Goodman furnace with 4 blinks, but NOT limit switches!


  #1  
Old 03-03-13, 04:22 PM
V
Member
Thread Starter
Join Date: Mar 2013
Location: USA
Posts: 8
Upvotes: 0
Received 2 Upvotes on 2 Posts
Goodman furnace with 4 blinks, but NOT limit switches!

Hi everyone, I have been reading these forums for a long time and usually get all my answers from previous threads, but I am stuck here.

I have a Goodman gas furnace that has the four blinks error on the LED on the control board. That usually means an open limit switch. HVAC guy that came out came to the same conclusion, so I bought all new replacement switches since I wasn't sure which one (3 in the burner area, 1 in the blower area).

Oddly, before replacing any of them, the furnace would work for 3-4 days just fine then I would wake up one morning and find the blower pushing out cold air, go downstairs and see the red light blinking. Opening it up and just "jiggling" and moving the wires on the control board seemed to let it run a few more days.

This morning, after having the issue again, I replaced ALL the switches in the furnace, turned it on and immediately got the four blinking lights. Confused and angry, I did the normal things: unplugged the connections on the control board / PCB and plugged them back in. When I turned it back on, it fired up correctly, flames and all. This time though the time between "four blinks" is much shorter - the furnace only ran for a couple hours before it happened. "Jiggling" the wires on the control board resulted in heat...for another couple hours.

I am totally lost here. I checked the wires and they all seem fine; nothing looks worn or that it might be shorting, etc.

The PCB is a "PCBBF112" - looks like this one here: Goodman Amana Furnace Control Board PCBBF112 PCBBF112S

I'm not sure if I should just try to replace the PCB or maybe try to completely re-wire the current one first; remove and remake all the connections.

Any thoughts? I am stumped!!
 
Texasman voted this post useful.
  #2  
Old 03-03-13, 04:27 PM
V
Member
Thread Starter
Join Date: Mar 2013
Location: USA
Posts: 8
Upvotes: 0
Received 2 Upvotes on 2 Posts
The only other information I can think of that might be related is that the fan motor and drum are a bit noisier than normal. I was told the bearing on the fan is going bad and because of that there is a bit more vibration, thus the noise. The PCB is attached to that drum, but the vibrations are VERY minor in my opinion so I can't imagine that would be causing any issue on the electronic circuit board.
 
  #3  
Old 03-03-13, 08:32 PM
hvactechfw's Avatar
Member
Join Date: Jan 2011
Posts: 5,491
Upvotes: 0
Received 4 Upvotes on 4 Posts
replace the filter lately? All registers/returns open and not blocked? Model number of furnace?
 
  #4  
Old 03-03-13, 09:32 PM
V
Member
Thread Starter
Join Date: Mar 2013
Location: USA
Posts: 8
Upvotes: 0
Received 2 Upvotes on 2 Posts
Goodman GMS9 or GCS9 according to the warranty sheet.

I have replaced the filter yes and even tried running without one for the last hour but it still failed.

All registers are open in the house. What would that affect?

Thanks for any suggestions!!
 
  #5  
Old 03-03-13, 09:34 PM
hvactechfw's Avatar
Member
Join Date: Jan 2011
Posts: 5,491
Upvotes: 0
Received 4 Upvotes on 4 Posts
you very well may have a failed control board.
 
  #6  
Old 03-03-13, 09:35 PM
V
Member
Thread Starter
Join Date: Mar 2013
Location: USA
Posts: 8
Upvotes: 0
Received 2 Upvotes on 2 Posts
Also I just noticed if I put the thermostat to "off" the red light on the furnace stays solid. Almost immediately after switching to "heat" it enters the four flash error.
 
 

Thread Tools
Search this Thread
 
Ask a Question
Question Title:
Description:
Your question will be posted in: