Typical inlet pressures run 11-14" WC which is controlled by the second stage regulator often found on the outside of your house
Because i only have 9.5 to 10" going into the regulator.Don't think I have ever seen a furnace that had the same manifold pressure as its inlet pressure.
Should still light okay at 10" manifold. But on horizontal applications, it can cause a problem.
Why can't the reg be turned up to 11"?
This is how I actually discovered that it was not lighting the first time. The hot surface igniter was dead. I suspect from having to continually cycle. I replaced the igniter and discovered that the top 3 burners always light initially but the bottom burner does not always light in enough time that the system senses a problem and shuts down. Even when the bottom burner does light it is always somewhat delayed. I have tried moving the bottom burner to the top with the same results, so ruling out a problem with the burners.Tank low? Sounds silly, but I've have enough calls to empty tanks.....
It doesn't light at all the first time or 2, or lights but then shuts off, retrying after that? Spark ignition or hot surface igniter? (hsi will glow red hot, instead of sparking) if you have a hsi, check the amps to it when it's trying to fire. Hsi's get old and can start to fail to light when the current draw is low. (resistance is climbing due to the stresses that it endures)
Cheers!
Should I have the LP company raise the pressure?Typical inlet pressures run 11-14" WC which is controlled by the second stage regulator often found on the outside of your house
If you only have 9.5 to 10" going into the regulator. You have a gas supply problem between the tank and regulator.Because i only have 9.5 to 10" going into the regulator.
Sorry for my terminology confusion. Is the secondary regulator something I can adjust? I assume the primary reg is the one on the tank and the secondary is the one where the gas line enters the house. Does it adjust just like a normal gas valve? (clockwise to increase pressure)?If you only have 9.5 to 10" going into the regulator. You have a gas supply problem between the tank and regulator.
Oh, your calling the gas valve a regulator. It has a reg built into it. But its not considered a regulator.
Your house reg/secondary regulator can be turned up to get a higher pressure to your gas valve.
Yes, CW to increase.Sorry for my terminology confusion. Is the secondary regulator something I can adjust? I assume the primary reg is the one on the tank and the secondary is the one where the gas line enters the house. Does it adjust just like a normal gas valve? (clockwise to increase pressure)?
Yes, but good question, thanks.Did you pull and clean the orifices.
Yes. I thought this was going to be the problem from the very beginning. The very first thing I did was to remove them and cleaned the wings on the burner bars. The reason I swapped the bottom and top burner was to see if I had an issue with the burner. Unfortunately, the results were the same.And clean the crossover channels?
They are the little burner bars to the top and bottom of each burner. There should be a flame from them during operation.
The flame looks clean and burning well. That's a fairly normal light off, just a hair delayed. Something is distorting the gas flow before lighting.
Cheers!