Weber CEP-310 conversion to NG - heats too quickly


 

DSellors

New member
This is my first post here. Sorry for this lengthy post, but I want to provide as much info/background as possible to get your advice. This is my NG conversion set up, I've attached two pics below to show the installation:

1. New factory sealed Weber NG manifold p/n 67610
2. New Maxitrol regulator p/n RV47L with ½” NPT connections (0.5 psig, Po 4.0”-8.0”)
3. New MB Sturgis NG/LP 10 ft. 3/8” ID gas hose p/n DG-3874
4. 3 new brass fittings/adapters to interconnect these parts
5. Megaloc blue thread sealant for regulator connections.


I’m the original owner of a Weber CEP-310 LP version bought brand new in Canada in 2008. This bbq has run well over the years, but I’ve moved into a house with an external valved NG quick disconnect. So I finally decided to make the switch from LP to NG. I bought the conversion kit from Majestic in the US (part 2 thru 4). This was my first mistake. I did not find this forum until after having purchased the conversion kit. That was my second mistake. After having found this forum, I purchased part 1.

The burners are still original and are discoloured and have a slightly rusted appearance. I gave them brushing when cleaning the bbq last week. After having installed these parts and passing leak checks, I lit the bbq. I could immediately hear the flow of NG, much more audible than LP. Lighting was easy. The flame burned aggressively and waved around a lot, with the control knob at high. I adjusted the air shutter to wide open, this reduced flame height and burned very blue. But the flame height still seemed too high and aggressive. Reducing the control knob to low did not result in any flameout/sputtering, the control seemed good.

I set the other two burners’ shutters wide open and set their control knobs to high. Easy lighting, with similar flame characteristics. I set all control knobs to high and videoed a heatup cycle. It took 38 sec to go from 200F to 400F. I have not converted a bbq, I have created a blast furnace ;-( This temperature rise seems far too quick for my liking, but flavourizer bars and SS grates are removed from the bbq. Running LP never achieved this type of heating “performance.” Also, I think the flame tip will touch the flavourizer bars at times, not what I want.

I’ve attached a third pic of the flame pattern on high. I’m asking your for your advice on next steps to take. My first instinct is to measure NG pressure, but I have no devices to do this. Note I do have a smooth acting isolation valve my house’s external quick disconnect. It appears to be a ball valve, it has a 90 deg stroke. Could I make use of this to throttle NG to the bbq ?

One final note for you. I want to run a NG extension line 33 ft to where my bbq’s permanent home on the patio will be. Currently, the bbq is moved next to the house’s NG quick disconnect, for testing purposes only. This will introduce some pressure drop and might help tone down my converted bbq’s performance, but I'm not expecting much.

Dave
 

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First, the air shutters do NOTHING to control flame/heat output. Bottom line your burners and air shutters don't care what gas you give them. There is no need to change anything. So put that all back the way it was. Secondly what is the pressure of the gas at the outlet on your home and where is the regulator set. You will need a manometer to find this out. The pressure coming IN to the regulator should be between 6.5 to 7.5 inches WC. If it's not you have an issue. Secondly your output from the regulator should be 3" to 4" WC. Again if it's not you have an issue. Until you know those values and reset everything the way it was there is no way to help you
 
This is the second time in two days that I have seen one of those Female 3/8" flare to Female 3/8" flare adapters. I just pulled them off on of my rehab grills yesterday. The guy I got it from said something about converting it for NG and the "hose was missing". I don't know if had been converted but the manifold has LP orifices in it, so I am guessing they just piped in NG and didn't convert it properly.Untitled.png
 
Try it with the flavorizer bars and the grates in it. Someone posted recently that their grill was running hot and it was just the bars and grates were out.
 
A video of the flames would be much more helpful. SOmetimes you take a photo and at the time a draft hits the flames and they look all messed up at that split second. If you do a video, do it on each heat setting for 4 or 5 seconds each and try to do it in a garage or when there is no wind.
 
Thanks to all who've replied. I'm going to rig up a water manometer to measure pressure. I cannot create a video of flame action in a sheltered area, my NG connection is outside in my pack patio. I'll reshoot a video when the night is calm.

On the housing of my Maxitrol regulator, it says Po 4.0”-8.0”. I interpret this to be the output regulation range in "WC. This does not align with LMichael's recommended control range of 3-4" WC. However, Weber manual 89479 (for the NG version of my bbq) clearly states:

This barbecue is designed to operate at 7 inches of water column pressure (.2526 psi).

I"m not sure what to make of this, but will reserve comment until I have measured inlet NG pressure. Stay tuned.....
Dave
 
Again here I don't know how your manifold is "jetted". I typically jet mine to work at 3" to 4" WC but if you're using a true basic stock Weber NG manifold from the US it should be jetted to work properly at 7" WC which is the pressure most (not all) homes in the US operate at. I have seen homes in MN in particular that were run with very high NG pressure into the home and then regulated down at the appliance connection. Don't ask me why, but I know what I saw. So bottom line if you have an actual NG manifold from Weber (not from a 3rd party who did a conversion), it should be just fine on 7"WC right from the pipe
 
Here in Ontario, covid rules make it impossible for me to walk into a store and rummage for parts to build a water manometer. So I pulled up the datasheet for my regulator. It has an adjustment screw. I progressively backed it off (2 turns CCW) until the flame was consistent and well behaved. After restoring the burner air shutters to their original factory position, reinstalling flavourizer bars and grates, I did another heat up. This time, the heat up closely matched the original performance when running on LP. Nice, slow, steady movement on the temp dial. Also, the noise due to gas flow was much more muted. I can only conclude my incoming NG pressure (whatever that is), was just a bit too much for my setup. Tonight is a test cook.

Now I"m happy with my set up. Now I realize it is advantageous to have an adjustable regulator for doing a conversion, lesson learned. This conversion took me quite some time, but I'm glad I took it on. Another advantage, I have a way to compensate for pressure drop when I extend my gas line outside, just tweak the screw CW. Thanks for all your help in bringing me over the finish line !
 
Glad to hear you got the gas pressure issue resolved. You've got a great grill there one of the last few years of sidewinders. Plenty of parts still available for it. It will cook circles around the newer (post 2010) grills.
 
Here in Ontario, covid rules make it impossible for me to walk into a store and rummage for parts to build a water manometer. So I pulled up the datasheet for my regulator. It has an adjustment screw. I progressively backed it off (2 turns CCW) until the flame was consistent and well behaved. After restoring the burner air shutters to their original factory position, reinstalling flavourizer bars and grates, I did another heat up. This time, the heat up closely matched the original performance when running on LP. Nice, slow, steady movement on the temp dial. Also, the noise due to gas flow was much more muted. I can only conclude my incoming NG pressure (whatever that is), was just a bit too much for my setup. Tonight is a test cook.

Now I"m happy with my set up. Now I realize it is advantageous to have an adjustable regulator for doing a conversion, lesson learned. This conversion took me quite some time, but I'm glad I took it on. Another advantage, I have a way to compensate for pressure drop when I extend my gas line outside, just tweak the screw CW. Thanks for all your help in bringing me over the finish line !
My HUGE question is why did you NEED one in the first place?! If things were done properly and you in fact have "normal" household gas pressures a regulator should not even have been needed! So IMO you still have an issue. You simply masked the issue
 
Dan, you are so right about this grill. It is very solidly built and still cooks evenly after 13 yrs. No substitute for quality. Weber is all I will ever own.

LMichaels, I purchased my Weber conversion kit from Majestic Grill Repair in the US, as they had very specific conversion instructions for my grill. So I trusted them and placed an order, which included the regulator. I did more research, as the conversion did not work very well at all. It was my mistake to trust Majestic. Only after finding this forum did I realize the need for a new manifold. I realize your question remains unanswered, what is my pressure ? I will try to determine this and report back.
 
My guess is they gave you jets sized to use a regulator. When I rejet one for people I ask them if they want to use a regulator or not. Some times I recommend one if the grill is on the end run of the house line. As pressure may fluctuate a bit. So I will adjust orifice sizes to accommodate a regulator and run the grill on 3.5 to 4" WC (though in Canada your measurement may be in metrics and I don't know the use there). See what you can find out.
 
Mayybe in Canada they have higher pressure lines? They probably measure in Barr.

if the grill heats up and you can go low too then you probably won’t have a problem there. If something is wrong with your gas plumbing or supply I’d worry about an issue somewhere else like a heater or something that comes on and off by thermostat. Worst things that can happen to your grill are too hot and no flame both are easy to know on a grill.
 
DSellors, did you ever figure out your issue? I have recently converted an older Weber Genesis from LP to NG (using an OEM NG Weber manifold for my application), and I am getting high temps (over 700 on high and around 500 with all three burners on low). Only things I have changed were the manifold, grates, flavorizer bars, and burners.
 
DSellors, did you ever figure out your issue? I have recently converted an older Weber Genesis from LP to NG (using an OEM NG Weber manifold for my application), and I am getting high temps (over 700 on high and around 500 with all three burners on low). Only things I have changed were the manifold, grates, flavorizer bars, and burners.
Maybe you missed his fix? He fine-tuned his regulator (see below).

Here in Ontario, covid rules make it impossible for me to walk into a store and rummage for parts to build a water manometer. So I pulled up the datasheet for my regulator. It has an adjustment screw. I progressively backed it off (2 turns CCW) until the flame was consistent and well behaved. After restoring the burner air shutters to their original factory position, reinstalling flavourizer bars and grates, I did another heat up. This time, the heat up closely matched the original performance when running on LP. Nice, slow, steady movement on the temp dial. Also, the noise due to gas flow was much more muted. I can only conclude my incoming NG pressure (whatever that is), was just a bit too much for my setup. Tonight is a test cook.

Now I"m happy with my set up. Now I realize it is advantageous to have an adjustable regulator for doing a conversion, lesson learned. This conversion took me quite some time, but I'm glad I took it on. Another advantage, I have a way to compensate for pressure drop when I extend my gas line outside, just tweak the screw CW. Thanks for all your help in bringing me over the finish line !
 
Maybe you missed his fix? He fine-tuned his regulator (see below).
Hi Ed, thanks for your reply. I just ordered a regulator like DSellors, but more so I was referencing LMichaels comments that the regulator is just masking a bigger problem. My NG supply has a regulator before the meter, which should be supplying 7" WC to all my NG appliances. Since my Genesis Platinum C NG manifold should be setup to run at 7" WC out of the box, I am wondering what my problem might be and why I would need a regulator in the first place.
 
Ed is correct. My conversion kit included a nice adjustable regulator, see above for the part number. It sounds like you do not have a regulator in your gas circuit, hence aggressive combustion.
 

 

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