I have been jacked around enuff by Bosch & the local absolutely-no-service-dealers.
I have a Bosch NHT 722 A UC stovetop. Two 12,500 BTU burners, two 6,000 BTU.
I need the 4 orifices to switch it to propane. Bosch gave me a part number for a “kit” and told me only through local dealer, no direct sales.
Local dealers are of no help, you can’t get there from here. Or not with these people anyway. Lowes believe it or not did call me back twice, but no help still.
This is not the Mystery of the Universe, but it might as well be. Amerigas tells me they can’t just give me the orifices, unsafe, I’ll kill myself ect.
Can’t find them on the web either.
Who has a dozen in their junk collection, or what do I need to know to obtain them locally?
Joe H
Replies
Who sold you the stovetop? No propane orifices, take it back.
"A job well done is its own reward. Now would you prefer to make the final payment by cash, check or Master Card?"
They don't come with it, gotta buy separate. See local dealer, go in circles, go away.
Joe H
JoeH-You need to check the stove top regulator also.
For Nat. gas the reg. is set for 3.5 / 4.0 inches of water column (W.C.).
With LP the reg. is blocked open to run at 11.0 " WC, which is
what the whole hose reg. is set for.....Frank
Frank, did that when I installed the stove top.
I'm ready to cook, but no orifices.
I am ready to cook, DW slipped in the snow Friday & broke wrist. Stupid woman, now I am the cook.
We're in trouble.
Joe H
Sorry to hear about the slip, You know it was the stove tops fault.
I'm gonna do a little more hunting this am, it's still snowing out? It is March 20th isn't it?
I got to the website with that valve part I showed and it listed the conversion kit Discontinued. I'm gonna look some more.
5600' man are your cooking on top of Everest can't breath must get air oops must get orifice.
Must get more info must get more info, just kidding. Hey a couple of things that you need to find out if you can't get what you need? but I think it would be readily available.
Your location? the elevation above sealevel? What the spec orifice is called for? and the corresponding drill bit.
Maybe with some hunting we can find the info, I'll go hunt with the model# and see if i can find something.
Clay, a man on a mission.
I've been to http://grillparts.com/howto/btu_guide.htm
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These are the existing, the smaller one is marked 119, the larger is 189. They're threaded on the bottom with a tiny ring set into them to keep them from falling out of the socket. Bosch ain't telling what size orifice I need, just a kit they won't sell me direct.
Your picture looks like the burner, as far as I can tell there's no air mixture adjustment, just the orifice.
Elevation here is about 5600' ASL.
Stovetop only, no oven to worry about - got electric for that.
Joe H
Edited 3/19/2006 11:42 pm by JoeH
Trying to figure out the # code of the orifices as you showed 119?=12500 btu at sea level for your appliance.
I know I'm looking at furnace info but it seems more available to figure out. Plus it's all fire to me.
Take a look at these pages, it is getting close.
<!----><!----><!----><!----><!----><!----><!----><!----><!----><!----><!----><!----><!----><!----><!----><!----><!----><!----><!----><!----><!----><!----><!----><!----><!----><!----><!----><!----><!----><!----><!----><!----><!----><!----><!----><!---->http://johnsonsupply.com/york2001/PUB/65075/OUT/N2-1v.pdf<!----><!----><!----><!---->
Clay, bought the stove in CA. That orifice is for NG at sea level for the 12,5000BTU burner.
Joe H
As an experiment say you try and use the orifice that came with it? So what do you get? not enough flame? to much flame much yellow? Turn valve low smaller flame?
It's like a carborator If the jetting is bad it doesn't make the engeng blow up it just makes it choke up or run to lean and burn the valves.
If you look at what I've found so far a sealevel burner would be like a#43 but the same in LP is a 53?55 Now I can't remember what the chart says. But let's say it's a 4 burner 100000btu furnace=Div x4 =25000 btu per burner/valve= twice what we are looking at so in my simple mind I say if one is good then1/2 is ahhhh well 1/2 so that's my thought on the orifice size. Then we have to go to the altitude modification. But I also know that I'd a tried it as it was to see what it's doing AHHH Stand back Idiot with a match.
And as you have found out Bosch wouldn't want you to find out any details of what you have would they.
Clay, with the original orifice the flame is waaaaaaay to big & yellow.
Put the smaller orifice in the larger burner and it is close to right -- small amount of yellow at the ends but a good blue flame. If I have to guess I'd say it's still a hair too big.
Joe H
So what we have to do next is figure out theMM or the hole by using gauging wire or drill bits then step the sizing down a little more, then 1/2 it for the 6000 then match that with a readily available orifice. Hope the wife has a couple of extra pounds cause dinners gonna be a while.
Hmm maybe the new patented JoeH miracle mystery orifice diet.
I also think the coding #s on those orifices are a Bosch #cause it doesn't make sense that a 6500btu difference is a one # difference 119-189
As I read the chart it looks like not adjsusted for alt# 69 drill .0292
5956btu LP @11
and #57 0.043
Btu @11 12916<!----><!----><!---->
And at 6000' I'm gonna down rate 4% per 1000'= 25% so the corrected #s are #62 .038 @10087btu @11" +
#71 .026 @4722 btu @ 11"
Edited 3/20/2006 4:44 pm by ClaysWorld
Edited 3/20/2006 5:32 pm by ClaysWorld
Clay or anybody, what does the proper flame look like?
In the dark I have a light blue flame inner cone with a lavender corona at the outer 1/3. Tiny flicker of yellow occasionally, tiny.
This is with the smaller 6000BTU orifice installed in the 12.5K burner.
Joe H
the flame must be entirely blue. If part of the flame is yellow or orange, the burner must be adjusted;
the base of the flame must be just above the burner at all times;
As I look at the info we have found the smaller 119 orifice fits in-between these 2 sizes on our chart
.0116=93994 BTU at 11
and .12=10588 BTU at 11 so I would think that the altitude adjusted # of 10000 BTU is correct for the large burner.
So how long are you going to be using just 2 burners(Snark)
Now on to find the 4500 BTU orifices
I think I've got one to many 0s in there, have to go back to the first post of the proper sizing, I was trying to figure out why the discrepency with my original sizing post which appears to be correct. not this one. Now the question of why is the small one apear to be working and as shown on the chart as way to many BTUs??????? I'm not afraid to be wrong.
Edited 3/21/2006 11:29 am by ClaysWorld
Blue in color, like Clay said. No yellow tipping, that's a sign it's running rich. Not enough oxygen. Check without the stove grate so the flame does not touch anything.
It should smell clean also. Not raw, if that makes sense.
3" wc, 6k BTU, Nat Gas would be around a number 56 drill. It may be a metric, Bosch ya know.
No 56 drill, 10" wc LP would give you almost 16k btu's.
The burner may, or may not be able to run that high. Sounds like it can but you still need the correct parts to make it right.
Are 3" Nat gas and 10" LP the correct operating pressures? 3" sounds low.
Edited for 10" wc BTU's. And I'd call Bosch back and make them send the correct parts.
Edited 3/21/2006 1:35 pm ET by JAlden
Come on Joe get me something to work with here. Show me a picture of the valve and the # on it.
Orifice size.
The valve orifice fitting is the fitting at the end of the valve which has a small hole drilled into it's center. Most orifice fittings will have their size stamped either on the top or side of the fitting. The orifice size is the actual hole diameter in the orifice fitting. Drill bits although most commonly sold by inch increment size are also available by number. Thus a #56 size orifice is an orifice fitting that has been drilled with a #56 drill bit. Drill bit numbers and sizes have an inverse relationship. The larger the number, the smaller the drill bit. (Orifice hole size will be larger for natural gas supply models than propane because of the lower natural gas operating pressure).
The actual Btu output is determined by the pressure of the gas supplied, volume of gas which is regulated by the valve and by the orifice fitting orifice hole size. As an example, assuming a fixed natural gas pressure of 3.5 inches of water column a #48 orifice will give a different Btu output than a #46. (Altitude also affects the Btu rating.) BTU and Orifice Size Guide
Propane orifices (multiple orifci) are smaller in diameter that natural gas! Just my two cents.
Yup, lots. Molecules are smaller than NG molecules, higher pressure too.
Joe H
So is that make it heavier and as such I'm kind of remembering some places in the news at some point that blew off the map by propane leaks. But then again I remember similar stories about gas leaks that did the same.
Off topic but I've been working on a gopher cure. Maybe doses of LP in the hole will get my cure.
I have been using kerosene and gas mix to much success. All I really wanted were the old M-80s but no can't get them anymore. Oh did I mention Idiot with a match Stand back wayyyyyy back.
Ya but look on the bright side no more gopher holes. Now if I can just get enough fill for that b$mb crater.
Clay, I have an old Remington 514 that cures rabbits.
Probably would work on gophers as well.
Joe H
Kinda evil thought s but it made me feel real good after pouring the gopher cocktail down both ends of his/her/their house hallways and watching that kerosene slow burn. My theory is that is sucks the air out and suffocates em.
Ya I was thinking about cutting off a barrel and taking the shot out and letting it rip,in the hole, yu know SHOCK and aw but then the better part of not in jail in the city got a hold of me. What with homeland insecurity and all.
Light bulb lights up* look for next message
I have a johnstone supply account so I pulled the book out and it's got some of what's needed.
Take a look around at this site.
http://www.andersonforrester.com/
And in my book it's showing LP orifice with a drill size #72 1/4x28 thread of the above brand.
It also is showing Robertshaw Pilot orifice in LP in .011,.01,.016and .088
Joe, here is a copy of a chart with the drill sizes for propane.
Do you know what pressure the stove is operating at? 11" W.C.? If it is different, let me know. Is it regulated at the appliance?
If so, you may be able to redrill the 6k orifices to the 12k size and at least use those two for now.
Sorry for the file size.
J, I think the reg is 10 here, not 11.
There is a reg at the appliance set to 10, I believe the line pressure is also at 10 .
Real dark & cold out there now & wind/snow. Think I'll look at the tank regulator in the light.
Joe H
OK here is the cross reference of drill hole size to orifice size and now your getting real close.
Now we can look at what you have and what you might need and then it can be found.
Here's the same site but the chart specific.
http://www.andersonforrester.com/orifice_capacities/
Actually the propane molecules are bigger than natural gas molecules (methane)ie. Methane CH4 vs. Propane C3H8. It's not the size of the gas molecules that's the problem it's because each molecule of propane has almost twice the chemical energy as methane molecule does. The difference in pressure is also another coplicating issue for the do-it-yourselfer's...bad ideas abound.
Bigger or smaller, the hole's too big and Bosch wants it a secret.
The mystery number on the original orifice means nothing to anyone, or no local source.
May have to cook with the 2 larger burners until I figure this out, but better than no cook at all I guess.
I'd rather not DIY this, but seems to be the only way out for now.
Joe H
Still hunting, only cause it's snowing out.
More reading. http://www.premierrange.com/faq-rangeconversion.htm
some orfices are universal in that they can be adjusted for either nat gas or lpg
those ones have a point behind the nozzle in the centre which restricts the flow if the orfice is adjusted in or increases flow if adjusted out
on the fixed size orfice if we couldent get replacements we would remove the orfice & using a small ballpeen hammer peen the hole smaller then knowing the btu rating of the burner drill the hole to the size in the chart
i used to be liscened in natural & propane and still have the propane hole size chart , their should be a slight yellow on the flame when mix is correct
I'm thinking I'm getting closer so see what you think. NHT 722 A UC
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One of the reasons that they want you to purchase from a dealer is that they also want them installed by a "cert" person because it usually isn't just switching just the orifices, there are adjustments that must be made to the output for your range settings. Oven needs a change over too, if there is one.
I'm suprised that Amerigas won't do it for you. I know that Ferrell Gas will
Edited 3/19/2006 8:43 pm by migraine
I've put a couple of furnaces in in SLC,Ut and we have to change out the orifices so at one point I had???????brain no longer working must eat some more lead paint chips oh- a altitude chard and oriface for altitude. But were getting close.
Check this out.
http://www.alpinehomeair.com/viewproduct.cfm/productID/453055796/p/Goodman_LPT_00A
And then we know we can find it. The propane conversion is some where we just have to find it.
Hmmm I wonder what's in these bags?
Find or figure out the right size, solder up the ones you have, drill them out the right size and your'e done...(old trick when cars had carbs)
Bud