FIXED EW30EW65GS8 Stops heating after preheating

Ddza

Premium Member
Joined
Jan 7, 2019
Messages
7
Location
USA
Model Number
EW30EW65GS8
Brand
Electrolux
Age
6-10 years
My issue is a little different but I did use the info in the other EW30EW65GS8 threads to troubleshoot as much as I can. This will be long as I have been working on this all day testing everything I can find info on.

The oven heats normally during preheating but temp continuously drops after desired temp is reached despite showing both heating elements turning on and off to maintain temp. Pressing cancel and restarting preheating displays the correct temperature on the front panel (as measured by a multimeter temp probe that tracks accurately to a different oven) and heats the oven back to the desired temp and the cycle repeats (cools after preheating completes). On some tests I let it drop 60 degrees to see if would ever reheat. Canceling and restarting preheating always works.

The K3/K5/K7 upper oven relays open and close as expected per the front panel indicator (tested by ohm meter).

Voltage measurements directly on the contacts for the upper (broiler) and lower (bake) heating elements confirm what I measured on the relay board: ~244 VAC to the appropriate heating element (per front panel indicator) both during preheat and the bake/broil cycle as the oven tries to maintain heat. But temp continuously drops after preheating is complete (if not using rapid preheat which lies about preheating being completed).

I’ve checked the temperature sensor and it measures 1097 ohms, which is within spec. I didn't expect it to be the issue as the preheating cycle and cancel/restart preheating work and report correct temp per digital temp probe.

***I don't understand how the temperature can continue to drop with 244VAC applied to the heating elements given that they work fine repeatedly/everytime during preheat cycle. ***

I've checked this with two relay boards (swapped the old relay board back in) and the symptoms and measurements for the upper oven are unchanged.

I've pulled the back covers and measured directly off the downstream contacts to make sure there isn't some thermal cutoff that trips and resets.

What am I missing?



Note: All of this refers to the top oven. The bottom oven has been INOP for sometime (second failure after complete electronics/power supply component swap out under extended warranty). My wife thinks both failures followed a clean cycle (memory is a little hazy). The oven and stovetop are the only Electrolux units remaining, Gave up and replaced the dishwasher and microwave long ago. Good mechanical build quality; horrible electronics reliability.

Since I had no choice but pull the unit out and test when upper oven failed yesterday, I've since confirmed output voltages for lower oven's upper (broil) and lower (bake) heating elements are NOT right despite DC relay (K4/K6/K8) input voltages being correct (~9VDC when on, 0 VDC when off) and controller board input signals for J5 Conv/Bake/Broil/DLB) turning on/off appropriately (~3.3VDC, so I assume it's an input signal only). No output voltage to broil element and only 122VAC to bake element. Testing the P8/P10/P12 contacts -- all three are closed/shorted to relay common/L1 input (P6) when the K4 relay is energized (~9VDC input). Need to test lower oven more but it's been a long day.

I stopped testing for the night to post this message, but I'm confident the upper and lower oven issues are unrelated. I just wanted to present as complete information as I can.

I will reinstall the 2nd relay board and recheck all lower oven relay operations and output voltages to see if they're consistent between boards. All DC relay inputs from controller board inputs to relay measure as correct including DLB, so I'm pretty confident lower oven issue is in relay board.

To reiterate, all DC relay inputs for upper oven relays (K3/K5/K7) operate correctly and the heating element voltages (as measured directly on the connections) check out. Note: the convection fan checks as well (normally on @ ~81VAC but I assume that's speed control) and the fan does spin as expected per visual inspection.

The priority right now is to get the upper oven working for my wife. Any help would be greatly appreciated.

Thank you.
 

Ddza

Premium Member
Joined
Jan 7, 2019
Messages
7
Location
USA
Day 2 update

Upper oven:

Swapped back to newer relay board. Same symptoms.

Tested thermal fuse. Not tripped after preheat. Did not expect this to be an issue as voltage test points are after fuse, but tested anyway.

Broiler test points are blade connectors on back panel. Bake test points are fuse output blade connector and P9 connector on relay board. Convection test points are blade connectors on fan on back panel.

Still really confused how heating elements work perfectly during preheating but don’t heat with 240 volts applied after preheat.

On a side note, cooling fan continuously runs during bake operation. Cannot remember if this is normal, but seems strange to be cooling oven during baking.

Lower oven:

Ohmed out heating elements. Both are within spec per what I’ve read.

Lower broiler: 14.3 ohms
Lower bake: 23.9 ohms

Broiler element is not shorted on either terminal (bare element to each terminal). Bake element is too hard to get access to (I can’t any info on replacement procedure for hidden element. Looks to be a bear.)
 

Ddza

Premium Member
Joined
Jan 7, 2019
Messages
7
Location
USA
Update:

Think I may have it figured out. It’s the bake hidden element on the upper oven. Ohms out as OPEN. No current flow. Broil is 16 Amps when active. Anyone have a guide for replacing it on this model? I’ve found nothing so far and it looks like NO FUN.

Amazingly it was preheating just off the broiler because of the higher duty cycle during preheating. Heating during cooking is on and off so fast it can’t maintain temp at anything above 200 degrees. 200 degrees bake cycle works just slow to reheat.

Hope this helps someone else in troubleshooting.
 

Ddza

Premium Member
Joined
Jan 7, 2019
Messages
7
Location
USA
Instructions on page 10 of service datasheet located inside unit. Basically pull off door, pull off trim plate, move door lock out of way, drop heatr tray and disconnect wiring harness and pull out. My element was broken as expected.
 

Jake

Appliance Tech - Admin
Staff member
Joined
Aug 24, 2004
Messages
102,082
Location
McMullen Valley, Arizona

Ddza

Premium Member
Joined
Jan 7, 2019
Messages
7
Location
USA
EW30EW65GS8 Round2: Lower Oven

Parts arrived today and the lower element (bake) in the upper oven is functional again. Also purchased a relay board but the lower oven symptoms are unchanged.

Symptoms: no heat from either element but conv fan runs.

VAC measurement for broiler (directly on connectors on back plate): ~0VAC (element on or off as indicated on front panel)
bake element (output of thermal fuse connector and P9): ~122VAC (element on or off with oven on, 0VAC when oven off so DLB is working. Digital multimeter dances when relay switches before settling back ~122VAC.)
conv fan (directly on connectors): ~93VAC when on

I can hear the relays switching on and off. Isolated functions to ensure I heard the right relays. I haven't tested this board, but the other two I did measure the DC relay inputs, relay open/close/state and all appeared good.

122VAC on bake indicates DLB disengaged and only 1 leg active if I'm grokking this correctly.

0V differential between P5 & P6 so L1 input for lower oven appears OK.

Any ideas what is going on or how to further troubleshoot?

Thank you
 

Jake

Appliance Tech - Admin
Staff member
Joined
Aug 24, 2004
Messages
102,082
Location
McMullen Valley, Arizona
Here's the tech. data sheet for your model: https://drive.google.com/open?id=1ft9d_HPQu_CVo1c2jeHS5odVZlg6f9tP

On Page 7 LOWER OVEN ON DOUBLE WALL OVEN CIRCUIT ANALYSIS MATRIX

P10 is the bake relay for the lower oven. P2 is L2 out.

So Measure between P10 and P2 for the lower oven when set to bake (240 VAC). If the voltage checks good check the high limit thermostat.

There's a high limit thermal thermostat switch mounted on the back of each oven. It has a small red reset button in the center that will pop out if it gets too hot. See if you can push it in to reset it.

Rick made this diagram for another person with the same problem. His was a Kenmore but it is the same relay board as yours.
790.42003 kenmore pro dbl oven relay.jpg

316443919 Board


318004902 High Limit Thermal Switch


Let us know what you find.

Jake
 

Ddza

Premium Member
Joined
Jan 7, 2019
Messages
7
Location
USA
Jake,

Thanks for the reply and the information.

I had originally checked the red buttons assuming they were some kind of breakers, but never went back and measured resistance. The lower oven high thermal switch is not tripped (button is not extended) but it is an open circuit. the upper oven switch is shorted as expected.

Is there a reset function or this just an non-operational switch?
 

Ddza

Premium Member
Joined
Jan 7, 2019
Messages
7
Location
USA
Temporarily bypassing the thermal switch restores all operations. Part ordered.

Thank you



I feel like a complete dumb**s. Testing continuity on any fusable link is troubleshooting 101 and should have been done first. I literally forgot they were there. Live and learn (then forget and relearn). Thanks again.
 

Jake

Appliance Tech - Admin
Staff member
Joined
Aug 24, 2004
Messages
102,082
Location
McMullen Valley, Arizona
Excellent, don't feel bad I've done it before too a long time ago and learned after that to always ohm test the thermal thermostat switch first, even if the red button resets or not.:)

Glad that's all it was, besides the element.:)

Thanks for the update!

Jake
 
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