Atwood water heater won't light

[Arsist]

2010, 6gal, used maybe 20 times, gas only unit, manual pilot.

Fired right up and ran fine. Hours later I noticed the water wasn't very warm. Found the pilot was out and I couldn't get it to relight. Tanks both full enough and stove is working.

Thermocouple tested at 25 mV. I'm getting no LP through the valve (RobertShaw). Pulled the line before the valve and getting LP there. I'm thinking something in the valve, ECO maybe?
Do I have to replace the whole valve assembly?

[phays]

go here http://bryantrv.com/docs.html

Near bottom of page are the water heater service manuals.

[Arsist]

No, no gas flow with TC warmed.

[Old-Biscuit]

Unfortunately the ECO is a one shot device........when they open it's permanent and part of the gas valve.

Pushing knob in at pilot position would allow gas to pilot.
Pilot flame heats thermocouple which sends mV signal to magnet which lets gas control continue to send gas to pilot....then a mV signal goes thru ECO back to thermocouple which completes the circle.

Magnet only needs 12 mV or more to stay open.

If you heat thermocouple with a BBQ lighter can you get any gas flow?
If not then suspect ECO tripped.....new gas valve!