1999 Harman Advance - Flame Lapping brick Backing creating Black Burn Spot!

[Don2222]

Hello

Going through this Harman with a fine tooth comb. I replaced the circuit board with a new one so it works like the new stoves. However I found a long standing issue on the older Harmans where I have not seen an explanation and the sure fix.
The flames were hitting the brick backing and creating a big round black charcoal spot on the back of the iron brick backing!
Thanks to this thread I had a very good clue!
https://www.hearth.com/talk/threads/harman-advance-flame-guide-design-change.83130/

I removed the old Flame Guide and it did not have the air port notches. The flames did not blow out away from the back firewall.

I had a new flame guide with the notches and put it in the stove and TaDah!

The flames no longer hit the back and it works fine.

It is possible that putting in the new circuit board made this problem more apparent, but that certainly explains why the air ports were added!

The Advance and Acentra has the notches because the fire is close to the back. The P-Series does not have or need these air ports!

Pic 1 - Large Fire hitting back
Pic 2 - Small fire shows black back
Pic 3 - Black back no fire
Pic 4 - New Harman Flame Guide
Pic 5 - Old Harman Flame Guide Bottom Vs New Harman Flame Guide Bottom
Pic 6 - Old Harman Flame Guide Top Vs New Harman Flame Guide Top
Pic 7 - New Flame Guide Vs Old Flame Guide
Pic 8 - Flame with New Flame Guide not hitting back and working fine!

 

[smwilliamson]

the accentra has primary air that feeds in throught the burnpot gasket and over the fire. That's why the round lips are on that flame guide. The advance does not have this system. The advance has a rounded flame guide and all other stove do not. Or at least not as rounded. I was told that the advance had a new flame guide made more it because there was turbulence in the stove that caused it to rattle. every advance I've seen has the flame hitting the brick panel. Are you using a single or double impeller fan. The advance doesn't like the twin paddle and the interior will get sooty.

 

[Don2222]

Hello

The burnpot gasket does not feed primary air! The white Lytherm Gasket is just a flat piece of gasket!

Since I was still having trouble with the 1999 Harman Advance, I had to roll up my sleeves. Sometimes we are too quick to jump to conclusions, so this is what I found.

Harman standardize the P43, Accentra Insert, XXV and Advance Burnpots (All 50k BTU stoves) in 2004 (Hard to verify this year exactly but if the stove has the original flame guide it does not have the air ports) according to my very experienced Harman Dealer with the Fluted Air channel in the back of the burnpot to keep the flame away from the brick backing! This fluted channel brings fresh air up from the air intake at the bottom of the burnpot up to the two corner ports in the flame guide to push the flame forward to keep it from hitting the back brick panel and it works! Any stove before 2004 can really benefit from this update!
The new burnpot also has a different hole pattern for a more powerful concentrated flame!
Here is the burnpot in question!
P43, XXV, Advance & Accentra Insert Burn Pot Weldment
Harman P43, XXV, Advance & Accentra Insert Burn Pot Weldment - 1-10-00675

See pics of my 1999 Advance burnpot vs the new Harman Fluted Burnpot. The flame is whistling Dixie now! LOL

Pic 1 - old hole pattern left, see only 4 holes in the back row of the old pot.
Pic 2 - see fluted air channel in the new burnpot on the back plane.
Pic 3 - New burn pot installed
Pic 4 - Small flame going up straight
Pic 5 - Large Flame going up straight
Pic 6 - Low flame where you can see air ports keeping flame away from the back!

 

[smwilliamson]

That's what I was saying.The gasket it channeled out to allow for primary air to come in over the top of the flame. Older advances have the pot like the p series without this air flow. Burnpot has to have the arc cut out too one the back side. This whole burnpot was designed to keep the compass on the accentra FS from over firing and was the first stove to have this design

 

[Don2222]

Luckily, I put a new igniter I had in stock into the new burn pot. The old igniter had bare wire exposed near the end clip! Looks like original igniter since all the old black wire tires were on it! See pic.

So I ran the stove a bit last night in my new workshop. Getting chilly now since there is no insulation yet! LOL
The stove ran great, the additional air holes in the new pot make for a stronger flame and the 2 top air ports really push the flame out!

 

[Don2222]

Burnpot has to have the arc cut out too one the back side. This whole burnpot was designed to on the accentra FS from over firing and was the first stove to have this design

The Accentra Insert, I found has the notches in the flame guide and the fluted burn pot design which is the same as the Advance, P43 and XXV

I do not see any evidence that the Accentra FS has this new fluted design.
This link show the Accentra FS flame guide that does not have the notches which is the same as the P61 or P61a as I stated above.
http://www.stove-parts-unlimited.com/mobile/Product.aspx?id=39131

Yesterday, I worked on a 2009 Accentra FS and it also did not have the notched flame guide and fluted burn pot.

 

[smwilliamson]

I meant to say insert my bad