General Info: Help/Warning Eno oven is worst

[Brewgyver]

Rob, the stove is made for LPG, as are virtually all** installed gas-fueled stoves in boats and RVs. It should NOT need an orifice change. Adjusting the air ring (which Tornado was referring to as "air gap") for the oven burner should be the only change you need to make. That can be done by sight, you want the flame color to be as blue as you can get it, with little or no yellow.

The composition of LPG is mostly Butane AND Propane, and may contain several other gasses, plus an odorant to help useres notice leaks. The makeup may be adjusted by the supplier regionally, with colder climates needing higher percentage of Propane, as the boiling point of Butane is just below 0 F.

Typically, the only strictly Butane appliances are the small, portable, most commonly single burner units you'll see caterers using. They use a can about the size of spray paint.


**The big exception being CNG (Compressed Natural Gas) stoves, which aren't very popular due to difficulty getting a refill, higher fuel consumption, etc.

[redneckrob]

Originally Posted by Brewgyver

Rob, the stove is made for LPG, as are virtually all** installed gas-fueled stoves in boats and RVs. It should NOT need an orifice change. Adjusting the air ring (which Tornado was referring to as "air gap") for the oven burner should be the only change you need to make. That can be done by sight, you want the flame color to be as blue as you can get it, with little or no yellow.

The composition of LPG is mostly Butane AND Propane, and may contain several other gasses, plus an odorant to help useres notice leaks. The makeup may be adjusted by the supplier regionally, with colder climates needing higher percentage of Propane, as the boiling point of Butane is just below 0 F.

Typically, the only strictly Butane appliances are the small, portable, most commonly single burner units you'll see caterers using. They use a can about the size of spray paint.


**The big exception being CNG (Compressed Natural Gas) stoves, which aren't very popular due to difficulty getting a refill, higher fuel consumption, etc.

Thanks, I came to that conclusion about the orifice too except I have read a couple of people specifically talking about changing it out so that leaves me confused (plus I like to try to use the word "orifice" in polite conversation as much as possible).
And I'm confused about what it is that I'm supposed to adjust on the air ring. The little 2" piece of angle iron in front of part of it? There's really no "adjustment" obvious to the rest of the ring absent taking a drill to each of the 40 or so holes to make them bigger which I'm sure isn't the right answer!

[Brewgyver]

All this is for a thermostatically controlled oven burner, if your unit has total manual control, all bets are off, and the air shutter would likely be at the actual gas valve that the knob is connected to. I've never seen one of those, but I know they exist.

I believe the air ring on the Eno is the same design at Force 10, though I haven't been able to find a picture of either. This pic is for a much larger burner on a Viking range, but it's the same design:


The hole at the foremost is where the burner slips over the orifice, and the sleeve that's partially covering the screen is turned to allow more or less air to be drawn in to mix with the gas. The one in the picture has a setscrew, but many don't.

One last word about orifices, since you like to talk about them. The orifice size is related to the delivery pressure of the fuel. I know Force 10 stoves specify 12" water column (30 millibars), and most LPG regulators deliver that. Apparently there are some European regulators that deliver at 15-20" wc, but Force 10 specifies the same size orifice for the oven burner for those pressures. They do have smaller orifices for the cooktop burners and infrared broilers for higher gas pressure.

[Brewgyver]

For manually controlled (adjustable flame height) burners, the air shutter is typically immediately downstream from the gas valve:

[Tornadosailing]

Originally Posted by redneckrob

Do you mind sharing a few more details about replacing the orifice and adjusting the air gap? I have the same oven, also on an FP. When I look at the burner in the bottom of the oven I see a U shaped tube with a bunch of holes in it that the gas comes out of. On the inner side at the middle is a bracket that holds the ignition unit and almost directly across from that is a bracket and a short (2 inch) piece of angle iron that holds the thermocouple and is perpendicular to the burner. Which leaves me unsure of:
1. Where is the orifice?
2. What is the model number and source of the "proper" orifice for propane?
3. Where is the "air gap"?

The manual shows an "air ring adjustment", from 8mm for butane to 4mm for propane but I can't tell what it's actually telling me to adjust from the diagram. And the eno parts catalog doesn't list an orifice in the parts list at all for those ovens. Thanks in advance for the help.

What model/year is your FP?

The orifice is only accessible after removing the burner assembly. It screws into the end of the gas pipe that remains in the oven after the burner is out. The orifice is available in the US from Force 10, but it took some talking to get him to sell me one. I have no idea what that's about. Normally if you ask for a part, a vendor will simply sell you the part.

The air gap refers to a hole in the burner that's partially covered by a sleeve located on the left side of the burner where the orifice is. The sleeve is adjustable to cover or expose more or less of the hole and affects the air/fuel mixture. I had a diagram that showed how to adjust it properly, but I can't seem to lay my hands on it. Force 10 should be able to supply you with this as well.

The thermocouple has to be removed from it's mount on the burner before you remove the burner. Care must be taken not to twist the thermocouple or make any sharp bends in it. The thermocouple is a very thin copper tube that breaks easily (ask how I know) and the oven will have to be removed and mostly disassembled to replace it. If you break the thermocouple the oven will light, but not stay lit when you let go of the knob.

I also believe much of my happiness with this oven is due to the stone I put in it. It evenly distributes the heat and keeps the oven temperature much more stable. https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

[Tornadosailing]

Originally Posted by Brewgyver

Rob, the stove is made for LPG, as are virtually all** installed gas-fueled stoves in boats and RVs. It should NOT need an orifice change. Adjusting the air ring (which Tornado was referring to as "air gap") for the oven burner should be the only change you need to make. That can be done by sight, you want the flame color to be as blue as you can get it, with little or no yellow.

The composition of LPG is mostly Butane AND Propane, and may contain several other gasses, plus an odorant to help useres notice leaks. The makeup may be adjusted by the supplier regionally, with colder climates needing higher percentage of Propane, as the boiling point of Butane is just below 0 F.

Typically, the only strictly Butane appliances are the small, portable, most commonly single burner units you'll see caterers using. They use a can about the size of spray paint.


**The big exception being CNG (Compressed Natural Gas) stoves, which aren't very popular due to difficulty getting a refill, higher fuel consumption, etc.

That's what the guy at Force 10 told me as well, but when I got the new orifice, I could see a slight difference in the size of the hole. I believe this was due to differences in regulator pressures from the european standard to a US regulator, but I don't know for sure. In any case, the burner has to be removed to adjust the air gap, and the orifice is a cheap part that can also become clogged.

I also know that nothing was done to change orifices or air gaps on my stove top, and it's a pain in the rear to adjust the temperature on. It's either way too hot, or the flame is on the verge of going out. There's not much in between. Not sure if this is due to orifice/air gap problems, or if it's just the natural condition of this stove top.

[Tornadosailing]

Originally Posted by redneckrob

And I'm confused about what it is that I'm supposed to adjust on the air ring. The little 2" piece of angle iron in front of part of it? There's really no "adjustment" obvious to the rest of the ring absent taking a drill to each of the 40 or so holes to make them bigger which I'm sure isn't the right answer!

If you don't belong to the facebook FP owner's group (there are two, the one with the stern of a Helia for the cover photo is more active) you definitely should. There are several discussion threads on there about Eno ovens and temperature issues. I dug up one of the threads where I commented about getting a #68 orifice from Force 10. Still couldn't find the instructions for air gap adjustment.

[Brewgyver]

The cooktop symptoms you describe could definitely be caused by an undersized orifice. If your stove was built for the older, higher pressure (20" wc) Euro regulators, they would have smaller orifices.

Of course, they could also just be dirty. Best is to remove them (7 mm hex socket), soak in alcohol or similar solvent.

[redneckrob]

Thanks so much for the help everyone! And as an aside, thanks for restoring my faith somewhat in my memory; I could have sworn I read a detailed post on this and assumed it was here on CF so I was pulling my hair out trying to find it, but it was actually on the Facebook group!