Heating & Cooling Logo

Related Topics:

Alfredo Lopez Posted on Nov 10, 2018

Replaced Goodman pcbbf112s control board with icm286 control board but it shuts down and led flashes 8 times indicating thermostat problem. Do I need to replace thermostat

1 Answer

Vongrayson

Level 1:

An expert who has achieved level 1.

MVP:

An expert that got 5 achievements.

Greenhorn:

A rookie expert who has answered 20 questions on their first day.

Cheetah:

An expert who has answered 20 or more questions within one hour.

  • Contributor 25 Answers
  • Posted on Oct 15, 2019
Vongrayson
Contributor
Level 1:

An expert who has achieved level 1.

MVP:

An expert that got 5 achievements.

Greenhorn:

A rookie expert who has answered 20 questions on their first day.

Cheetah:

An expert who has answered 20 or more questions within one hour.

Joined: Oct 15, 2019
Answers
25
Questions
0
Helped
14494
Points
32

Remove all the low voltage control wires from the thermostat, on the terminal board there is ,
R or Red = 24 volt "hot leg"
W or White = Heat circuit.
Y or Yellow = Cool circuit
G or Green = Fan circuit.
C or Common = 24 volt "neutral leg"

The R and C terminals are the 24 volt power supply, the R being the hot leg of power, C is the side of power that every 24 volt circuit terminates upon to complete the circuit.
Just as a car battery has a Negative post that all 12 volt circuits terminate upon in a car or anything electrical , they all require 2 legs of power, some voltages are only 1 hot leg 230 volts is 2 hot legs but 115 volts and 24 volts which a thermostat controls uses 1 hot leg being the R terminal.
The thermostat has switches internally that connect the hot leg of the 24 volt power to the desired circuit, jump red to white and heat comes on, jump red to green and fan runs, jump red to yellow and the AC unit outside runs. test this out and if it operates then the thermostat is bad assuming it is wired correctly.

5 Related Answers

Anonymous

  • 42 Answers
  • Posted on Nov 10, 2007

SOURCE: No heat, trouble shooting light has continious flash.

There is a vacuum sensor on most units tied from the exhaust gas fan to the sensor. Does the unit try to start? If the unit's exhaust fails to pull the switch it will turn off after about 30-45 sec after starting. "IT" thinks it's not exhausting and stops to keep from overheating. Do you have this exhaust fan and rubber hose to sensor? Can you see if that fan is turning on start?

Ad

Anonymous

  • 70 Answers
  • Posted on Jan 08, 2009

SOURCE: Goodman GMNT furnace goes into 'lock-out'.

check to see if your intake pipe or vent is clear this could cause a flame jump and make it look like a bad flame sensor let me know if this helps

Anonymous

  • 61 Answers
  • Posted on Jan 10, 2009

SOURCE: furnace starts properly, then shuts down, led flashes 8 times

The first thing to look at is the flame sense rod.
Shut off power to the furnace, remove, clean sensor with steel wool or sandpaper then reinstall the sensor. Reapply power and it should run properly.

Anonymous

  • 2 Answers
  • Posted on Apr 07, 2009

SOURCE: goodman a/c blower fan will not shut off

Pull the stat off the wall, if the unit fan continues to run then your fan relay is bad or receiving 24vac from another source.

gtmerkley

George Merkley

  • 194 Answers
  • Posted on Oct 10, 2009

SOURCE: I have a Goodman GMH95/GCH9 furnace, the

open the front door to the furnace to access the controls there should be a red button try pushing it to reset

Ad

Add Your Answer

×

Uploading: 0%

my-video-file.mp4

Complete. Click "Add" to insert your video. Add

×

Loading...
Loading...

Related Questions:

0helpful
3answers

I have a Goodman GMH95 Furnace. 4 Blink Error code. I have checked high limit circuit and all sensors are working (test closed while cool.) When I turn on furnace, as soon as it recieves signal to turn on...

There are several issues that can cause this. They range from airflow issues to bad main control boards. The airflow is easiest and it goes without saying that the filters should be clean or recently replaced. There have been cases where the controller board has retained that error and you must power off the whole furnace in order to reset it. Sometimes it requires you to replace the control board. The parts place I recommend is Goodman Furnace: Model GMH950703BXAC Parts & Repair Help ' Repair Clinic
0helpful
1answer

Replacing Goodman Furnace B18099-26 with ICM286 fails

decouple the output of the pcb ,put a 10-100nf between the two connectors
0helpful
1answer

I'm trying to install a Venstar T5900 programmable stat to a Goodman GSK91155DXAC furnace with an ICM board. R, W, Y, G, and C are used. Everything works with exception of when calling for heat. An...

Hello, Often times the clarity of the "C" terminal is faint in the instructions. The "C" terminal should be naturally grounded from the transformer. So yes make sure it is grounded. Double check that the "C" is constant from furnace to thermostat to outdoor unit.

Also make sure the furnace is properly grounded.

Holle back if needed.
0helpful
1answer

The fan motor is on all the time with the controls shut off. I have to shut the unit off with the main breaker. The ac works but again the fan never shuts off. On the circuit board the LED flashes 8 times,...

The indoor fan or the outdoor fan? If it is the indoor fan the thermostat may be wired incorrectly or shorted. If the red wire and green wire in your thermostat maintain contact, the indoor fan will run all the time.
0helpful
1answer

I have a Goodman GMH950904CXAC. Thermostat calls for heat. It comes on and runs fine for about 5 minutes, then the circulator blower shuts off, but burners and draft blower still run. After another 15...

4 flashes is an overheat situation most likely caused by the blower not blowing. The blower relay controls the blower function. It is part of the circuit board. I suspect a new board will take care of the problem if you don't find a lose wire or something simple.
0helpful
1answer

Thermostat at 70, shuts off at 62. stays only 1/2 hour at at time

What LED are you talking about that keeps flashing?

If it's the LED on the controller board in the furnace, they blink with a cadence that you need to watch. There will be a data sheet somewhere on the furnace that will tell you what the cadence (flash cadence) is.

Replay back and I can help you more.
0helpful
1answer

Furnace starts properly, then shuts down, led flashes 8 times

The first thing to look at is the flame sense rod.
Shut off power to the furnace, remove, clean sensor with steel wool or sandpaper then reinstall the sensor. Reapply power and it should run properly.
0helpful
1answer

Goodman Furnace m/n GKS90453BKAC

A constant red light (not blinking) indicates that the thermostat is not calling for heat. Of course you know it is but just to be safe, jump out R and W on the board. If it continues to do the same as you indicated, replace the board.
Not finding what you are looking for?

302 views

Ask a Question

Usually answered in minutes!

Top Goodman Heating & Cooling Experts

Paul Carew

Level 3 Expert

3808 Answers

Mike Cairns
Mike Cairns

Level 3 Expert

3054 Answers

Jay Finke
Jay Finke

Level 3 Expert

1397 Answers

Are you a Goodman Heating and Cooling Expert? Answer questions, earn points and help others

Answer questions

Manuals & User Guides

Loading...