Atwood G6A-8E water heater clicks but gets no gas

[Rvanelife]

I have a 1999 Winnebago that has done me well for many years. I also fix or replace things as they wear out and my Atwood Propane only Water Heater is starting giving me issues. At first it would lite, but then within seconds it would quit. I could hear the propane turn on and the clicking... I checked outside and could see the blue flame, but it would just quit. Watched a lot of You tube videos and did all the tests, checked the thermal fuse for continuity, checked the voltage at the fuse and at the ECO (both thermostats show good continuity and the voltage checked out as well. Took the tube assembly off and cleaned the tube, and put it all back together. Started it up and YES.. the burner lit up with a nice blue flame and stayed on.... So I turned the unit off and started it again and YES... the burner lit up again just as it was suppose to.... WELL....then 5 hours later went to start it up and NOTHING.... The gas is not working and you can hear the clicking to start but no gas. I checked the voltage at the ECO and it was good at 12.6 volts. Everything else seems fine and propane is full (Stove and oven inside work fine) ... So could it be the control panel, is it the solenoid gas valve or am I missing something ?

 

[creativepart]

I would think the possible culprits are the Control Board, the gas valve or the flame sensor.

But I’d start with the Control Board. They’re known to be problematic.

 

[Morich]

I might go to the small stuff first and check before replacing any parts. Find the wires which go to the gas solenoid and connect a meter there. That will let you watch the meter as the heater first tries to light. There are specific steps needed to do it right. It seems you are getting most of those done correctly, but at some point the gas solenoid is not opening or not staying open. Watching the electrical signal to that solenoid can help you spot if you have a problem with the signal/power not getting from the board to the solenoid or is it a problem with the solenoid not opening and staying open?
At some point it is also important that the gas does reach the clicking that should light it. The is a tiny opening (orifice) that can get a bit clogged but that part should come after the solenoid opens and stays open long enough to let gas flow to ignite. Maybe worth a close look at the tiny hole to be sure spiders, mud daubers, etc. are not working on you?
But before that, the signal from controls to solenoid need to be verified!
Point of causion? Don't get too rough with cleaning that little opening and shoot your foot by scraping too hard, etc.
Steps are, signal to gas valve, it opens, and ignition starts. Assuming it lights, then a flame sensor in the flame tells the board to let it continue to heat. At some point the flame sensor has to find the flame is good to avoid shutdown but it seems you are not getting to that point.
Seems at this point I would want to watch a meter on the power to the solenoid to see if drops when power is still there or does the power drop to make the solenoid drop.
This seems to be a very good manual, though possibly over careful to make it longer than often needed, it does seem to cover ALL the bases!

Atwood G6A-8E Water Heater Service Manual | Water Heater Manuals

Atwood G6A-8E Service Manual. The Atwood G6A-8E water heater is a high-quality and reliable appliance designed for providing hot water in RVs and campers. With ...

www.waterheatermanuals.com

 

[klook]

Cleaning the spark contacts and making sure they are set at 1/8 inch. They have to be positioned correctly in the gas to ignite it. Plus they ground thru the mount. You can ohm out the gas valve, find the correct ohm reading for that model online. Sometimes they click or thunk but don't open.

 

[Rvanelife]

Thank you all for your responses. I am perplexed because after I did all the cleaning and checking for continuity and voltage.. it worked... twice as it should. Now all it does it "click" like it wants to try and light, but it is getting no gas. I did check the gas orifice and it is wide open clean. And I do have power (12.5v) coming from the EOC which connection goes to the Gas Solenoid. I dont know exactly how to test the solenoid, but if I have power to the wires going to the solenoid/gas valve... then it appears to me the gas valve needs to be replaced. Thoughts?

 

[klook]

You need a meter capable of reading ohms. IT should be between 40 to 48 measuring individually, and 20 to 24 measuring both together.

 

[Rvanelife]

You need a meter capable of reading ohms. IT should be between 40 to 48 measuring individually, and 20 to 24 measuring both together.

 

[Rvanelife]

I do have an meter that can read ohms... sorry but I have no idea what you are talking about when you say 40 to 48 individually or 20-24 measuring both together. both what?

 

[klook]

Gas valves have 2 coils that open and close 2 valves. It is a safety feature. If you look at the gas valve it has wires that go to 4 spade connectors. One side is ground the other power. Measure between the 2 on one coil is individually measuring.

 

[klook]

Look at the wires and it should explain itself

 

[RayIN]

Sometimes the thermocouple contact will get corroded and block the miniscule 4 milliamps generated by the thermocouple. The small tube from the thermocouple to the gas valve gets corroded and must be cleaned off with a pencil eraser. Unscrew the tube from the gas valve and clean the bulb on the end of the tube with a pencil eraser, then gently clean the mating contact in the gas valve.
When re-inserting the tube and tightening the nut, use care not to over-tighten. If the bulb is crushed it ruins the thermocouple., Snug is tight enough IMO..

 

[Rvanelife]

UPDATE..... Thank you all for your help. After noticing I did not have a 'spark' to lite the propane even though I showed I had 12.5v ... I figured it must be something connected with the control box. Before removal there was a "notice" from the mfg. next to the box that said "before replacing control box remove control box and check all connections" (which I thought I did) but did not remove the control box. So I removed it, cleaned it and all connections and checked all grounds (which I think was the issue). Water heater started right up.... Thanks again... patience and a little help from my friends paid off.