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Gary Brufach
Gary Brufach, HVAC Technician
Category: HVAC
Satisfied Customers: 12
Experience:  Heating & Air Conditioning Company, Owner, Operator, Installer & Technician
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Have the same problems with Goodman GMPN080-4-Problem started

Resolved Question:

Have the same problems with Goodman GMPN080-4-Problem started with the primary heat exchanger going bad-Goodman has a lifetime warranty but still cost me $730.00 for installation. Two months later the problem with the condinsation and the soot and the failure of the system to stay fired up. HVAC tech states the secondary heat exchanger has only a 5 year warranty. System is 11 years old. Question is did they have to take the secondary heat exchanger out when they installed primary exchanger. I feel that they did and somhow cracked it when it was removed. It seemed that the cooling fins were smashed when it was removed maybe along with the coils.
Submitted: 6 years ago.
Category: HVAC
Expert:  Gary Brufach replied 6 years ago.
Can you describe the problem a little better? Usually the heat exchanger doesn't go bad, that may not be the issue. You said the furnace won't stay fired up?
Expert:  Gary Brufach replied 6 years ago.
Is this system natural gas? Propane? I am just gathering information.
Customer: replied 6 years ago.

System is propane. We had two different service calls after primary was installed because of the failure of the system to stay fired up. The tech stated that the secondary was cracked and showed me with a set of mirrows after he had taken blower motor out. The system is building up condensation and soot.


I feel if the secondary system had to be removed to gain access to the primary that some damage could have been done then. The techs have been trying to sell me with a new unit or heatpump. They said that they could get the secondary within a week and install it the same day. How much time does it take to install the seconday. They charged me 6 hours for the primary. I don't want to throw my money away on a new system-times are tight. The secondary will come with a 5 year warrante on the part.


The question is did they have to remove the secondary to get at the primary?


What is your guesstimate on the amount of time to install the secondary?



With what has been done so far do you think I should wait until the summer to think about new and have the secondary replaced?

Expert:  Gary Brufach replied 6 years ago.
I live in the mountains of Ca, & all we use is propane. Your symptoms point to a bad propane conversion. The black soot is created due to an incomplete burn of fuel, when enough soot builds up on the heat exchanger, it acts as an insulator, which keeps the heat from being extracted from the heat exchangers, which causes them to crack. I am making you aware of this, so that you don't replace more components, only to have them fail due to the same problem. Soot is a dead giveaway, I have changed out 20+ year old propane furnaces, that didn't have a spec of soot on the inside.

Now to answer your question:

Yes the secondary is located below the primary, it has to be removed.

Timeframe varies, I would say 2-4 hours labor, depends on the furnace & the tech!
Expert:  Gary Brufach replied 6 years ago.
I would have the tech, or a different tech (if you don't trust the current one), verify that your orifice size is either 55, or 1.25mm. The metric was usually used in higher elevations. Either one was stated as an acceptable LP conversion, I just looked it up on the Goodman site. You may be able to check yourself, the orfice has the # XXXXX on it, although it is hard to see when the burner assembly is installed in the furnace.
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