Trouble with LP water heater

[ReedZ]

I have an older Attwood LP water heater from the mid 90's and recently I've been having trouble getting the pilot lit. The only way I am able to get the heater going is by holding the lighter underneath the thermocouple. After doing that for approx a minute I am able to turn the switch to the on position and the heater fires and runs fine and the pilot light now has a flame on it and stays lit for the rest of the weekend until I shut it off to go home.
This happens every weekend when I initially try to light the pilot. I've tried turning the gas on when I first arrive and let it run for a few minutes while I open up thinking it might take time for the gas to run from the front of the trailer to the back but this doesn't seem to do anything.
I'm not sure what would cause this and am hoping someone here with knowledge of these things will know the answer and how to fix

Thanks in advance

[ReedZ]

Hey guys
Just wanted to give you an update
Last weekend I replaced the thermocouple and the problem is solved
Thanks very much for your help!

[nomad297]

Replace the thermocouple. Done.

Bruce

[ScottG]

Since it eventually ignites and heats the water, the TC is working but just not very good. It may not be situated in the flame correctly, it may be insulated with carbon, not getting hot enough because of flame condition or intensity or it may be a combination of all these things. The orifice and pilot can be partially blocked as well making them inefficient and only partially functional.
We're basically asking you to do a tune-up on the WH.

[ReedZ]

Ok
A little confused now
If the pilot flame works fine after I get the heater going as per my OP why would I need to do anything with the pilot itself?
If the pilot was plugged then it technically shouldn't run period is that not correct?
Just a bit confused now based on the last couple of responses

[RJsfishin]

I coulda swore the problem was the pilot flame. Why would we change the TC that the OP has proven to be fine ?
Right on for the "Clean pilot orifice" !

[Gjac]

Yes the part that sticks into the flame. You can also remove the spade connector where it goes into the control module and make sure there is no corrosion there also. Don't use a pipe cleaner or pin in the orifice just soak in alcohol and blow out with air.

[ReedZ]

Thanks for the responses
I have a question about the thermocouple. The part that you're saying I should clean with a brush, is that the probe that is immediately above the pilot or are you talking about the part that screws into the controller
Also. To clean the pilot flame orifice what should I use? Would a pipe cleaner work?

[Gjac]

Also after the tip is cleaned make sure the tip of the thermocouple is directly in the flame and the tip is at the right gap. There is a right angle baffle at the end of the burner tube that can be adjusted, rebent to 90 degrees at parallel to end of the tube as you look down on it. The Atwood manual will show you a description of this.

[Old-Biscuit]

ScottG wrote:
Use a brass brush to gently clean the thermocouple and get the carbon off it. Many of them are replaced when this is all they need.
It doesn't cost anything to try first.

And clean the pilot flame orifice with some alcohol

[ScottG]

Use a brass brush to gently clean the thermocouple and get the carbon off it. Many of them are replaced when this is all they need.
It doesn't cost anything to try first.

[rk911]

newman fulltimer wrote:
change the thermal couple

X2

[newman_fulltime]

change the thermal couple