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Discussion Starter · #1 ·
Hi this is the second time that my circuit board when bad. Last time it was 2yrs into the life of the unit. That was in 2004 and now it's 2009 and after a bad thunderstorm that trip a few breakers in my house, it is once again dead. I tried to do some diagnostics and decided to call in a professional HVAC guy. He confirms to me that the circuit board is toast. He can make the blower, etc work by bypassing. So now he has to order a new board. Just wondering if anyone has this type of bad luck. Is there something else broken that is causing the board to die after x amount of years. I'm a electrical engineer by trade and this is very disturbing as most engineers would tend to agree in HVAC should virtually last forever. My parents house is 15yrs old and has never has this problem.

Any thoughts from anyone?
 

· HVAC / Plumbing
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are you having some type of power problems at the unit ?? The solder connections have been a problem in the past..I have talked to several reps with honeywell & they told me that when they checked several bad boards that they found cracked solder connections... I thought they had corrected the problems... It is my understanding most of the boards come from south of the U.S.
 

· In Loving Memory
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The electrical storm caused some breakers to trip?

Then you robably got a surge to it.

Electonic boards are NOT built to last forever in HVAC.
Mostly because people wouldn't pay the price for the equipment then.
 

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Discussion Starter · #4 ·
Thanks guys...well what happen is I had 3 breaker tripped. But not to the HVAC. The other strange thing is I have 2 units. Both of them were in the off position. This one unit died. It's just strange to me that the same unit keeps going out when the other one is just fine for the last few years.

I agree with the surge. It's just bad luck I guess.
 

· Hvac Pro
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10 yrs is the average life of a circuit board. In a furnace there is vibration and heat and the relays usually fail from use after 10 yrs. Goodman had some problems with the grounding of their boards. If it is on a metal bracket attached to the fan make sure it is tight and put more screws into the bracket if necessary.:thumbsup:
 

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i have to comment on the statement about hvac lasting for ever, thats a rather funny statement as if they did this forum wouldnt exsist (it also has the highest number of viewers usually) and none of us would have jobs in the field so um... yea last forever im not seeing that. just my 2 cents
 

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this is the second time that my circuit board when bad.
Last time it was 2yrs into the life of the unit.
after a bad thunderstorm that trip a few breakers in my house, it is once again dead.

He confirms to me that the circuit board is toast.
Doing an autopsy on the board will tell you what failed first.


Is there something else broken that is causing the board to die after x amount of years.
There is infant mortality (due to factory defects), there is normal random wearout, and then there is end of life wearout.
http://en.wikipedia.org/wiki/Bathtub_curve

I'm a electrical engineer by trade
My parents house is 15yrs old and has never has this problem.
Put a fuse in series with an MOV [or back to back Zeners] which you should put across the board input.

If you're in Florida you may require extraordinary surge protection.
 

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have an electrician install a block surge supressor in line. that may help ,i put them on as part of my standard installs seems to help i've used them on some commercial stuff i work on that was loosing boards and haven't lost one in about 3 years
 

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During high electrical weather events the static surge transmitted/conducted

thru the air has been known to take out electronics.

15 years with out a repair on an HVAC system is an exception to the rule.
 

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Discussion Starter · #11 ·
Well a technician came to change out the circuit board and we tried the AC because it was hot that day. Everythng worked anh he checked the freon level also. It was stupid of me to not also check the heater. I live in Texas and the weather is as wacky as this Goodman unit. :). One day cold and one day hot. Anyways, it has gotten cold and will get cold. Today I turned on the heat and it doesn't work. Doesn't work mean, the ignitor comes on but the gas doesn't spray and ignite the unit. Ignitor is red as hell. I checked the gas and it's fine. Is there something on the circuit board that the tech forgot to connect ?
 

· In Loving Memory
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Component.

Look for small sensors near the burners. See if any of them are tripped.

Might also be one on the blower housing also.

If any are tripped. You got more trouble then what you though.
 

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Probably an open roll out switch.
Furnaces, 101

"The limit control is a safety device that will open the electrical circuit to the ignition control and stop the gas flow if the furnace over heats. The flame roll out switch does the same thing if the flame was rolling out of the heat exchanger instead of being completely induced into it by the draft inducer."

I never heard of the thing.
http://en.wikipedia.org/wiki/Furnace
http://images.google.com/images?hl=...+roll+out+switch"&btnG=Search+Images&aq=f&oq=
Thanks, Mr. There. . .
 

· In Loving Memory
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Some roll outs, open the circuit to both the HSI and gas valve, and some just to the gas valve.
 

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Discussion Starter · #19 ·
It turns out to be the gas valve. For some odd reason, when the switch closes to send 24V back to the circuit board, it shorts out and blows the fuse. This is what I saw the tech do. I have two units in the attic and to rule out the Circuit board as the culprit, we swapped boards and the other unit works just fine. So now he is coming out to replace the entire piece tomorrow. Any idea how much this will cost? Can the just the switch be replaced or the entire gas valve and switch have to be replaced?
 

· In Loving Memory
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If you mean pressure switch.
Its not the switch that is causing the fuse to blow.
 
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