Natural gas vs Propane - is either better for temperature stability?


 
Long time griller, first time poster. I'm thinking of replacing our 21 year old Genesis Silver B. From lurking on this site, I see that many of you are still keeping these old grills running. But I'm tired of buying replacement parts and I don't know how much longer they will be available.

My main gripe with this old propane grill is that its temperature stability is poor when running at low flame levels. I measure with a digital probe of air temp inside the closed grill. If I am slow cooking ribs, I try to run at about 275F. But the temp can drift as much as 100 degrees higher or lower, unless I make frequent tweaks to the knobs. This gets tiresome over a 3 hour cook. I tried various combinations of burners turned off, different settings on the burners, etc.

Are the newer gas grills better for stability? I know that some smokers and pellet grills have features that can regulate temperature. You'd think that, in the 21st century, the gas grill manufacturers would have figured it out.

We have an existing natural gas pipe to our deck, but capped off and never used since we bought this home. So we could use propane or natural gas for the new grill. Is there any difference between NG and propane grills for temperature stability?

Currently leaning toward the Genesis II SE-330 (NG, open cart), SE-335 (NG, doors), or the S-345 (LP, doors, Costco). I don't care about the difference in appearance, and I doubt that we would use a closed cart for storing stuff. Does a closed cart give any functional cooking benefits? Reduced wind effects, fewer burner blowouts? Temp stability?

Weber recommends that the 300 series NG grills should run on 7" WC pressure. How critical is this?
 

Bruce

TVWBB 1-Star Olympian
I have a Genesis 1000 (1993) and I can dial in a temp and it will hold for a long time unless it is really windy outside or the meat I am cooking is causing a flare up. I don't know if the newer grill designs have better protection from wind, but if not, I really don't feel they will function any better....and forget about using a rotisserie on them with the N/S burners.
I have a quality set of Solid rod SS grates and SS flavorizer bars on it and don't plan to have to replace those for many many years. I have about $200 in this grill and I have done almost every kind of meat in it sans lamb. I have done brisket, ribs, turkey, hams and various steaks and roasts, not to mention dogs and brats and sausages. I have done various vegetables and even pizza, all with great results. I live in Wisconsin so temp variations are expected, and I use a remote thermometer like you to monitor interior temps. I can get the temps dialed in and not have to worry about it on a long slow cook such as ribs or brisket for over an hour at a time while the temp is held within a range of 20 degrees the whole time.

Clean up the Silver B, get yourself some good 9mm SS solid rod grates, some good 16 gauge SS flavorizer bars and a new set of burners. You can get them all for under $20 and you will have a good, low maintenance well performing grill for another 20 years. Take the extra $600 - $700 in savings and buy a half of a cow.

Just my opinion.
 

J Grotz

TVWBB Wizard
You'd think that, in the 21st century, the gas grill manufacturers would have figured it out.
You'd think, but no. And Weber even introduced new "Smart" gas grills recently that don't have this feature.

So we could use propane or natural gas for the new grill. Is there any difference between NG and propane grills for temperature stability?
Weber designs different manifolds and valves for its LP and NG grills, and it does not sell conversion kits. You can't simply swap out some orifices on a Weber to switch fuels. So at least on a Weber, there should be no difference in performance. But be sure you purchase the correct grill for the fuel you decide to use because there is no going back.

I restored a 1995 Genesis 1000 LP a year ago, thanks to the helpful folks around here like Bruce. My 1000 holds its temps no matter what the wind does (Santa Anas), but living in SoCal I don't see much severe weather. I use it for weeknight cooks and rotisserie work. I have also cooked on a NG Summit in the wind and had the same experience.

Restoring your Silver B is a great option, but sometimes you're just tired of something and want a new one; it happens to me all the time.

Currently leaning toward the Genesis II SE-330 (NG, open cart), SE-335 (NG, doors), or the S-345 (LP, doors, Costco). I don't care about the difference in appearance, and I doubt that we would use a closed cart for storing stuff. Does a closed cart give any functional cooking benefits? Reduced wind effects, fewer burner blowouts? Temp stability?
My 1000 is an open cart and has never had a problem no matter what the Santa Anas do. In fact if the wind is blowing, I'm more likely to use it than one of my charcoal grills. Closed cart Webers seem more prone to rust than open cart models. Since you are not going to use the cabinet for storage, I recommend an open cart. I love the SE-330 LP in Crimson. It's a gorgeous grill with some nice value upgrades. Purchasing those 9mm grates aftermarket more than makes up the difference between the E and the SE, iirc. The new Genesis IIs you are considering do require you to keep up on maintenance. There's a thread here about a guy in Florida that flips them and thinks they're crap, mostly because of the little pieces in the firebox that hold the burner tubes in place. It seems like most of the grills he acquires have been seriously neglected and abused. So keep it clean and keep it dry (as much as you can in the PNW) and you'll have a great grill for many years.
 

LMichaels

TVWBB Olympian
Temp stability is a function of a number of different things. First, wind (and temp) basically ambient conditions. No grill will hold a steady temp if it's in a wind tunnel. Combine that tunnel with cold temps and even worse.
Next, would be condition of the grill itself. How well are the burners functioning? Are they clogged? What about the gas delivery (not type of gas delivery of gas)? Is the manifold operating correctly, has someone played with the air shutters, are the orifices (internal and external) of the valves clean and functioning properly.
Finally is "mass". If you have thin flimsy components in the grill temps will not be steady.
Gas type is NOT an issue. A NG grill will not behave differently than LP EXCEPT when that LP tank is subjected to very cold temps (here NG is superior), or the tank is nearly empty and cannot hold proper pressure to the regulator.
Next I REALLY have to question what parts are you "constantly buying"?! If you bought/buy GOOD parts to begin with (flavorizer bars, burners, and grates) they should be nearly lifetime investments. Get some REALLY good HEAVY stainless grates (don't fall for the gimmicky stuff). Get some from RCPlanebuyer. While you're at it get some flavorizer bars from him as well. I guarantee these will be the last "parts" you ever have to buy. If you can find them get some OEM burners. IMO these are still the best bet rather than aftermarket. They're heavier gauge and better material.
Now turn your attention to the manifold. Look for the video Chris A was kind enough to put together explaining how to clean and lube the valves and last remove the external orifices (the little jets on the outside of the valves) and clean them. They build up some corrosion and debris and can/will cause MANY issues.
Now once all this is done you will have a grill that with a little cleaning will be a tool you can depend on to do the job.
Now on to gas type. When stoichiometric settings are correct (proper amounts of gas and pressure) to air neither will perform better/worse than the other.
If you can put your hands on a NG manifold set for your grill I would HIGHLY recommend NG just for convenience sake alone. Such a joy to not have to run to LP filler.
If you have a GOOD knowledge of gas(es) and how they work along with pressures and know how to work with tools like a manometer, understand the relationship of pressure to flow and so on converting a grill PROPERLY from LP to NG is possible. But, not for the faint of heart or with no understanding of the principles I mentioned
Buy a new grill? Eh, if a new grill is what you want (and it seems you're trying to talk yourself into it) and you have $1200 burning a hole in your pocket..........................sure. Buy a new grill. Me? I would not.
 

G Schafer

TVWBB Super Fan
Lots of good advice given.
Don't forget the thermometer in the lid is not showing the temp at the grates. Get good grates with enough mass, and flavorizor bars with enough mass. Those won't change temp quickly when the wind blows and will hold the heat by the food.

Edit to add: my grills are a bit older than yours, at about 35 years old and I wouldn't trade them for what's on the market now!
Edit again:. I see you are using an internal thermometer. It will probably fluctuate with the wind a lot too. You might try some form of wind break, or try turning the grill 90 or 180 degrees and see if it helps. I find that I get fluctuation of lid thermometer temp when the wind is blowing in from the manifold side. Try facing the lid into the wind and see if it helps.

Gerry
 
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GrantT

TVWBB Member
Perhaps newer ones are better (as I have not had a gasser in many years), but I always found natural gas BBQ's to be anemic compared to their propane cousins.

That said, I have a gas line on my deck, so having the convenience (and lower operating cost) of NG is a big plus as long as the BTU's are there. Having a camper, I always have a couple LP tanks around and my only BBQ is a portable cheapo for when the fire burning bans kick in.

One downside to NG is portability...if you ever want to move it....
 

LMichaels

TVWBB Olympian
but I always found natural gas BBQ's to be anemic compared to their propane cousins.
That will only happen if it's not built or converted correctly. If it's jetted correctly and the line can carry proper pressure and volume than it's no different. Sadly there are all kind of hacks out there, doing plumbing incorrectly, reworking grills incorrectly and it's not only poor performance it can be very dangerous.
 

Bruce

TVWBB 1-Star Olympian
Yah, I have no real experience running grills on NG, but I do believe they are rated for the same BTU's on both.
 

G Schafer

TVWBB Super Fan
The older Weber grills that I am familiar with (and I'm sure this goes for the ones I'm not familiar with) had the same btu rating whether lp or ng from the factory.
 

GrantT

TVWBB Member
I had a factory configured Weber Genesis Silver C (natural gas) - three burner (this was about 12 years ago) and it was very slow to heat up and sear etc. Could have just been the model etc...but compared to ANY propane BBQ I have ever tried...it was weak. Good to know they do perform roughly the same....I'll take your collective experience for it!
 
Thanks to everyone for the tips and suggestions. Still mulling over whether to keep rebuilding the old LP Weber or replace it. But, because we have an existing and unused NG pipe on our deck, that's an attractive option. I'm not keen on the idea of trying to do a fuel conversion on the old grill. I have experience in modding electronics and software, but hacking a gas appliance involves a bit more risk. So if we go NG, a new grill is in order.

But before that, I want to make sure that this pipe is actually functional, connected to the house gas supply, and with enough pressure.

My struggles with temperature variations may be related to wind conditions, as several of you commented. Our grill is standing on an exposed second story deck, and I sometimes run it in windy or rainy weather. Welcome to the Pacific North-Wet.
 

LMichaels

TVWBB Olympian
Before you drop a ton of coin on a new one throw a trade out there for your manifold for a NG one. Easy PZ swap. You will still have a superior grill to the new ones. You'll want to make sure you have at least 1/2" pipe and that it's at least that big all the way back to the main supply. As long as everything else on that supply runs OK you can be pretty assured that stub is supplied well. In the world of black iron gas pipe a 1/2" pipe is about 3/4" outside diameter. If you see 1/2" OD don't bother as that is only 3/8" pipe and will not give a good supply to a grill going full tilt or keep up even operating pressures.
 

Bruce

TVWBB 1-Star Olympian
Yep, the conversion is not complicated if you swap the manifold. You cannot find them new any longer, but they are out there and available used. So, the option of rehabbing the old grill is still out there.
But, you have to do what you feel best with. If you have the money and want a Genesis II, I am sure you will like it. We just want you to be informed in making your decision. Either way, keep us posted and drop some pictures.
 

Sam Bee

TVWBB All-Star
Julian, I live in the Pacific Northwet (west) as well, although today wasn't a bad day (2/24, sunny, mid 40s). Whereabouts are you? I might have a Silver B NG manifold I could part with if you're looking to swap it.
 

Rich Dahl

TVWBB 1-Star Olympian
I have a NG and a LP early sidewinder models of the genesis. Virtually no difference in stability or output. Really the only difference is the NG bottle never runs out of gas. 🙃
I have a set of RCPlanebuyers SS flavorizer bars that are about 10 years old and still like new, they are the best of the best.
 
This weekend, I did some clean-up work on the Genesis Silver B. After a couple of hours of scraping (while trying to ignore spikes of lower back pain), I decided that I'm just not motivated for a refurb project on this thing. At this stage of my life, I would rather do my refurbs on vintage hi-fi gear.

So I put the grill up for sale in the Buy-Sell-Trade forum. If any of you are in the PacNW and looking for grills to refurb and flip, give my ad a look, or send me a PM. I'm including an unused rotisserie attachment, an extra piezo igniter, and a tank.
 

Bruce

TVWBB 1-Star Olympian
Julian: I understand that. I used to be a big DIY guy. If I could I would always do the work myself, even it if was probably more prudent in the long run to have it done or just buy new. I like you have lower back problems and sometimes get part way into a project and start regretting it. I know I won't be doing grill rehabs for ever and will have to give that up at some point. But, I will make sure, before that point comes, I have a nice old classic Genesis to last me to the end of my days before that point comes.

So, if you grab a new Genesis II, post up some photos and give us your thoughts on how it works out for you.
 

J Grotz

TVWBB Wizard
I saw your ad, that's a great price. Good luck with your purchase. And like Bruce said, post up some photos and thoughts of what you get.
 

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