Water Heater will not stay lit

[Beginner]

My water has electronic ignition instead of a pilot.
It wont stay lit.
I have cleaned the gas orface.
I have cleaned and greased all the push on terminals, replaced all the female push on lugs and plugged and unplugged the gang connector on the brain unit several times but to no avail.
I'm sure I'm not the only one to experience this.
Help
Beginner

[dwightdi]

Sometimes a film develops on the flame sensor if your system uses one of these vs the old fashion thermocouple. I have had it a few times in home systems with electronic ignition. The professional HVAC guy which I use showed me how to use a dollar bill (It has just the right amount of abressiveness) to clean off the surface of the sensor and then the thing works fine. It cuts out because the sensor is saying it does not see a flame and turns off the valve.

[HowieE]

While it is lit what does the flame look like. Even pattern and more blueish than yellow? If the color or pattern is bad I would check the gas tube, not the orifice, again for a spider. They get way up in there.

Another thing with thermocouples. With a small wrench brake the connection at the gas valve and reseat it for a GOOD CONNECTION. You are only working with milie volts here and a bad connection will cause a problem.

[dwightdi]

Electronic ignition gas appliances do not use a thermocouple because they do not have a pilot light to heat the thermocouple. They depend on a spark (like the Suburban furnaces do) to ignite the gas.

[HowieE]

It is snowing here at the moment so I did not go out and look at my heater but I am sure there is a PROOF OF FLAME device connected to the gas valve. Check the connection.

[TomW]

Originally Posted by dwightdi

Electronic ignition gas appliances do not use a thermocouple because they do not have a pilot light to heat the thermocouple. They depend on a spark (like the Suburban furnaces do) to ignite the gas.

Your generalization is incorrect.

Many electronic ignition gas appliances spark a pilot light whose only job is to run long enough to warm a thermocouple which signals the electronics that gas is burning. The electronics will then fire the main burner.

When the thermostat signals "warm enough", all gas is shut off including the pilot which warmed the thermocouple.

Tom

[crestonrv]

atwood does have a help line. all flame driven appliances have a "thermocouple" of sorts. yours has a thermal generator which makes appx.10 mvdc if all connections have been cleaned,flame burns mostly blue while lit,
is probe immersed in flame? if so - remove ignition module/board and take with you to your rv parts dlr. they should be able to test it for you and sell you a new 1. 1984 = 23 years old , that old fenwall board has long since paid it's own way.and probably is just not picking up the miniscule signal from the probe. if a new board is called for buy a dinosaur board (appx. 110.00) they have a 3 yr warr. and i have been using them for 12yrs here without a prob.
your cable is it the spark plug type? check that as well (any wire will work for test) if it lights you up the board is good-ha ha. sometimes you gotta spend a buck on the old a/s to keep it going. crestonrv@yahoo.com e-me for
# and i'll walk ya through it. ps If the flame is yellow clean out spider web in
tube

[Beginner]

Thanks guys
1. Because my house has a gas floor furnace (pilot light), I know what a Generator and a millivolt thermostat looks like and operates like.
2. I have a gas water heater and it uses a thermocouple. Repaired/replaced that.
3. By process or elimination the water heater has to have a flame sensor.
First the flame is yellow. It was yellow after I cleaned out the orface in the Gas safety valve. I'll pull the air mixing tube/burner assembly off and inspect carefully as soon as it warms up a little (its 25 degrees here)
Next the spark jumps the gap (white spark, 3/8 inch gap or so, I'll pass on the grab test, I've hit enough lawn mower spark plugs).
I know that flame sensors can go bad. I had to deal with a gas fired boiler in a building for a while and boiler guy replaced the flame sensor once to fix a reliability problem.
Thanks again.
Now I have a direction to proceed in.
The trailer is winterized and it will be spring before I get to run again so I'll check the orface, clean the air mixing tube/burner and just replace the flame sensor in the spring.
Thanks again.
Beginner

[Beginner]

dwightdi
Thanks a lot. I had my bride hold the assembly while I buffed both wires with a dollar bill. It tore up the dollar bill.
Just got back from the breakout rally monday and the water heater worked just fine.
Thanks again.
Beginner