Furnace and water heater, neither working on propane

[Moondoggie]

I just got home with my "new to me" 2016 Miramar 34.1. Last night I discovered that the gas furnace is not working, and this morning I discovered the water heater does not work on gas (but seemed to be working fine on electricity back at the campground).
First the furnace. With the outside cover off, I can see and hear the fan working, then after 30 seconds or so I can hear and smell the propane as the unit tries to kick in, but the furnace roar and the propane odor last for only a second, then it sputters out and drops back to only the fan. The furnace will cycle through this process three or four times, then the red fault light begins to flash (three quick blinks with a three second pause) indicating an ignition lockout fault. I can hit the reset button, but it just starts the cycle over again.
Meanwhile, the water heater, which worked fine at the campground on electricity, is not function on gas. With the outside cover off, I can see the igniter sparking, and it seems to ignite the gas, but like with the furnace, the fire lasts for only a second before sputtering out.
The propane tank is 3/4 full and the valve is open. The propane detector appears to be functioning properly and shows a steady green light. When I hit the test button, the lights all flash for a few seconds and the unit beeps as it should.
One other note that may or may not be a factor. The Miramar is 50 amp, but using an adapter, I have it temporarily plugged into a 30-amp receptacle (the electrician is due later this week to upgrade to 50 amps). I don't think this is the problem, though, because the furnace and water heater act the same way whether from 30-amp shore power or 50-amp generator.
I would sure appreciate any helpful suggestions.

[Chateau_Nomad]

Sounds like a propane flow problem... "fuel starvation". Are you ABSOLUTELY CERTAIN that your propane tank isn't empty? A propane gauge can be VERY inaccurate. Do the "idiot lights" on you inside control panel agree with the tank gauge? If you have a propane stovetop, does it exhibit the same behavior?

If everything worked fine at the campground then suddenly stopped as you describe... the FIRST thing I would resolve (for sanity) is to not assume the gauges are working and go get the tank filled - then test again.

[DavidEM]

Does the stove light? If not your propane is off. Your coach probably has an electrical solenoid at the propane tank that operates a valve on and off. Turn the switch back and forth and see if the valve clicks. If not, then there is a problem with the solenoid or the wiring to it.

And of course as noted above, you could just be out of propane and the inside gauge is incorrect. The one at the tank is usually more reliable than the inside level indicator.

David

[Sappy2]

Don't trust the gauge until you have filled the tank and vetted the gauge accuracy. If indeed the tank is full, then there is a issue with the system and I suggest a comptitent person look at it. As a tech from days past, if the car wont start, and no fuel at carb, and the gas gauge says full, I add 2 gallons and see what happens.

[16ACE27]

Stove working properly? Then probably not a propane issue. But the stove may work even if the propane regulator pressure is too low for high flow appliances like the furnace and water heater. Light all the stove burners and oven (if equipped). Of course, it could also be a dual failure of the control boards in the water heater and furnace. Both are high failure items and since you have no history on the coach you just wouldn't know how long they have been out.

[Moondoggie]

PROBLEM SOLVED!
As several suggested, I went out to try the burners. One lit immediately and burned for six or eight seconds then sputtered out. The others wouldn’t budge.
Took the RV to the local propane dealer , who was only able to squeeze six gallons into the 24 (I think) gallon tank. Owner of the place heard my conversation, grabbed some wrenches and started unhooking hoses and regulators. Turns out there was some blockage in the regulator nearest the tank. Owner said he thought he had a spare regulator in the shop. Came back and slapped on a new regulator and hose. 42 dollars for the propane, new regular and 45 minutes of labor. Now I have heat, hot water and a place to cook dinner.
Thanks for the suggestions. Seems everyone was on the right track, plus we experienced some fine small town service!

[16ACE27]

Originally Posted by Moondoggie

PROBLEM SOLVED!
As several suggested, I went out to try the burners. One lit immediately and burned for six or eight seconds then sputtered out. The others wouldn’t budge.
Took the RV to the local propane dealer , who was only able to squeeze six gallons into the 24 (I think) gallon tank. Owner of the place heard my conversation, grabbed some wrenches and started unhooking hoses and regulators. Turns out there was some blockage in the regulator nearest the tank. Owner said he thought he had a spare regulator in the shop. Came back and slapped on a new regulator and hose. 42 dollars for the propane, new regular and 45 minutes of labor. Now I have heat, hot water and a place to cook dinner.
Thanks for the suggestions. Seems everyone was on the right track, plus we experienced some fine small town service!

Great ending!

[Sappy2]

bravo!