Intertherm Intermittent Fan

[bryan]

I have a Nordyne Intertherm single package heat pump and within the last month the fan that pulls air across the radiator has been working intermittently. When running, the unit works fine and blows cold.

So far I had a technician come and look at it and declared it within spec and did nothing. It worked fine while he was here. He did try and tell me that it was low on "freon" but I asked him to check the pressure and he acknowledged that levels were fine. He seemed really bent on wanting to sell me a new unit. I then replaced the contactor as the old one had the cover removed and it may have been an issue with the previous owner. However, that did not fix the problem. I also checked the capacitors and they are fine.

Upon calling the technician back he stated that the defrost board most likely needed replacing. When he quoted me $450 I thought I would see if I could find one on my own. Problem is, I cannot find a model number anywhere on the unit. It does have the Heating Module Kit HMEE-008, 010.

I see that you sell the defrost board and was wondering if you would be able to help me determine if it will work with my unit. Below are links to pictures of the unit.

Thank you for your help.

Bryan

Normal - http://video.dvrdns.org/ac/DSC04537.JPG
Open 1 - http://video.dvrdns.org/ac/DSC04530.JPG
Open 2 - http://video.dvrdns.org/ac/DSC04529.JPG
Open 3 - http://video.dvrdns.org/ac/DSC04531.JPG
Wiring - http://video.dvrdns.org/ac/DSC04532.JPG
Defrost Board - http://video.dvrdns.org/ac/DSC04534.JPG

[bryan]

Also, does anyone know what the consequences would be of leaving the test jumpers shorted?

Any help would be most appreciated.

Regards,
Bryan

[Robert]

Hi Bryan,

If the test pins are left jumped too long, it will reverse back to heat mode and end defrost.


Will check tomorrow and see if the board we have will possibly work.


Model number should be on a data sticker or nameplate, may be faded.


Is it the blower fan motor or the condenser fan motor ?


Both pull air across a coil.



Thanks,
Robert

[Robert]

Hi Bryan,

How did you check the run capacitors to know they were fine ?



Thanks,
Robert

[bryan]

Hi Robert,

Thanks for the reply. Neither the technician or myself could find a model number. There is a sticker on the outside that is so faded that only faint lines from a grid could be seen.

I checked the capicitors by discharging them, connecting a multimeter and performing a continuity check, then read the voltage to see if they took from the meter. Which they all did at half a volt. So, they do hold a charge.

The fan in question is the condenser fan. Sorry about not being more specific. Air is blowing inside the house, just warm air.

Again, thank you for your help.

Bryan

[bryan]

Also, I have another slightly off topic question about heat pump operation and it's controls.

About 4 years ago I installed a programmable thermostat replacing the original mechanical controls. Do these new programmable thermostats provide redundant short cycle protection for these older units or perhaps take control of or circumvent that of the defrost board?

Thanks,
Bryan

[Robert]

Hi Bryan,

The run capacitor can take a charge, discharge, not be swollen and not leaking and still be bad due to producing low microfarads.


Run caps go bad and are fairly cheap anyway, so I would replace it and see. If still bad, you'll be a step ahead when it does fail.


Some t-stats have a built in ASCT (anti short cycle timer) and others don't and no, it won't take the place of the defrost board.


You can trace the motor wires back to their connection points and test to see if the motor is getting 240vac.



Thanks,
Robert

[bryan]

Hi Robert,

The run cap is reading 6.9μF and is rated at 7.5. I will plan to replace.

Yes, the motor is getting the 240v it needs. I'm just not seeing the 24v at the contactor. But again, this is intermittent. I can read the 24v at the times it does decide to work.

I do appreciate your help Robert. Have you been able to identify the unit model from the pictures? I do have more and can provide individual component model/serial numbers if needed. Just nothing for the unit as a whole as it has been lost to the effects of nature.

Thanks,
Bryan

[Robert]

Hi Bryan,

Test at contactor for 24vac across, then test each side to ground.

When you do not get the 24vac, back up to defrost board and see if you have it there, just trace wire back to board.


Getting in neighborhood on model. About how old is it ? Give me the model number of the compressor.

Will be on a tag or stamped onto compressor dome.


Thanks,
Robert

[bryan]

Thank you Robert. Sorry I've been away. My father had emergency surgery so I needed to travel to be with him.

I will try and get the compressor model # later today or tomorrow. We have lived here for 6 years and I can only guess at it's age. With that I will say maybe sometime in the early to mid 1990s.

Regards,
Bryan

[Robert]

Hi Bryan,

You're very welcome, happy to help. Sorry to hear about your Dad, prayers asked for him and your family.


I'll be here when you're able to get with me.




Thanks,
Robert

[bryan]

Good news on multiple fronts.

My father's emergency was piercing pain and numbness in legs from a broken disc in his lower back caused by a fall. Surgery went great and he is already walking again. Thanks for your thoughts.

On to the defrost board. Solved. Pulled the board off completely and noticed a cracked trace going to a lead for the 24vac out. A touch of solder and everything works normal again.

Robert, I really appreciate the time you have taken to help me with my problem. You provide a wonderful service and I have gained a much better understanding of how these units work. Something like this is never thought of much until it stops working. It is nice to know that there are people out there that are knowledgeable and willing to help. Keep up the good work.

Sincerely,
Bryan C. Jordan

[Robert]

Hi Bryan,

You're very welcome, happy to help. Great news about your Dad, glad he is on the mend. Also glad you got everything taken care of and are enjoying the cool.


Take care and best wishes,
Robert