Author Topic: b6 error code on Amana Furnace  (Read 400 times)

Offline Sergroum

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b6 error code on Amana Furnace
« on: July 24, 2018, 01:05:18 AM »
Hello, hello.

So  I have a case I've never encountered before. I wonder if anyone have. 

So I have a house under reno where an electrician have done something weird and wonky. I dont even truly understand how did he manage, but somehow he managed to burn out a fridge, a tv, a gas valve on a HWT, and the electrical board on an amana furnace.

Changed the gas valve and changed the board. Now they all work, but the the furnace runs the blower for about 40-60 seconds and then stops, showing me b6 error code.

GMVM971005CNAA
Furnace.

This is not a GMVM96 type of furnace, where you need to insert a certain module into the board when you change it. At least that model is not mentioned in the list. b6 error code means that blower stopped working due to either too high/too lower AC voltage, or high temperature.  I was reading the voltage during operation and it stayed consistent 122-124.

Any thoughts on what happened? It's an ECM motor. Did something melt during the whatever power surge the electrician created? Something that kept the motor in operation, but is making it overhead? I'm puzzled.

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Re: b6 error code on Amana Furnace
« Reply #1 on: July 24, 2018, 05:55:45 AM »
Maybe you need to adjust the dip switches on the control board to lower the fan speed.  Sometimes if ductwork is undersized I have seen the ECM fan cause a lockout.

Otherwise there's still something going on with the power supply.  Did you measure voltage between neutral and ground?  I'm surprised you didn't have to replace the thermostat as well, but there's a good chance you have a faulty ECM motor.

I found this bulletin that does mention a memory chip on the control board.  You can download the SF-055 bulletin - Here

Offline Sergroum

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Re: b6 error code on Amana Furnace
« Reply #2 on: July 24, 2018, 08:23:32 AM »
Yeah. Those memory chips are for the furnaces of 2013, or older. This one is 2016. The board comes with a bunch of those chips included and a manual that explains which chip goes to which model. None of them mention this furnace's model and the serial first 4 letters are different as well.   I dont think it's the chip. And if it is, then the manual's off.

I tried lowering the rpm down to the lowest setting, same thing is happening. I fear it's the faulty ecm  motor, I just dont get how.   


And yeah! I was surprised the tstat survived. It wasnt one of those communicating ones. An ecobee3.

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Re: b6 error code on Amana Furnace
« Reply #3 on: July 24, 2018, 08:25:49 AM »
I think the fan motor is the problem as well.  It likely got hit when the same power surge.

Offline Sergroum

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Re: b6 error code on Amana Furnace
« Reply #4 on: July 24, 2018, 08:27:48 AM »
I didnt measure between neutral to ground though. Measured between line and ground during operation though. Hrmh.    Would this be significantly different? I've had cases where due to the carbonization of the line connections at the breaker, voltage would drop during load increases. While without the load, it read steady 120.  but I thought you caught that by measuring line, not neutral.

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Re: b6 error code on Amana Furnace
« Reply #5 on: July 24, 2018, 08:51:41 AM »
It sounds like your power supply is good.  It's just something I always like to check, but it doesn't seem to be the problem in your case.