The gas oven temperature mistery 2861

I understand that there are a couple of differences between LP and NG appliances: orifice size, line size, and pressure (n.and maybe burner port size (the holes around the ring wherte the gas comes out to burn)

1) LP has over twice as much energy per cu ft as NG.

2) If you have orifices sized to deliver 12,000 BTU for an oven when using NG at a given temp and pressure, and you put LP gas through those same orifices at that temperature and pressure, you will have maybe 25,000 BTU delivered into the oven.

Thus if you feed a natural gas oven's orifices with propane, they will run hot at the low end, where the minimum amount of gas allowed by the valve provides more heat than the oven loses, and thuis the temperature balance is struck by the minimum BTU fed and heat loss, rather than the amount of energy let in by the valve and the heat loss (I hope that was explained clearly).

The thermostat should still work in the higher temperature ranges.

3) There are also problems with using a LP rated gas valve with NG - LP pressure runs around 11" water, and NG around 4" water - and because of orifice characteristics and gas weight, it gets kind of messy when the pressure changes. (I also think the valves deteriorate if the wrong fuel is used in the valve.)

Considering pressure (off the top of my head on this): having LP running through a NG valve delivers less LP gas than an LP valve would, BUT I believe that roughly the same amount of gas is delivered as if it were NG and thus delivers about twice-plus the energy to the oven.

If you run NG through an LP valve and it enters the NG-sized orifice at 11", then the NG is coming in at a higher pressure, and it may limit in the NG orifice.

If the NG enters an LP-sized orifice at higher pressure, I htink it will would run about the same or cooler as LP.

fwiw