Rheem RRGG HX failures

[slctech]

I know this is not really WOS, but thoughy I might as well post pic's of a very common HX failure I am running into.

About three years ago brought on a new customer with twenty two of these Rheem RRGG RTUs. Over the last three years I have replaced almost all except five. They all fail the same and when they fail they fail BIG.
This is the most recent unit pulled earlier this week.

Already yanked HX but the rust is a dead give away of issues...


Close up of venting side all rusted out.....


8" crack - this is found right where the Fan/Limit Probe extends in to exchanger box. About half the units I have pulled had the exact type of failure.


All the units I have pulled had the following failure.....


Posting the replacement of this unit with a new Lennox KGA RTU in the WOP forum.

[BaldLoonie]

Typical of any gas pack with the heat exchanger in the cold air. We've never lost a Rheem tubular heat exchanger on a gas furnace, 80 or 90, but had to replace one in a gas pack a few years ago. I think York is one of the rare brands who put the HX before the coil. Or if people aren't too cheap, get a model with a SS exchanger.

[slctech]

What I find intriguing is that this customer has a mix of RRGG and RRGF units. All installed the same time maybe a year apart at most as each building of this business complex was erected. I rarely have issues with the RRGF exchangers, it is ALL the RRGG units?
Like I said not saying this is a WOS situation, but maybe you could help me understand the difference between a RRGG and a RRGF heat exchanger. Both model types look exactly the same, same components, same style exchanger, just one seems to crap out and rust all to hell where the RRGF is hanging in there just fine.
I would love to have more failures with the RRGF units....more sales

[John Markl]

These look to be virtually identical to the RUUD rooftop thread I started a few weeks ago here. Stupid design to begin with. How are you supposed to check operation or trouble shoot the heater, with that forced draft blower that becomes useless when you take the cover off?

[BaldLoonie]

Parts list for RRGF says "heat cell coated" and for RRGG says "heat cell" with different part number. Could be the newer model left off the coating for cost reasons and that is causing more failures. Customers want low price not long life.

[slctech]

Thanks Baldie, makes a bit more sense, wonder what type of coating. Must be on the interior of the exchanger since the RRGG is rusting from the inside out.

As for working on the heat package of these old Rheem units, I will admit that if you have the burner compartment panel off and you are doing some troubleshooting, keep your face away....you will get one hell of a roll-out. Much like the Rudd unit John Markl was talking about in his thread.

[John Markl]

As for working on the heat package of these old Rheem units, I will admit that if you have the burner compartment panel off and you are doing some troubleshooting, keep your face away....you will get one hell of a roll-out. Much like the Rudd unit John Markl was talking about in his thread.

You too, eh ?

[snowderandsons]

New parts are available, . . . . I've made a KILLING changing out these HE. Customers are happy because they did not have to foot the bill of an entire new package unit, and I am happy because I made serious dough.

[BaldLoonie]

As for working on the heat package of these old Rheem units, I will admit that if you have the burner compartment panel off and you are doing some troubleshooting, keep your face away....you will get one hell of a roll-out. Much like the Rudd unit John Markl was talking about in his thread.

We seldom work on a RTU or packaged unit but our rookie just happened on a URGF today. And about lost his beard to rollout!

[slctech]

Thanks for the laugh Baldie!! Glad to see that John and I are not the only singed hair guys out there!

[MarkArispe]

Im in California and every time I come in contact with this particular brand of unit I always look for cracks in the HX. I find cracked heat exchanger more common in these units. I know exactly where to look.

[sammy37]

These look to be virtually identical to the RUUD rooftop thread I started a few weeks ago here. Stupid design to begin with. How are you supposed to check operation or trouble shoot the heater, with that forced draft blower that becomes useless when you take the cover off?

Yeah, I never cared for these earlier units. That combustion setup was a joke.

[sammy37]

Typical of any gas pack with the heat exchanger in the cold air. We've never lost a Rheem tubular heat exchanger on a gas furnace, 80 or 90, but had to replace one in a gas pack a few years ago. I think York is one of the rare brands who put the HX before the coil. Or if people aren't too cheap, get a model with a SS exchanger.

These old rheem units had the heat HX before the coil also.