water heater and furnace issue

sorry for the lack of updates, I have been at the deer lease all week without internet service... it was great! lol
anyway back to the problem at hand. I brought a low pressure regulator, hose and separate bottle with me when I went to deer lease. I removed the flexible supply line from the existing regulator and found no blockages in the hose. I then hooked up the regulator and hose I brought with me, and got the same results, water heater did not work. I then opened the water heater cover plate to inspect the flame sensor/igniter. I removed the igniter and cleaned it with a scotch bright pad. I reinstalled it and bent the igniter plate so the tip was deeper in the flame upon ignition. the water heater started working fine! I am not sure if cleaning it fixed it or repositioning it deeper in the flame did the trick? I didn't have any noticeable corrosion in the igniter, but it did look "new" when I reinstalled it. I just replaced the igniter/flame sensor last summer but it did not correct the problem. maybe the connection was corroded and when I removed it and replaced it, it made good connection????
as for the furnace, I did not remove it to work on it yet. I have to completely remove it from under refrig cabinet to do any work on it. It may just be a coincidence they both started having problems at the same time. the furnace will work if I try to restart it a couple of times. I will tackle it at a later date.
I did have a brownish residue inside the supply hose from the regulator to the hard line on the trailer. not sure if it is something from the tanks or just something in the gas? it wasn't sticky or anything, just a thin dark oily substance.
I reconnected the existing regulator and flexible supply line and the water heater continued to work fine.
thanks for all of the help

Simple manometer

I measured and fixed a gas issue with my system this past weekend. Generator was taking several tries to crank. Frig wasn't cooling good when on LP (maintaining only 45 degrees). Everything was working good on 12V and 120 AC. Several on RV.net said was low LP pressure. My regulator was at about 8" WC. Replaced it and "new" regulator was at 14" WC. Took it back and second new regulator was set at 12" WC with no flow and dropped to 11.5" WC with all three stove eyes on high. This was dead on what most say it should be.

It is very cheap to make a U tube manometer. I bought about 10 feet of clear tubing at Lowe's. Mounted it on a piece of plywood with a few screws on either side of the tube with free leg about 3 feet long. Couple of drops of food coloring in some water. Fill the tube until you have about 12" of water up each leg of the U tube.

Mark the level of the water in the 3' leg at rest and every half inch above that for about 8 to 10 inches. The actual measurement is the difference of the water levels in the two legs of the U tubes but you get the same info by measuring one leg and doubling it. (a good measurement will be about 5 1/2" measured or x2 is 11" of water column.) (It doesn't have to be exact, just close.)

Connect the longer leg of the tube to the output you want to measure. You'll have to come up with what ever adapter is needed to fit each output.

Since you are having issues with all appliances, I would start at the regulator work my way away from the bottles to find the blockage. If you have a low point in the lines, I've heard some have found oil accumulating and blocking the flow.

Be careful, it is gas.

You might consider hooking up a manometer to the system to see what kind of pressure the regulator in putting out. It should be 10 1/2 to 11 inches of water column with two appliances running. I had the same problem after replacing my regulator, come to find out the new reg. was only putting out 5 inches of water column.

Just a though.

Does the rubber line from the output of the regulator to the hard pipe under the trailer have any p trap(dip) or loop in it? You should be able to take this line loose from the trailer hard pipe, open the LP tank and you should smell and hear a good rush of LP. If NOT, you have a regulator/switchover problem. If you do have a good rush of LP, then you have a restriction in the underbelly frame piping supply. Doug

I would take the flex line off that feeds the rigid line and inspect it or replace it.
I would not think that the rigid line could be an issue.
Yes, you could take a major line loose and use a strong air compressor to blow out the lines. Remove line from tank area so as to blow only the pipes and not any device such as gas valves.

yea I have thought about that as well. I think I can hook into my quick connect for my outside grill and blow back out the front where the supply line ties into the regulator. that way if some trash got lodged in the line restricting it somehow it will blow it back the way it came.

Plugged gas line is my next thought. Pull everything apart and with an air compressor connected check for air flow. 5PSI should be more than enough pressure to check things out.

both bottles are on the front. they are both hooked to the same dual regulator. I have tried both bottles, and tried switching the bottle configuration, even brought another bottle from my grill at home.

are both your bottles on one side or split on each sideif so is this problem when use a certain side