# Carrier furnace control board - OEM or ICM ?



## anku (Jun 18, 2009)

Hi,

We had a thunderstorm and after that both of our ACs stopped working. Called a service guys, who says control board has gone bad. Thermostat seems to be calling right voltage. Since they are asking ~$900 for 2 board replacement, I am planning to do it myself. I have electrical educational background..hopefully it shouldn't be that bad.

Carrier board part number is HK42FZ009, which seems to be replaced by carrier board number 325878-751. I found couple of guys selling this board on ebay. I see OEM board, replacement OEM board and ICM282 board. Could you please help me identify which board is supposed to be best. From price point they are pretty much the same with little difference.

I really really appreciate any helpful pointer you can provide.

Thank you!


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## beenthere (Oct 11, 2008)

OEM.

Most people get confuse with the ICM board.


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## anku (Jun 18, 2009)

Thank you very much 'beenthere' for the response. Much appreciated. I plan to order them. I plan to post my progress or issues 

Once again thanks.


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## SKIP4661 (Dec 3, 2008)

Personally I would use the 751 board as it is an upgraded board from carrier. The 009 board is an outdated board. The last board Carrier made in that style was the 016, the first was 003. 003 to 016 and they couldn't get it right so they redesigned it with the 751.


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## anku (Jun 18, 2009)

Thanks "SKIP4661" for your comment. I did ordered 325878-751 OEM board. I should receive them by mid next week.
I hope these boards are easy to replace. Does anyone have experience doing such replacement ? Should I pay special attention to anything other than normal safety procedures like switch off supply before work etc ???


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## beenthere (Oct 11, 2008)

Read the instructions.

Then drink a cup of coffee.

Then reread the instructions again.


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## anku (Jun 18, 2009)

*Installed - AC working*

I just wanted to update on my control board work, so it could benefit someone else in the future.

I did looked around the web for 325878-751 OEM control board. Price varied from $115-350. Lowest I could find was at ebay search. Later I ordered through one of those vendor @ $115. Since I needed to replace control board on both of my ACs, I spent ~$245 for 2 cards(including S&H).

While I was waiting for the part to come, I found the instruction manual for this card at :
http://www.kylebellamy.com/transfer/weathermaker9700replacementOCR2.pdf

I familiarized myself with the instruction, while I was waiting for the card. Replacement card comes with wiring harness and instruction manuals. Some of the steps in the manual may be confusing initially but when you read it along with the circuit diagram (which is usually found at/or inside AC panel door), it is easy to follow. Original AC manual(if you are lucky) also has circuit diagram and lots of useful information in it.

My cards finally arrived yesterday. After work I started working on it and it took ~1hr each for me to finish the replacement. Instead of removing all wires from the broken card(as it says in the instruction manual), I removed wires one by one and connected them to new card. One of the wire from AC door panel switch was short, so I had to make a trip to home store.

After reconnecting all the wires, followed the instruction to short 'COM' to 'TEST'. Boards self-test completed as stated. Closed the door and voila !!!

Both of my ACs are working normal now. It was fun and empowering project for me. And not to mention I saved lot of money. AC companies around here quoted $450-600 to replace one card i.e. >$1000 to replace 2 cards.

Once again thanks 'beenthere' and 'SKIP4661' for your comments.:thumbup:


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## anku (Jun 18, 2009)

Hi,
I have left the 'blower off delay' setting to 120 seconds (which is factory setting). My original AC manual(from 10 yr back installation) seem to suggest 90 seconds delay. I figured another 30 second will be beneficial.

Does anyone have opinion about that ???
Thanks


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## beenthere (Oct 11, 2008)

In heat mode you could get some cool air at teh end of the blower cycle.
in cool mode it could add some extra humidity back into the air.

Other then that, nothing harmfull.


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## anku (Jun 18, 2009)

Once again thanks 'beenthere' for your comment.

Have a good day !!


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## dsw40291 (Jul 14, 2009)

*Help w/ICM board*

I could only find the ICM board locally and have it all done except for two wires. The COM wire does not fit on the new ICM board and I can't find the place for the PR2. Any suggestions???


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## dlazart (Jul 19, 2009)

*Same point electrically*



dsw40291 said:


> I could only find the ICM board locally and have it all done except for two wires. The COM wire does not fit on the new ICM board and I can't find the place for the PR2. Any suggestions???


L2, PR2, and Com are all the same point electrically. Also called the "Neutral" which is the White wire in the single phase AC service. They should all be close to the L2 which is near the LED.


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## low2500 (Nov 6, 2009)

*Control Board ICM282 325878-751*

I replaced the original with this ICM282, the AC works great but now, the heat won't come on. Any suggestions on what could be wrong with my wiring? I like to start with the most obvious.
Thank you.


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## anagoree (Oct 13, 2012)

I had exactly the same problem. Thanks to other members for sharing information. I could able to fix the problem exact as it is described above.


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