[tlgarrison]

I have a Roper RES7646KQ2 Dryer. Last year I had a bad heating element and replaced it. It has worked fine until yesterday.

The unit tumbles the clothes but no heat. So I checked the continuitiy of the Heating Element and it was fine. I tested the thermal fuse and it was fine, I tested the thermostat under the thermal fuse (low end thermostat) and its continuity was fine. I then tested the Hight end thermostat (on the heating element assembly) It had continuity, I then checke the thermal cut off located above the heating element and it had continuity.

So I then checked my circuit breakers (both are locked together and fine). I checked the power at the back of the unit at the terminals center terminal to left (120 v) then center terminal to right (120v) then I tested the outer two terminals and it was at 240 V.

What could be keeping the unit from heating? The timer is advancing during the cycle.

I am not sure what else to test.

Ideas?

 

[hardwareman]

sounds like you have a pretty good knowledge of what to check and how to check it so I feel fairly confident you can perform live voltage tests. What I would do at this point is isolate the two legs of 120v going to the element. Check to see what leg is not getting to the element and trace back, a wiring diagram at this point would be very helpful. Normally the thermostats and the thermal fuses are all on the same leg and the other leg comes off the drive motor, I've seen it many times when the switch on the motor was the problem.

 

[ddawg16]

sounds like you have a pretty good knowledge of what to check and how to check it so I feel fairly confident you can perform live voltage tests. What I would do at this point is isolate the two legs of 120v going to the element. Check to see what leg is not getting to the element and trace back, a wiring diagram at this point would be very helpful. Normally the thermostats and the thermal fuses are all on the same leg and the other leg comes off the drive motor, I've seen it many times when the switch on the motor was the problem.

I concure....

I just wanted to add that the wiring schematic for that dryer is most likely stuffed inside the control head of the dryer.

Your going to have a relay in there that actually connects the 240 to the element....it might do both legs or just one...but like hard said, you sound like you have a good grasp of the basics...so find that schematic and have at it...

 

[tlgarrison]

Thanks for the tips. That is exactly what I thought I should do next but was not sure where the schematic was located. I will check the in the control head to see if it is there and check if I can follow the flow of current through the circuit.

 

[tlgarrison]

Sorry this has taken so long for me to run this test but I had to find the correct schematic and then try to make sense of it....

I have traced the flow of current using a live test.

1) at each post of the thermal fuse 123.5 V
2) at the low heat thermastat (under the thermal fuse) 123.5 V on both posts

3) High temp thermostat on Heating Element = 123.5 V on both posts

4) both posts on the heat element were 123.5 v

5) Thermal Cut-off - lower post 123.5 V on upper post 13.5 V (something wrong here right!)

Now my question is if the upper post on the thermal cut-off is not correct does that mean that this part is bad? (continuity test was good) Or could it still be the element? I thought the heat element was 220 V but I got 120 v on both posts..

What do you think. And thanks for your help.

 

[hardwareman]

you need to isolate each leg of the 220v to do these test.

 

[backstromben]

I have two suggestions. The first is to double check your breakers. Is it running the correct amp? Has anything change with your box since it was working.
The other suggestion is to use your voltmeter and check the temperature switch (you know regular, extra super fluffy)...check the continuity of that bugger.