Heat works, fan stops too soon

[Eagle85]

Hi, I have an Intertherm/Nordyne model E2EB-D15HA, which has had its share of issues in the past 3 years.

Currently, the heat and fan kick on normally when the T-stat triggers the call for heat and the house heats normally. Once the heat reaches the the appropriate temp, the fan kicks off, but the heat remains on until a limit (or some other safety) cuts the power to the elements. Scary situation for me... as a lot of heat builds in a small area...

For now, when we need a bit of heat, I'm operating it manually to heat the house, cut the heat at the t-stat, and run the fan in the "ON" position until cool air blows from the vents. Obviously I can't keep this up all winter!

I feel that the sequencer (621678?) is the problem, but I'm making an educated guess. Really, I don't trust the local repair companies because they still haven't fixed my A/C in about 10 service calls, but that's another post....

Any ideas? Or am I on the right track?

Also, the transformer is buzzing, which as I remember from my basic electronics class as being a sign of pending failure? Should I replace it as well?

[Robert]

Hi,

Sequencer # 621679 @ $35.00

Transformer # 621814 @ $19.80

Shipping = $14.75


Sequencer is most likely cause of problem and if transformer is buzzing, best to replace now than wait until it fails.


You can see both and order through PayPal from here:

http://www.mobilehomerepair.com/NordyneElec.html


OR, by calling toll free after 9AM CST to 1-877-263-7860 and charging to Visa or Mastercard.


LOL, don't wait until summer to post your a/c woes, now's a good time or better yet, email it to me.


Thanks for inquiring,
Robert

[Eagle85]

Robert,
Thanks for the quick reply.

I'll order the parts today, but I have one last question...

The sequencer on my unit is 621678 (if I read it right while standing on my head), and you quoted 621679. Is there a difference? Or did I just read it incorrectly?

Thanks again...

[Eagle85]

I verified the sequencer when I called to place my order today... the gentleman on the phone was VERY helpful and pleasant... sorry I couldn't remember his name... (Mark? Matt?)

Anyway, I ordered a new sequencer and transformer.

I'll let you know how it works after the parts arrive and I get them installed.

Thanks again.

[Robert]

Hi,

You're very welcome. That was Mark, owner of this website.

621679 is the listed sequencer, but either would work.


Thanks for ordering.



Take care and best wishes,
Robert

[Eagle85]

Sorry this is a long post, but I wanted to capture details for you:

The parts arrived on Saturday, and I installed them right away, taking care to move one wire at a time so I wouldn't mess up and need a diagram

I went to the t-stat and called for heat (80-degrees); the blower and heat popped on like usual and heated the house. When the unit had run for about 15 min, I dropped the t-stat to the temp it was reading, so it would only run for another minute or two. When the t-stat clicked, the blower kicked off, but the heat remained on until the limit switch opened the circuit. So I can assume my original sequencer was probably working. (That's okay, I like to keep spare parts, just in case).

After some investigation with a flashlight and multi-meter (and trying to read the simple schematic on the cover plate), I think I found of the problem - at least part of it anyway.

There should be a wire from the blower motor to the sequencer. A yellow wire was connected to the sequencer, which lead to the blower motor, but it is not connected to the blower motor. I looked at the fan wiring plate and found the BLUE wire was Med-Hi speed. It was not connected to anything, so I connected it to the sequencer where the yellow wire was connected.

Now the unit keeps the blower running for about 2 minutes after the t-stat clicks off, but there is a definite change in fan speed when it does. The good news is that the furnace compartment is now cool after the heat cycle completes, so everything seems to be working in theory. I guess I just need to iron out the blower speed issues?

The blower motor and cap were the only parts that have been replaced in the past (last spring), and I'm sure the service tech wired the blower motor for the A/C function only, and didn't think about the heat....

My question now is what speed should the blower be running for heat (med-hi? what RPMs?)? Shouldn't it maintain the same speed through the entire cycle? What should the speed be for A/C?

I think the service tech wired the heat and A/C to both run on HIGH speed, which is probably affecting the efficiency, if heat should run at a lower speed?

Any help you can give is greatly appreciated... Thanks!

[Robert]

Ok, you may just have a wiring issue. The yellow connected to M1 of sequencer should then go to the blower switch #3.

You then have a yellow from blower relay # 6 to #2 of molex connector which goes to yellow wire from blower motor Med.Lo speed for HEAT.


Cooling speed is black wire from blower relay #4 to molex connector # 4 which goes to black from blower motor Hi speed for A/C.


Blue and Red are unconnected and zip tied out of way.


Hope this helps.


Thanks,
Robert