Help on a 1980 carrier

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Originally Posted by tmryan1012

That was my next option. I know it should have been done first but it is cast and the high limit isn't tripping.

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I'm not following how the pressure switch being "cast", and the high limit "not tripping" are related?

anyway..........

be sure you test it (the pressure switch), before you replace it. Remember, a VOM and manometer are your friends.

I had this same issue last year. system may have been running this way for years. I too replace and checked everything,and was also working with "Tech support". I finally advised customer to get an authorized Carrier Dealer tech to take a look at it. He called me back a few days later to a bid on a new furnace..,he said they could'nt figure it out either! The moral of this story.,5hours labor..,3 trips..,did not make a penny! And the "Bid" didnt get it! Good Luck!

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Originally Posted by rundawg

I'm not following how the pressure switch being "cast", and the high limit "not tripping" are related?

anyway..........

be sure you test it (the pressure switch), before you replace it. Remember, a VOM and manometer are your friends.

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I think he means the heat exchange is cast. And since the high limit is not ripping he didn't check the HE.

Well I think my plan of attack is to recheck the pressure switch again and recheck the high limit switch again. Im also going to pull the blower motor and control board so I can slide inside the bottom of the unit to see if I can see any part of the heat exchanger. Thanks for the help. I will let y'all know how it goes.

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Originally Posted by beenthere

I think he means the heat exchange is cast. And since the high limit is not ripping he didn't check the HE.

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Got it. I stood up on my chair and it finally sunk in what he was saying. :)

Thanks.

I was standing on my toilet when I finally got it.

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Originally Posted by philjafo

I was standing on my toilet when I finally got it.

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Seat up or down?

im gonna guess its the fusible link. that breaks one of the wires to the three wire pilot.

Seat down of course, last time I was high on pot my foot slipped and went into the bowl had to spend the rest of the day with a stinky shoe. Not fun

whut da hayell?

Won't be the fuse link, that puts blower into continuous operation and nothing else.
hmm got to think a bit. Have you tried bypassing thermostat?

Loose/bad/pooe groundr

sorry, if I sound like an idiot, but no way in hell I would be liable trying to fix a 1980 carrier furnace... No way I would drive away from that thing knowing nothing bad could happened after I touched it...

I would replace it, or have someone sign a non warranty/non liable agreement... I am guessing this a joke/troll thread or something...

After that said, I would not be suprised if its shutting down due to some kinda safety switch.. Lack of CFM, etc.