Replacement for Honeywell Furnace Fan Control Circuit Board ST9120C4057

When my furnace blower motor stopped working this winter when it was starting to get cold I had to fix it right away! I noticed a buzzing coming from the furnace when it wasn’t turned on the heater would run but not hot air was coming out of the vents then the burners would shut off with no heat coming through the vents. I replaced the capacitor first but no luck then I ordered the furnace transformer and circuit board. There was no sense just ordering the circuit board with out the furnace transformer because if the transformer was bad and there was a volt surge then guess what it would burn out the brand new circuit board. I stripped and replaced all loose or damaged terminals and grounds and installed the old terminals using the old board as a guide. Once i got the old boards off it was obvious what the problem was capacitor R11 and R32 along with a relay was burned out causing my furnace blower motor not to work. The Ac guy wanted $2700 to fix the furnace when it only cost me $300 with the new circuit board capacitor and transformer way better then paying someone $2700 I just do not understand how HVAC technicians can do that to little old ladies or folks that simply do not know any better. The photos of the old board will explain everything my recommendation is to change out all these parts at once because they work in unison with each other as safety’s to prevent voltage surges during storms and blackouts.

It's 111 degrees outside here in Vegas and this small board saved the day. Ordered on Saturday and it arrived on Monday.Take tons of pictures before you disconnect the old board. Move one connection at a time. Take your time b/c you are saving $500 not calling a Pro. MAKE SURE the power is off. The board is laid out the same but it's easy to mix up where the connections went. This matched my ST9120C4057 perfectly. This takes little to no skill to replace. Just get a small electrical tester to MAKE SURE there's not current in the wires you're moving.*the little clips that hold the board to the unit probably won't fit. This board had deeper holes that the old one so I zip-tied it in place. Off to Home Depot to see if I can find longer ones.Love you DIY Liquidators. AC is better than gold and your board saved the day.

Item worked perfectly

One cold morning I had that wonderful burnt electrical smell coming through the vents. The next discovery was that the furnace was no longer blowing hot air. I removed the control board and found that the fan relay had burnt out. I got the part number off of the board and typed it into Amazon search.With the exception of the mounting points, this board seems to be an exact replica of the Honeywell ST9120C4057 control board that was in my furnace. I followed the advice of another reviewer and used some plastic drywall anchors with screws to mount it. It works just like the original and I was able to fix my furnace in about 20 minutes.

Part arrived and like everyone else said it didn't fit the plastic mounting brackets that were on my unit. Not a big deal, I just popped those off and used some small bolts and little plastic wall anchors in place of nuts because I didn't have any extra lying around. The part did have a couple extra slots to receive wires that my old board didn't have, but that wasn't a problem because everything was labeled the same on the new board. Take pictures of the layout of the wires before you transfer them to the new board and just go 1 by 1 and it's easy. If it ends going bad I'll update. 4 stars because I paid for expedited shipping and it didn't ship from the merchant til the day after I ordered it...I mean come on the thing weighs like 2 oz's.

Fitment was a little funky but my furnace is quite old. It kis working like a champ since installing..

Perfect

Replacement for my HW model ST9120C4057/HQ1011927HW. The board come with hollow metal spacer. So I have to improvise be removing the original plastic spacer and use screw anchor that fit the hole. The screw for the stat terminal are not metal so I can not do a jump testing. Overall I am satisfied with it.