new customer found heat exchanger bad and furnace over heating on goodman package unit. Fourth heat exchanger in 10 years and still over heating. Duct out correctly, fixed insulation that had fallen and still over heating. 150,000 btu with limit of 165 and temps running over 200. any suggestions on what to try next to avoid replacing the heat exchanger again?
Are there pics?
is it natural gas or propane? Did you check the gas pressures coming out of the gas valve?
Try posting this these questions on the commercial HVAC section if you really want answers to your questions most of what you will find in this section is pics of installs and service gone wrong
If we didn't do this what would we do for fun?
The duct is correct? I say you check the duct to the unit not the house. I think you will find it is too small. “yea, put that 3 ton furnace on that 2 ton duct and drop the fan speed, it’ll heat up better right”. not not not not for long.
Also the bottom of the exchanger gets no airflow from the top blower input to the exchanger area. Some down facing vanes will help get the air to the front bottom corner where it is needed badly.
Yea it sucks that engineers get whopping bucks to figure this stuff, and get it wrong, and then we get to do it right with a little real world experience and no whopping bucks.
Be good to your fellow man, not nice. There is a difference.
either you don't have the airflow or you may have the furnace overfired if the temp is that hot.
any suggestions on what to try next to avoid replacing the heat exchanger again?
Yeah - yank that tub of crap out of there and explain that this is what happens when you try to save a buck.....
The equipment is not at fault here. There is a problem with the application.
Don't they teach Bryantreps how to read or do you just have a problem with comprehension of how HVAC systems work?
Government is a disease...
...masquerading as its own cure…
Ecclesiastes 10:2 NIV
Sorry 'bout that, RoBoTeq! Didn't mean to offend.
1 - No problem with comprehension. Been in this business since 1988, started as a service tech. Bryant didn't have to teach me anything.
2 - It is a commonly known fact that Goodman has had numerous problems of late with heat exchangers. You can't deny that.
3 - They do not try to hide he fact that they build low-grade, low-tech equipment that my 5-year-old can out-engineer. They are actually proud of this.
Believe it or not, I'm not here to bash Goodman. I'm glad they're out there. They exist to fill a segment of the market that I (thankfully) do not have to. I don't want the headaches, and they are more than welcome to it. I'm just sorry they had to take Amana down with them.
I'm not sorry that Goodman ate Amana this is payback for the Energy Command Nightmare Furnace.
Originally posted by bryantrep
I'm just sorry they had to take Amana down with them.
"150,000 btu with limit of 165 and temps running over 200. any suggestions on what to try next to avoid replacing the heat exchanger again?"
Well if it has a limit control cutting burners off at 165 , why is it running 200+, that is your problem , too much heat, heat exhangers can only take so much heat, Higher heat= expansion/contraction of the metals is too conflicting and causes seperation.
Restricted Return ducting
As mentioned, Gas pressure at valve
Correct burner orfice size