Repairable heat-exchanger

[Bain]

I found this--quite easily for obvious reasons--cracked heat-exchanger in a furnace last week. Today, the HVAC tech called with questions about a second furnace with minor problems and said he was going to replace the "face plate" of the furnace in the photo. I asked him a few questions to make certain we weren't miscommunicating, and (I think--we were, after all, talking via phones) he maintained that what I was looking at was not the actual heat-exchanger but a replaceable plate. I was able to penetrate the crack +/- 1/4" with a screwdriver, so I'm finding it difficult to envision that portion of the furnace as replaceable.

John

[Bain]

The photo didn't upload for some reason. Here it is.

Download Attachment: DSC01180.JPG

577.86 KB

[kurt]

Depending on the mfg., the face plate should be replacable. The cracked component is a face plate; the heat exchanger is the "tube" behind it.

[Bain]

So the tech likely knows what he's doing, huh? There's a photo of a failure in the Heat Exchanger Expert manual that practically mirrors the one I uploaded.

[kurt]

Well, again, it depends on the mfg. & such, but a lot of those face plates can be changed out.

[Scottpat]

I concur. I found an almost identical crack on an inspection last week, it was a on an old Rheem unit. Some how they found another face plate and replaced the cracked one.

[Bain]

Thanks as always, Kurt and Scott.

John

[MechAcc]

What is the manufacturer and model number of this furnace?

Granted this is a faceplate, however you have streaking upwards above the burners. This is could be an indication that the gas valve is delaying shuting off after the inducer has turned off, a possible restriction in the venting system or there is a crack in the heat exchanger. If this is a clamshell heat exchanger and it is a Goodman , looks like Goodman burners, most likely the crimped rings that secure the two halves of the clam shells together have separated.

One note. If the vestibule panel of a heat exchanger is cracked the local governing authority has final approval whether patch plates from the manufacturers may be used.

[kurt]

Good points. The face plate is kind of toasted; it would be smart to find out why.

[Bain]

You're right, of course, Gary. But the service-people who come in behind me and others seldom possess your level of expertise. Independent thought is becoming a lost commodity. How many service techs would you expect to ask the same questions you did in your post?

John

[MechAcc]

Originally posted by Bain

You're right, of course, Gary. But the service-people who come in behind me and others seldom possess your level of expertise. Independent thought is becoming a lost commodity. How many service techs would you expect to ask the same questions you did in your post?

John

Not the plug and go techs.[:-paperba

[MechAcc]

By the way Heat Exchanger Experts name was brought up. He has new schedule for this September if anyone is interested.

http://www.heatexchangerexperts.com/schedule.html