We recently had ours replaced. It lasted about 28 years! It was not putting out real hot heat when it was working and it was shutting itself off. But it was time for a new one!!!
The installer told us that was due to the lower heat exchanger. They cannot replace the lower heat exchanger easily! The cost of that replacement would be about equal to that of a new furnace?
But that heat exchanger part is indeed a bolted in modular part! If you reach up to your vents and the air seems warm and not hot it is likely due to the heat exchanger. They will tell you that the heat exchanger is warranted for the life of the furnace but then the double talk is that the life of the furnace is really that of the heat exchanger. They will tell you that new ones are made out of stainless steel and last forever. But that isn't true either as anyone who has a gas grill with a stainless steel burner know that they have to be replaced too. The back side to where the heat exchanger could be accessed is all spot welded or light seam welded steel. So you can't get to it without taking the whole furnace apart. When you start to take a furnace apart from the side they are currently taken apart from you will find you end up with broken parts as everything gets “stuck” in place after awhile.
So what is the point? The point is that all furnaces should be made so that the heat exchanger can easily be replaced. A heat exchanger exchanges heat like a cars radiator does but not in the same manner, one uses water cooling to “exchange heat.” Do you remember how you used to have to replace a corroded aluminum car radiator? How cheated would you feel if they told you that your car only had the life of its radiator? You would be beet red in the head and angry right?
So look at the photograph below and you will see how a home furnace heat exchanger fails. It corrodes and that falling rust clogs it! There is also white scale on it that prevents it from exchanging heat? Much like a scaled coffee pot doesn't work anymore. In effect the scale insulates the heat exchanger to prevent it from exchanging heat.
But you should not have to replace a full furnace. That just creates waste! Old furnaces used to have a coating that didn't rust as easily. They were also of a heavier gauge sheet metal.
All this waste creates a future liability. Also the energy that goes into producing wasteful products pollutes. Bottom line is that those who make profits under the limited liability shield really don't earn their money because they are creating untenable future liability costs to humanity and human health!
In the future creating products that create waste could be an act of worldwide treason!
As to the photograph above; I just had to see.
Thomas Paul Murphy
Originally published on 01 21 2016 at: www.themilwaukeeandwisconsinnews.blogspot.com