Harman P52i Cast Iron Corrosion

[offtrac]

Good morning,

I am looking for some insight on my 18 month old P52i that is “eating” up cast iron parts inside. Specifically the medallion and heat exchanger plates keep corroding/delaminating. See attached pictures.

The first time I noticed was after the first season of burning (last year.) I was having it serviced and was asking the technician why the plates were discolored. He should be it wasn’t just color and that the metal was flaking off.

Harman replaced all three parts prior to the start of this season and now only a couple months into this season, all three parts have the same defect. Both the dealer and technicians claim they have never seen this before. Harmans answer is to install outside air and scrap the burn pot every day. The stove already has outside air installed and if not scrapping the burn pot everyday is the cause, this would be a widespread problem.

Let me know what you think!

Thanks in advance...

Sent from my iPhone using Tapatalk

 

[rickwai]

Bad castings. I have seen the same thing on a 52i. Harman replaced them at no charge

 

[offtrac]

Bad castings. I have seen the same thing on a 52i. Harman replaced them at no charge

Two sets though? They already replaced them once and the second set (pictured) has the same defect.


Sent from my iPhone using Tapatalk

 

[Harman Fifty Two i]

My stove is three years old and looks exactly the same as yours. I have outside air kit too and scrape the burn pot faithfully and keep the stove clean in general. I’ll have to ask my dealer if they’d be willing to replace mine. I’ve been thinking of getting some black stove paint over the summer and painting them. To answer your question though could it possibly be moisture some how coming in from the outside air kit?

 

[offtrac]

My stove is three years old and looks exactly the same as yours. I have outside air kit too and scrape the burn pot faithfully and keep the stove clean in general. I’ll have to ask my dealer if they’d be willing to replace mine. I’ve been thinking of getting some black stove paint over the summer and painting them. To answer your question though could it possibly be moisture some how coming in from the outside air kit?

If your plates look like that they should replace them but it sounds like you are outside warranty. According to the dealer this is not normal.

My outside air kit extends part way up a 30 foot chimney. If moisture was being sucked in I’d think it would be instantly vaporized with the stove running.


Sent from my iPhone using Tapatalk

 

[Cody901]

Mine will get the rust color but no flaking. I wire brush them every two weeks when I’m doing a full cleaning. I will definitely keep a eye on mine now.


Sent from my iPhone using Tapatalk

 

[offtrac]

Mine will get the rust color but no flaking. I wire brush them every two weeks when I’m doing a full cleaning. I will definitely keep a eye on mine now.


Sent from my iPhone using Tapatalk

Interesting thanks for the feedback!

If it was just color I wouldn’t care but the flaking is unacceptable!


Sent from my iPhone using Tapatalk

 

[Ssyko]

You could have them sandblasted and ceramic coated (powder painted) some blacks can withstand 800f. As long as its not in the burn pot im thinking it would work and look nice too.

 

[Cody901]

Interesting thanks for the feedback!

If it was just color I wouldn’t care but the flaking is unacceptable!


Sent from my iPhone using Tapatalk

Yes I agree! They should replace them again and hopefully you’ll get lucky.


Sent from my iPhone using Tapatalk

 

[Ssyko]

you could also clean with a wire brush and then coat with olive oil and bake for half hour that will season them like a skillet. They never rust

 

[offtrac]

you could also clean with a wire brush and then coat with olive oil and bake for half hour that will season them like a skillet. They never rust

Both good ideas. I know a powder coat guy. Might have to resort to that if harman doesn’t rectify before warranty runs out or if they admit they have a shotty casting process.


Sent from my iPhone using Tapatalk

 

[offtrac]

One of the bothersome issues with this is instead of saying “you have a bad cast” they are trying to say it’s a stove issue and if it’s a stove issue I think they should fix the stove and not keep replacing the plates...


Sent from my iPhone using Tapatalk

 

[greg13]

By looking at the pitting in the first two pictures, I would say they got a batch of poorly cast metal.

 

[Ssyko]

How thick are theses pieces that are corroded?

 

[offtrac]

How thick are theses pieces that are corroded?

I’d say about 3/8”


Sent from my iPhone using Tapatalk

 

[Paulinator]

My center medallion also has that orange color. No corrosion though, and I clean them with my ash vacuum during my monthly deep clean. My stove is 1 1/2 years old. I burn Douglas Fir pellets only. There is no orange discoloration on the side plates. I will be keeping an eye on them.

 

[Ssyko]

I understand you don’t want to look at the corrosion or degradations of the panels, but 3/8 thick would take 20 years to blow through. Get new ones and coat them or season them. Inside that fire chamber is some pretty rude conditions. Moisture in the air will corrode or rust no matter what you do. This more than likely starts in the summer and when you fire it up for the season it drys it out and what is left is the flaking. My quad was in my shop for the better part of its life and the cast pot is pitted from all the years of abuse.

 

[zrock]

what are you burning?

 

[offtrac]

what are you burning?

This year I have Vermont, Logik, Northern Warmth Pine and Douglas Fir and Patriots.

Last year it was exclusively Okanagan Golds.


Sent from my iPhone using Tapatalk

 

[fmsm]

Both good ideas. I know a powder coat guy. Might have to resort to that if harman doesn’t rectify before warranty runs out or if they admit they have a shotty casting process.


Sent from my iPhone using Tapatalk

Not being a wise guy and I truly don’t know the answer but would the powder coat inhibit the heat transfer? Even caked on ash insulates and degrades performance.

 

[rickwai]

It is a bad metal/casting issue. I have been servicing Harman stoves for 12 yrs. and just the past couple of years have I seen the cast parts burning out in 1-2 yrs. The older Accentra inserts have similar castings and regardless of how the stove is cared for, they are still like new. Since HHT took over things have changed. It seems like they are still using the good iron for the flame guides and trying to cheapen up on the casting that are not in the direct line of fire. It is definitely 2 different alloys. The most I have seen in a neglected stove (older units) is very light surface rust on castings, typically they are rust free. Normally the stove has laid full of ashes all summer when I get there to do the annual cleaning.

 

[Ssyko]

Not being a wise guy and I truly don’t know the answer but would the powder coat inhibit the heat transfer? Even caked on ash insulates and degrades performance.

Yes fmsm it would affect the heat tranfer to a degree but i would think it would be minimal. The ceramic coating would be smoother than the cast surface and may help keeping the ash from building. It is an experiment i will have to try when i can get through the 7 foot of snow that covers my paint oven

 

[GeHmTS]

Ordering another one will probably yield the same result again. Protecting them with some kind of refractory coating sounds reasonable as long as it can withstand the temperature. Is the medallion and heat exchanger connected to a common metal?

The discoloration on the heat exchanger is a clue as it appears on the left side of the image that you're holding in your hand. The medallion seems to have a more random discoloration. Corrosion is a difficult one to solve, but not impossible.