Continuously Variable vs. Low Medium High


 

THyde

TVWBB Guru
I just re greased my valves. How do you know if you have “continuously variable” vs. three position valves?

The valves have 3 holes on the cone part, but when I was putting the grill back together I was looking at the flames and they do seem to adjust between the different settings.

How can you tell what type you have?

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PS: freshly re-lubricated valves are GREAT!!
 
I assume its a 1000 by your pic those are fixed not variable yes they have 3 holes different diameters and yes i have done two sets for .99 probably could do 20 sets but makes a big difference.
 
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Yes, it's a Genesis 3000 that I converted to a natural gas 2000. So why do the flames appear to change in size between the settings? For example, if I go from "High" to between "High" and "Medium" it appears the flames lower by about half. I don't get it!
 
I have a genesis 1000 too and I always thought the valves were continuously adjustable? They seem to be even though there are clear high, medium, and low markings. I could be wrong though.
 
I think they are variable, just have the markings so you know where the adjustment is at. I have a Genny 1000 and I know it is variable. I can tweek my grill by just a few degrees by moving the knobs. When doing long BBQ's and slow cooks, this is critical. I can adjust my grill to any temp between about 200 and 600 and have it stay within a +/- ten degree window. I measure this with my Smoke remote thermometer which is very accurate.
 
So the Low Medium High is just settings on the valves? Like, "seating" in the spots for those settings?

I'm now really curious. I think you can adjust between settings too, but I am eagerly anticipating some expert input (read: LMichaels)

Slainte!

Tim
 
There were no photos BUT if your cone has 3 "openings" and distinct "click" spots it's a fixed orifice. The variable valve cones have "slots" or "grooves" rather than "holes" and have no distinct "click" spot other than fully "off" as for varying in between holes yes of course it will as if the orifice moves off center it's just like if you put your finger over the end of the water hose. You change the flow due to the "hole" or the opening being obstructed
 
There were no photos BUT if your cone has 3 "openings" and distinct "click" spots it's a fixed orifice. The variable valve cones have "slots" or "grooves" rather than "holes" and have no distinct "click" spot other than fully "off" as for varying in between holes yes of course it will as if the orifice moves off center it's just like if you put your finger over the end of the water hose. You change the flow due to the "hole" or the opening being obstructed

This makes perfect sense. Thank you!
 
My Weber LP Summit, purchased new in the July 2010 timeframe, has 3 holes in the valves, but the upper one has a groove over it (to the left and right of it), and there are no distinct clicks at low, medium and high settings.

So are these “fixed” or “continuously variable”? I’m attempting a conversion to NG, so I would really like to know how these valves are classified.
 
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That is a fixed orifice type. The ones that are variable have a slot all the way around. I have only seen them once. On my brother's Summit Silver never anywhere else. And his took to NG conversion like a duck to water. All I did was put in properly sized orifices and it works like a champ
 
Wonderful, so I may need to drill out some of the holes on these valves. I assume the safe bet is to see how it performs before doing any surgery, correct?
 
It's what I do. I haven't done one in a while and I lost the information I wrote down. I actually had written down the drill sizes needed for the low/med ports just slappin myself otherwise I could help you better. Sometimes if you size the main orifice for full 7" line pressure you only really need to open the low port
 
My main orifices were sized for a 5” WC regulator. I would think smaller WC sizing would result in larger orifice holes, so I think I’m better off with them being sized to 5” WC as opposed to 7” WC?
 
All you can do it give it a go and see what happens. I have not had one work properly after conversion on low but on medium it's been pretty close. The issue is that if you resize low to work correctly and leave the med setting alone there is little to no difference in output from med to low. Again I am sorry I did not keep better track of the correct sizes. In my scattered world s^&t gets lost LOL
 
I’ll let you know how it goes. One additional question. Did you try to adjust the “carburation” (air damper) on the units that you could not get to work right?
 
No there is no need to ever touch those. Once the gas is regulated and metered properly they should not vary from factory unless you take the grill to extremely high altitude. Gas is gas as far as the burner is concerned. All the "magic" happens prior to the burner
 
Well, I fired it up.

All the burners seem to have good flame heights on medium and high but they do have low flame heights on the low settings. I can't get any to snuff out, but the flame heights are like 1/4". I have a brand new natural gas S-670 here as well (long story) and on the low setting the flame heights on that unit are about twice as high (1/2" or more). I hate to say it, but I think I can objectively confirm that the issue with the fixed valves is not subjective, I’m side by side with a new S-670 NG and the converted LP S-670 has half the flame height on the low settings.

Strange that this is not a more well known issue, grill-repair.com, where most folks get their parts and orifices, scoffed at the notion when I mentioned it to their resident expert on conversions.

No matter what I do I can’t get the flames to snuff out, so I don’t see this as a safety issue, but it does compromise the grill’s usefulness. I may try to drill out the small hole on the valves. The medium holes (at least on mine) do not appear to be conducive to drilling out, and the flame heights on the medium settings seem fine.

Thanks for all the info!
 

 

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