Water heater on gas - Hi-Lo camper travel trailer forum

Papa · 03-27-2012, 11:59 AM

We normally camp with hook ups except for a couple of times a year. When camping with electricity we use that power to heat water. When we camp without electricity we use gas to heat water.
We have a 2805C which has the gas bottles on the front of the camper and the water heater located on the other end (rear driver's side corner) of the camper. It is as far away from the gas bottles as it can be mounted.
I have noticed that when we attempt to run the water heater on gas that it seems to have problems lighting. I have wondered if the difficulty lighting could be because of the location so far away from the gas source? It finally does light but it make take several tries. Seems that it tries three times to light. I seem to remember the book saying that should it fail to light after three attempts to wait 10 minutes before trying again.
Has anyone experienced a similar problem and if so what did you do to correct the problem. Or if anyone else has suggestions I'd appreciate hearing about a solution. Thanks in advance.
God Bless
Papa

retiredcamper47 · 03-27-2012, 12:27 PM

Hi Papa,

Whenever we get to a campsite, we always purge the gas lines of air by turning the gas on and lighting the stovetop burners. Once the burners light, all the gas appliances work great. If we don't do this, we have a hard time to get the furnace or hotwater tank to ignite. Hope this helps.

Bob

Papa · 03-27-2012, 05:48 PM

Bob, Thanks for the reply. Due to the lay out of the 2805 C model Hi Lo the stove is within 4 feet of the gas bottles while the water heater is way down the other end of the camper. About 25 feet away (down stream) from the stove. I do agree it must be that the pipe feeding the gas to the water heater is not full of gas but rather has air in it.
I wish there was a vent for the gas line back at the water heater area of the camper...........but then I might blow up the Hi Lo if there were. ha
Thanks again for your reply.
God Bless
Papa

Papa · 03-27-2012, 05:51 PM

Bubbie, thanks for the reply. Do you have any tips re adjusting the air flow to the burner? And could an out of adjustment make it hard to light? I've just assumed that since the water heater is so far from the gas supply that the line leaks some and has air in it?
Thanks for the help.
God Bless
Papa

sam · 03-27-2012, 07:41 PM

Since your unit is 6 yrs old you might consider having a propane leakdown test done. This will show if you have any leaks in the propane delivery. This Friday we are going to have our Rv dealer do this and also our insp. We have never had this done and I think it doesn't cost a bundle to have done. Good peace of mind as our units age.

retiredcamper47 · 03-27-2012, 08:00 PM

Papa,

My HiLo is a 29' model. My kitchen is about 8 feet from the front on the curb side. My hot water tank is also located at the rear of the trailer on the street side.

Bob

Papa · 04-03-2012, 12:01 PM

Hey Again PaPa! I have never been able to figure out how air under atmosperic pressure can get into the gas line but doggone it, sometimes I believe it must too!
Assuming you have an Attwood unit like our was, there are 3 or 4 ways I'd suggest. Others on the Forum may have other/better ideas too:
Look at your service/owner's manual for adjustment procedures, check youtube for how-to videos, have a RV Tech use a manometer to check your propane system (including the regulator) or if your other gas appliances are working fine, (burner patterns on your cooktop is a great way to tell if your propane pressure is good), just light the water heater and play with the little register that controls the air on the burner.... If it is real noisy, probably too much air..... You do not want a flame that is yellowish or lazy either. Mine worked great after adjustments! It should be relative quiet with the water heater door closed from ~ 8 feet away.... Good Luck and God Bless Ya! Bob (aka Bubbie - grandpaw tagged me that in the 50's)!

Bubbie,
Seems that the gas regulator reduces bottle pressure down to 11 inches of water. Found that 11 in of water is equal to 0.4 PSI. Atmospheric pressure is 14.7 PSI. So if I understand this correctly the gas line will always have more pressure on the outside of the pipe will always have atmospheric pressure (14.7 PSI) acting on it. The gas line when the gas bottles valves are open are only placing 11 in. of water (0.4 PSI) in the gas line. So it looks like the outside pressure of the air is always greater than the pressure in the gas line? I would then assume that air makes its way into the gas line. If the valves are off then it seems they would fill up with air? Does this make sense to anyone? Or am I just not seeing something here? Maybe if there is a small leak it is leaking air into the gas line.
God Bless
papa

RichR · 04-03-2012, 02:12 PM

Could temperature changes cause air to get into the line. Warmer temperatures would tend to force expanded gas out of the line and then cooler temperatures would tend to suck air back into the line. Assuming no gas line is perfectly leak free.

Papa · 04-03-2012, 05:01 PM

Could temperature changes cause air to get into the line. Warmer temperatures would tend to force expanded gas out of the line and then cooler temperatures would tend to suck air back into the line. Assuming no gas line is perfectly leak free.
__________________
RichR,
Yes temperatue does have an effect on gas pressure, i. e. a pressure cooker.
But one could think that the temperture would effect the gas in the line the same as the air surrounding the gas pipe.
Temperature aside under normal operations (if the two stage regulator is putting out the correct second stage pressure of 11 inches of water column) the pressure in the gas line is never greater than the atmospneric pressure. With the gas valve on the gas pipel pressure inside should be 0.4 PSI (which is equal to 11 inches of water) and at the same the atmospheric pressure (at sea level) is 14.7 PSI. Seems to me at all times the pressure outside the gas pipe is a lot greater than inside the pipe?
I'm thinking that air could get in the line before fas would leak out.
God Bless
Papa

Papa · 04-04-2012, 05:45 AM

Hey Papa, Those PSI numbers getting tossed around can be confusing. Atmosperic pressure measured by scentist and engineers = 14.7 PSIA (A for absolute) or 0 PSIG (G for gauge). When most of us refer to PSI we are using PSIG. The propane pressure is measured in PSIG as is the Atmosperic pressure as we use it. The propane pressume must be slightly higher to operate our appliances.
Now whoever decided to use 2 types of pressure measurements wanted us to be confused or just make everyone think they were super smart right?
We should probably just purge the air and have fun camping!!!!
Probably something simple such as a trip valve leak on the water heater of furnace???? God Bless Us All - Let the camping begin!!!!
__________________
Bubbie,
You are right in one thing you point out............it's getting too confusing........lets just GO camping. ha
My original problem of the water heater operating on gas seems to have difficulty lighting the first time does still bother me. But I don't dry camp that much any more and I don't have any problem in camp grounds with electricity. So like a friend of mine says "bump it".
We are planning to take our first trip of the spring on Wednesday the 11th of April. Will take three of our grand sons for four days then catch up with our adult camping group for a week. So now I have to get the camper ready for CAMPING.........which we all should do more of.
GOd Bless
Papa

RichR · 04-15-2012, 08:02 PM

I have learned that after you turn the valve on at the tank wait a few minutes for the pressure to level out in the lines because of the safety check valve on the tank. Then the gas should flow better. I have had fits with a 20# tank and my WeberQ grill because of that. I turn the tank valve on at least 15 minutes before lighting the grill, then all is well.

retiredcamper47 · 04-24-2012, 05:39 PM

Papa,

Did you get my pm?

Bob