I put a new board in a GMP070 and the inducing fan motor kicks as normal, then the HSI starts to light but the whole board goes dead within 3 seconds.

When you say the whole board go dead what do you nean?

Does the blower motor not start to run, does nothing show up on the fault code indicator?

When you unplug the furnace and re-plug it in does the furnace try to start up again and then cut off after the 3 seconds?

I have one thing for you to try and that is to clean the flame sensor if you have not already done it. If you don't know what it is, it is the wire post sticking up in front of one of the burners, it has a ceramic bace and it atached to the furnace with one wire screwed to the furnace body . Take that screw our and use a fine sand paper or clothe and clean the wire, Replace the sensor and try the furnace again.

If it does not work let me know.

The led goes out and everything shuts down. Inducing moter, HSI and all.The led does not display a code at all.

When you unplug the furnace and plug it back in what does it do? Describe it to me.

Sounds like a board problem, double, triple, and quadruple check the wiring of the new board. Hope like hell you haven't fried the new board by installing it incorrectly.

What was the reason for replacing the board? Was it doing the same thing before board replacement.

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Originally Posted by letmetellu

When you unplug the furnace and plug it back in what does it do? Describe it to me.

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It starts normally with the inducing fan motor kicking on. Then after a few seconds the HSI starts to ignite but then the whole process stops. The LED goes out and nothing works until I reset it.

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Originally Posted by mygirlsdad77

sounds like a board problem,,double, triple, and quadruple check the wiring of the new board. Hope like hell you havent fried the new board by installing it incorrectly.

What was the reason for replacing the board? was it doing the same thing before board replacement.

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I checked the wiring before I energized it. It is wired right. I replaced the board because the furnace was strting noramlly but shutting off after the flame sensor should have dtected flame. I replaced the flame sensor and the problem was exactly the same.

It sure does sound like the flame sensor is or was the problem all along. Because it is acting the way it should except in a normal situation the furnace would try to light three to five times, depending what model of furnace you have.