Replacement of Heat Exchanger in Goodman GMP100-4 Furnace

Old 12-08-13, 01:12 PM
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Replacement of Heat Exchanger in Goodman GMP100-4 Furnace

I would like to replace the heat exchanger in my Goodman GMP100-4.
The new Goodman heat exchanger is $200 delivered.
I have recently replaced both the blowers, so I don't want to buy a new furnace.

The removal and replacement looks "straight forward".

(1) disconnect the gas line and remove the gas valve controller and burner box assembly,
(2) remove the air pressure switch assembly,
(3) remove the flue collector box and flue venter blower,
(4) remove the old heat exchanger and replace.
(5) reassemble

Other than disconnecting the gas line, everything else involves machine screws and a few electrical connectors.

So what am I missing? As long as I photo detail all disassembly steps, and put back together using the same steps in the reverse order how can I screw this up?
Old 12-08-13, 04:55 PM
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It is pretty straight forward. You need to be careful to get all gaskets in place & keep them intact. Coating gasketed surfaces with an anti-seeze compound helps to hold gaskets (especially on vertical surfaces) in place while screws are installed.
If you want to do this yourself, I strongly urge you to have a local pro with electronic combustion test equipment come in & fire the furnace.

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