Need sealant on gas cooktop tube fittings?

Sukhoi

Elite Member
Dec 5, 1999
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I need to replace the set of tubes to the center burner in my gas cooktop after breaking off the orifice trying to clean it to stop the burner from sooting, then breaking the orifice holder trying to remove the broken orifice. Do I need to use any sealant either on the mating surface or the threads when I install this new part? I'm not familiar with that fitting type. I have RectorSeal 5 around. I'm also assuming the torque on these is going to be very low. Pics of the new part attached. Thanks!

Oh and is there any need to leak check these connections after they're made? It's kind of tricky to do with an open ended tube.
 

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Last edited:
Nov 17, 2019
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You shouldn't need goop for those. Do the old ones show any sign of it? Might be best to check with the appliance manufacturer or where you got the parts to be sure.
 

Sukhoi

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Dec 5, 1999
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Not sure yet. I think tomorrow I may try taking it all apart. I'm leaning towards no goop as well. Bosch customer service is absolutely useless, which I will keep in mind when buying future appliances. Took them a week to reply to my message asking for the orifice part number as it isn't on their parts diagram. And of course the reply just gave me a link to the parts diagram. It's been 2-3 weeks since that with no response. I correctly determined that since each tube has a different part number the orifices must ship with the tubes.
 

Sukhoi

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Dec 5, 1999
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Oooh finally found a video showing disassembly of a similar cooktop.
Confirms the top shouldn't be weight-bearing (I can't easily get below it as there's a built-in oven), and no sealant used on the aluminum tubes. Ah and this one which is nearly the same model and confirms the non-load-bearing top
 

herm0016

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Feb 26, 2005
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compression fittings require no sealant.

you only need sealant if the threads are the thing sealing, these have a tapered seat that seals with the cone shape.
 

Sukhoi

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Dec 5, 1999
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Yeah at first I didn't understand it was a compression fitting. I'm used to a much more precisely machined mating surface. 🤣 That made me question if this was some weird fitting that did need sealant on the mating surface. I think I'm going to get around to doing this job tomorrow so hopefully it'll only take me 20 mins. I already checked and the rest of the burner screws are not seized so the top should come right off.
 

Sukhoi

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Dec 5, 1999
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Everyone at Bosch involved in the design of this cooktop should be executed. I've never worked on something so unnecessarily difficult. There's a shit ton of room in the box under the top but it's designed like it's the engine bay of a race car, and not in a way that has any apparent cost savings. It's to the point that there are stamp cut holes in the sheet metal frame that holds the orifice holders, and the holes are oddly shaped with useless material that makes it a contortionist act to try to get the holder & tubes part through the hole and into place. Just cut them bigger; it doesn't cost more and in fact you can save money by recycling more scrap! Then on the valve end there isn't enough vertical room to get the tubes out, but the valve has a concave side to fit around the main gas manifold so if you raise the valve at all to make room for the tubes under it the manifold curve forces the valve farther away, and that god damned hole in the sheet metal isn't cut large enough to let the orifice holder move with the tubes so you can attach the tubes to the valve. I finally barely wiggled things together but just replacing one set of tubes took me hours and an absurd amount of disassembly. Their customer service is also the worst I can ever remember encountering.

/rant
 
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Torn Mind

Lifer
Nov 25, 2012
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Everyone at Bosch involved in the design of this cooktop should be executed. I've never worked on something so unnecessarily difficult. There's a shit ton of room in the box under the top but it's designed like it's the engine bay of a race car, and not in a way that has any apparent cost savings. It's to the point that there are stamp cut holes in the sheet metal frame that holds the orifice holders, and the holes are oddly shaped with useless material that makes it a contortionist act to try to get the holder & tubes part through the hole and into place. Just cut them bigger; it doesn't cost more and in fact you can save money by recycling more scrap! Then on the valve end there isn't enough vertical room to get the tubes out, but the valve has a concave side to fit around the main gas manifold so if you raise the valve at all to make room for the tubes under it the manifold curve forces the valve farther away, and that god damned hole in the sheet metal isn't cut large enough to let the orifice holder move with the tubes so you can attach the tubes to the valve. I finally barely wiggled things together but just replacing one set of tubes took me hours and an absurd amount of disassembly. Their customer service is also the worst I can ever remember encountering.

/rant
Seems like the most German thing to do.

Gotta make a living though, and that means sales, which means obsolescence of durable goods.
 

Sukhoi

Elite Member
Dec 5, 1999
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You're saying it's acceptable to need to replace an entire $1500 cooktop because one tiny little orifice broke off?
 

Torn Mind

Lifer
Nov 25, 2012
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You're saying it's acceptable to need to replace an entire $1500 cooktop because one tiny little orifice broke off?
Not that it is acceptable, but it is how the system operates. Apparently, a similar culture is put into German cars.