Armstrong Furnace Blower Control Circuit Board (# R40403-003)

Furnace model: Armstrong Ultra SX 80 (Model number GUJ075D14-1AControl board: Honeywell ST9120A2004 (Armstrong part R40403-001)About a week ago, the furnace inducer motor began cutting in and out at the beginning of a heating cycle. A few days later, the furnace wouldn't even begin to start. A look at the control board determined that it was the problem. Various HVAC contractors wanted north of $550 to replace the board, so I decided to look into replacing it myself. For $70, this board is a steal in comparison.Installation:Replacing the board was simple. Before anything else, turn the power off to the furnace at the breaker. I just unscrewed the board from the furnace, leaving everything connected, and moved one lead at a time from the old board. For those with older boards (other reviewers have mentioned this), you'll need to make sure you've connected the transformer leads correctly. The new board has three leads for the transformer section, one labeled C and two labeled X. The X lead coming off the old board needs to go to the X terminal labeled XFRMR.After checking the wiring diagram included with the board and adjusting the DIP switches to match the old ones, I turned power back on, cranked up the thermostat, and the furnace fired right up.Conclusion:This board works exactly as expected and saved a ton of money. The amount HVAC contractors want for doing the same thing is nothing short of obscene. Don't be afraid of trying this one yourselves, you wallet will thank you (and, in my case, my very cold wife).

After searching FOREVVEERRR for a replacement board for my 13yr old furnace by model number and board numbers, I was about to give up. It doesn’t exist… then I saw reviews about the same furnace here, just slightly different boards and different model numbers and took a chance. Bought it and it delivered. A few days after delivery, my actual board finally craps completely out and there is no fixing it.. now I took a chance and swapped it. BOOM it worked perfectly! No issues and it’s practically plug and play! The diagram/instructions were spot on great and I was so pleased with the time, money and frustration this saved me on my new house purchase! Thank you so much for making and selling this board!!!!!

Had a version 1 and limped through the last winter. Replaced with this new one and fired right up and noticed difference right away.Replace one wire at a time, and no issues. Saved considerable money over hiring a professional to do the same job!

Works like a cham. Easy to install, but I am adding an outlet instead of direct wiring so that I can put in a surge protector it

Attached picture shows both old and new boards, side-by-side. My furnace is back up and running perfectly. Order process was flawless, I highly recommend this company!

I bought this to replace the board on my who-knows-how-old furnace. I had my wife’s cousin install it for us since he does a lot of HVAC work (part of his profession) and I’m not very familiar with this stuff. It seemed to be a very straightforward and simple swap out and didn’t take him long at all.The new board has been working fine and seems to have fixed part of the trouble we had. I would recommend this item.

The board was shipped quickly and arrived with proper packaging. The installation was well documented and easy to accomplish.

I was experiencing intermittent failure. My furnace would go through the start-up cycle and then shutdown shortly after the blower fan started. It would then make several clicks, trying to start but would eventually shut down. I could get it running by jiggling the wires and putting pressure on certain parts of the board, but even those measure eventually failed, so I had to spring for the new board.This board was almost a direct replacement for my furnace (Armstrong Ultra SX 80). There were a few extra connections on the new board and due to my mistake, I blew the 24V transformer. Caution to any prospective buyers of this board. The board works great but when installing it, be aware that there are 3 connections for the transformer instead of 2 on early versions of the board. 2 of the 3 on the new board are (X) or load and the other one is (C) or ground (Neutral). Be careful when installing making sure to connect one lead to one of the X's and one to C. I made the mistake of connecting both transformer leads to both X's; and that literally smoked the transformer - I had to buy a replacement. Once you get over that hurdle, the board has worked without skipping a beat.

This part arrived before the tracking was updated, which is great (it was estimated to take over a week originally)! Works perfectly either my old Ducane furnace and got it running!

A relay went on my Ducane furnace so needed to replace the printed circuit board. item arrived quick. came with instructions. replaced and works great. recommended.

Took me 8 minutes to transfer all the wires from the old board to this new one. Turned on the furnace and it has been working flawlessly. Love it

Bought this for Armstrong SX 80 with loose resistors, blower stopped working properly. After reading reviews, purchase this board, it arrived quickly and well packaged. Based on reviews, had the old board disconnected ,and removed / transferred one wire at a time. Works perfectly.

Item arrived quickly from the USA, works great.