NORCOLD 1200 high altitude burner?

[SCVJeff]

Yeah I know this has been asked before and what NORCOLD recommends above 5000?, but..

Several years ago I bought a spare 1200 burner when mine was acting up and swapped them. From day 1 it has sounded like a jet, probably 6db louder than the OEM with an occasional backfire. I thought that to be debris in the tube but never resolved the reason why.

Today I took my original burner apart as well as the ?jet? and set up a test jig on the bench. I found that the orifaces both perform identically, and that the difference is the burner/ mix tube. Upon further examination I noticed that the Jet has 4 air mix holes, and the OEM has 3, and if I stick my finger and block one of the 4 holes (yes it was hot..), the Jet now looks and sounds exactly like the other one.

I have read and have been told that NORCOLD only makes one burner, but clearly that?s not the case. This WAS the same part# when I bought it but it is NOT the same part

NORCOLD says to use AC on altitudes above 5000?, but what about those sold and starting life in places like SLC, Denver, etc. ?  This HAS to be a high altitude mix tube..  anyone have any intel on this?

 

[Gary RV_Wizard]

I have read and have been told that NORCOLD only makes one burner, but clearly that?s not the case. This WAS the same part# when I bought it but it is NOT the same part

Anybody can slap a part number on. Is the new part from Norcold itself, or a part for a Norcold? Not the same thing...
High altitude needs more air volume to get the required amount of oxygen for a given amount of gas in the burner.  Most of the high altitude kits I've seen change the burner orifice to manage that, but I suppose the tube could be designed to suck more air and mix it in the right air/fuel ratio.  I'm not expert enough to say whether the tube you have could do that or not. Number of holes doesn't necessarily correlate to air flow, but other things being equal, wouldn't fewer holes reduce air rather than increase it?  The jet noise you hear indicates air is flowing faster to make up for the reduced opening.

 

[SCVJeff]

This was a NORCOLD part in a NORCOLD bag with the NORCOLD burner part number on it. I?ve never seen anything other than the control board for that fridge built by someone else. (Not yelling NORCOLD. That?s my spell checker). This was bought at Neil?s RV in Van Nuys, CA.  One of the bigger places in the area

The Orafice?s are exactly the same. Under a PC board inspection microscope, holes are identical: rectangular punched. And Yes, that extra hole allowing 25% more are in IS what?s causeing the noise, to the point of almost blowing it out. The is one of theirs.

Guess I?ll call the factory tomorrow and ask them about this and see what the story is

 

[Gary RV_Wizard]

Sounds to me like they just cost-reduced the part.  One less hole to punch probably speeds up the assembly line and the the reduction in capability is just noise that the owner has to bear rather than the engineers.

I wonder if Norcold may have sourced the part from a different supplier than years back. That sort of thing happens when a new supplier comes onboard and says he can meet specs at x% less cost by this one little change...  Maybe somebody here with a later year (post 2006) Norcold could check the air holes on their burner tube.

 

[SCVJeff]

It?s reverse.. the original part was the one that ?worked?. The new one has the 4th hole

 

[Gary RV_Wizard]

I re-read the opening message and see I got it backwards.  Sorry if I confused things...

 

[SCVJeff]

Strange Eh?
If I close off one hole i now have two that work identically. Note sent a note to NORCOLD last night so it?ll be interesting what comes back.  I was always told there is only one burner/mix tube for these things but that?s clearly not the case

 

[Gary RV_Wizard]

I still think what you are seeing is a simple case of a new version of the same single part.  It's the same part number, not a different part for different altitudes.

 

[SCVJeff]

Maybe so, but I have compared this assy. up against several other 1200?s, and we all agree this one is considerably noisier than anything else we all listen to, probably 6db, and thats a LOT. Quartzsite is very quiet to make these comparisons, and theres a bunch of 1200?s everywhere to compare. Only this ONE burner is different. Also as mentioned, this one occasionally backfires (pops). I can immediately fix that by covering a single hole.
Waiting for a response from the factory too.

 

[Sharshep]

EtAl
Yep I am having the same issue this year.  But my unit is ten years old and I have been following the same route for all that time. Has the orafice corroded? My ignighter is 3/8 above the furthest grove. (As recommended by Bozeman MT RV tech). I understand the science but there has to be a manufacturer suggestion for a fix. My unit works well on ac. I guess replacing board and thermistor per professional mobile RV repair guys was not needed. I went through a bunch of ice but I am not willing to accept a non working unit.
Thanks everyone.

 

[Primerump]

Maybe so, but I have compared this assy. up against several other 1200’s, and we all agree this one is considerably noisier than anything else we all listen to, probably 6db, and thats a LOT. Quartzsite is very quiet to make these comparisons, and theres a bunch of 1200’s everywhere to compare. Only this ONE burner is different. Also as mentioned, this one occasionally backfires (pops). I can immediately fix that by covering a single hole.
Waiting for a response from the factory too.

The issue is the air to fuel ratio/mix..  like a car, the mix has to be within a certain range for optimum combustion.

what you need is a way to control the air mixture with an adjustable sleeve. it's a pity norcold did not do this with the original design
then it would be a simple matter to adjust.

how about using an old burner, cutting off the burner end to leave the tube with the holes in, then slit this down the middle and expand it a little
so that it can slide over the new burner assembly holes. it should be springy enough to stay in place.
slide or rotate this "sleeve" to restrict the air flow, if you look at the burner flame it should be a nice blue color.
i know it sounds like a hack, but it should work, when you get to sea level then adjust it back..