 1.95 or so in both the cutoff and high limit. suggestions on where to go from here?
Title: Re: Kenmore 70 Series Electric dryer wont heat up
Post by: JWWebster on January 20, 2010, 09:48:51 PM
Disconnect power and do some continuity readings. Check the element continuity, what do you get?
Title: Re: Kenmore 70 Series Electric dryer wont heat up
Post by: kid_sketch on January 21, 2010, 11:41:43 AM
I received a reading of .010
Title: Re: Kenmore 70 Series Electric dryer wont heat up
Post by: JWWebster on January 21, 2010, 11:50:46 AM
did you remove the wires?
Title: Re: Kenmore 70 Series Electric dryer wont heat up
Post by: kid_sketch on January 21, 2010, 11:52:09 AM
so this means im lacking continuity in the element and is most likely the problem correct?
Title: Re: Kenmore 70 Series Electric dryer wont heat up
Post by: kid_sketch on January 21, 2010, 11:54:58 AM
I checked both with and without wires connected. same reading .010
Title: Re: Kenmore 70 Series Electric dryer wont heat up
Post by: JWWebster on January 21, 2010, 01:47:39 PM
Remove and inspect the element for breaks I think it is bad.
Title: Re: Kenmore 70 Series Electric dryer wont heat up
Post by: jumptrout51 on January 21, 2010, 01:59:14 PM
You said you read 120volts on each leg at the terminal block. Do you read 240 volts across the 2 hot legs there?
With your meter set for volts and the dryer running in a heat mode do you have 240 volts at the 2 terminals on the heating element.
If so the element is bad.
If not start back tracking to all thermostats and relays checking for continuity of the part with the dryer unplugged and the wires removed from the component.
Those parts would be the hi-limit thermostat the thermal cutoff and the operating thermostat.
You can check the motor relay centrifugal switch to make sure it is closing to send one leg of power to the element.
Title: Re: Kenmore 70 Series Electric dryer wont heat up
Post by: kid_sketch on January 21, 2010, 03:20:37 PM
inspected element but didnt see any sings of breaks/cracks.
I do have 240 across the 2 hot legs comming in to the machine. i also recived 240 cross the legs of the cutoff(while running) but not to the element or high limit.
element continuity still .010
high limit & cutoff both with no reading change (shows 1. on digital meter)
thermal fuse shows .000
operating therm(4 pole) one set shows .000 other set read no change (shows 1. on digital meter).
Title: Re: Kenmore 70 Series Electric dryer wont heat up
Post by: kid_sketch on January 21, 2010, 08:03:08 PM
do you still think it may be the element?
Title: Re: Kenmore 70 Series Electric dryer wont heat up
Post by: AJ on January 21, 2010, 08:11:09 PM
Quote
i also recived 240 cross the legs of the cutoff(while running) but not to the element

If you put one lead on each side of that cutoff and read 240 Volts then that cutoff is open (bad) like a fuse.

If the cutoff was closed (good) then you would be putting both leads of the meter on the same hot line and not get any voltage reading.


Title: Re: Kenmore 70 Series Electric dryer wont heat up
Post by: kid_sketch on January 21, 2010, 08:43:22 PM
ok sorry im not sure what i did earlier but i jus retested the cuttoff.. when i but the two lead to both poles i didnt recieve 240. it didnt read anything. i showed 120 with one lead on hot line and one to ground.
Title: Re: Kenmore 70 Series Electric dryer wont heat up
Post by: JWWebster on January 21, 2010, 09:14:30 PM
then that means you need to replace it or the element won't fire off
Title: Re: Kenmore 70 Series Electric dryer wont heat up
Post by: JWWebster on January 21, 2010, 09:16:18 PM
Note: they send both the limits for a reason. The lower one nearest the element terminals is set fer 250F the upper smaller one is set fer 300F. If the upper one fails then that means the lower one did not do it's job either.
Title: Re: Kenmore 70 Series Electric dryer wont heat up
Post by: AJ on January 21, 2010, 09:30:53 PM
Here are the steps I would take to check your dryer.

I know you have done some of these already.

1. Check for 240 volts were the dryer cord attaches to the dryer.

Some times people will check power at the outlet and it's ok, but later find out it was a burnt up connection were the power cord attaches to the dryer that was giving them the problem.

2. Check to see if you have 240 Volts to the heating element.

Put one probe on each terminal of the element to check. If you have power to the heating element, but it does not heat then replace the element.

3. If you don't have power to the heating element then I would check the thermo cut-off that is mounted up high on the left side of the heater canister.

Check the thermo cut-off with a ohm meter. If it ohms out it's good. If you get no ohm reading just as if you did not have the probes on the thermo cut-off then replace the thermo cut-off.

Make sure you have the power off and at least one wire pulled of the thermo cut-off when checking it with a ohm meter.

4. If the upper thermo cut-off is fine I would then check the second thermo cut-off that is located near the bottom of the heater on the left side.

If all the above items seem to check out ok then I would move on to checking the timer and the switch on the motor.

Sometimes you can check the timer just by looking at the back of it. There maybe a burnt wire or spade on the back of the timer.

The switch on the motor is a centrifugal switch and it kills the power to the heating element when the motor is not running and kicks in power to the heating element when the motor is running.

This way the heater will not operate if the motor blower is not running. It's a safety thing. If the contact are burnt up on that motor switch it maybe the reason why you have no power to the heating element.



Title: Re: Kenmore 70 Series Electric dryer wont heat up
Post by: AJ on January 21, 2010, 09:36:42 PM
ok sorry im not sure what i did earlier but i jus retested the cuttoff.. when i but the two lead to both poles i didnt recieve 240. it didnt read anything. i showed 120 with one lead on hot line and one to ground.

Testing it that way it sounds like it's good. The most common way to test them is with a ohm meter for continuity.