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servtech50
servtech50, HVAC Technician
Category: HVAC
Satisfied Customers: 322
Experience:  over 20 yrs. experience
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Have Emerson 4702g furnace control board. The LED flashed

Customer Question

Have Emerson 4702g furnace control board. The LED flashed four times red. What does this mean?
Submitted: 5 years ago.
Category: HVAC
Expert:  servtech50 replied 5 years ago.

servtech50 :

Hello, and welcome to Just Answer. I am servtech50 and will try to assist you today.

Customer :

Thanks

servtech50 :

what make, model and serial number is this control in. The control will be specific to the equipment.

Customer :

The control board currently in the york furnace is an Emerson 4702G. This is not the board that came with the furnace originally. The original boardf was a carrier Model HK42FZ011.

Customer :

The furnace is a ZYork Diamond 80, Model PHUA12N06401B.

servtech50 :

ok, so this must be a universal control? who ever changed out the control did not leave a diagnostic chart behind? or did thy affix it to either door panels? and what is happening with your furnace? can you explain the sequence of ignition to me? what does or does not happen. we may not need to know what the flashes mean if you can describe what is happening.

Customer :

Until yesterday, the unit worked normally most of the time. The board flashed an initial red LED upon starting and then turned green. The problem had been that the unit woulkd go out at a point and not come back on. In trying to diagnose the problem, I clewaned the flame sensor . However, now the unit does not come on at all and I get four red flashed from the LED.

servtech50 :

ok let me see if I can locate the control. I do not understand why this equipment would have 2 different controls installed into it.

Customer :

+The original board was not replaced as I could not buy it because I am not a licensed technician. Therefore I bought the universal.

servtech50 :

i see. I am still serching for your board with a diagnostic code

Customer :

If you cannot find it, that will be OK. I have to leave in about fifteen minutes and will have to consider other options.

servtech50 :

oh I will find it now it is the challenge. is this a spark ignition or hot surface?

Customer :

The furnace has an igniter that heats up, glowing red. The issue here is to determine whether the board itself is bad. I suspect that the four red flashes is saying so, but wanted to confirm.

servtech50 :

ok. I will get you your answer. But it is your choice to exit or allow me to continue

Customer :

I will hang on for a while longer. Thanks

Customer :

I will have to leave at this point. Will get back to you and will compensate you for your trouble.

Customer :

BACK

servtech50 :

hello, I am also back

servtech50 :

I have a call into Emerson they are suppose to call me back 1:38 here if they do not call back bt 2:00 I will recall them

Customer :

OK

servtech50 :

was there any other information on control board?

servtech50 :

while I wait for someone to answer the phone was just wondering...do you bow hunt? I ask because of your user name

Expert:  servtech50 replied 5 years ago.
Good morning, Can you get me any more information off the control board? It seems some numbers are missing. But if I and Emerson were to guess the 4 flashes are for a high limit is open. if you turn heat on does your blower run continuously with no heat?
Customer: replied 5 years ago.

On yesterday I had a local technician come out and he determined conclusively that the Emerson board is bad as I suspected. I will have it replaced. Please discontinue efforts to contact Emerson regarding this. Thanks for the efforts.

Expert:  servtech50 replied 5 years ago.
would like to continue but in order for me to do so, I would need more numbers off the old board. unless you still have board there is nothing more I can do. What did the tech. put in, what brand?