Atwood G6A-6E not lighting. Possible gas valve issue?

[Useroverdrive]

Hello all,

This will be a bit of a long post but I want to know if I covered my bases before posting.

I have a 1989 Mallard Sprinter class A. The water heater is a Atwood G6A-6E 6 gal electronic ignition wh. On a trip a couple of months ago, I noticed the wh having trouble keeping a full flame. It would cycle on, but after a while seemed to almost "choke out" but not quite.

Back at home base, I didn't turn on the wh, although I keep water in the system. I noticed during a walk around that the PRV was weeping and it had been leaking onto the main burner tube so I resolved to fix that. I bled the PRV to get an air bubble back in the tank and replaced the burner tube.

I attempted to start the wh and was rewarded with the clicking sound but no "whoof" sound like the wh ignited. There was no air in the lines as I started the furnace and stove beforehand. I have done the following: taken every connector loose, cleaned and reconnected. Cleaned the flue with a bottle brush and blew out with compressed air. Replaced the spark probe assembly because the original had some cracks in the electrodes.
I had a helper inside the mh turn the ignition switch on and off while I checked the electrical connectors outside. I had power (12v plus) to the board, wires to the eco, wires to the stat, red wires from the eco to the gas valve. the green ground I made sure was seated. At this point I am only smelling a very tiny bit of LP, barely noticable, then its gone.
Should I be able to hear the solenoid open at the gas valve? A clunk or squeak maybe? I dunno what else to consider at this point and I don't want to spend $500 replacing parts until the problem works itself out.

I think I've covered most of the bases but if I didn't write it down, let me know

Thanks in advance and if this post needs to be moved, go for it

DS

[wasatchmtnatvr]

or bought the coil only?

[BrianinMichigan]

awww you should have rewound the coil.:)

[hotpepperkid]

Call ATwood and they will walk you through the trouble shooting

[enblethen]

Thanks for the update!

[Useroverdrive]

Success! It was the gas valve. I ordered a new valve yesterday from Makarios RV and (no lie) Fedex showed up this morning. The part shipped out of Georgia. Anyways, I installed the new valve and was rewarded with a "thunk" when the valve opened and a whoosh of proper flame.

I'm letting the water heat up to test temp and if water temp is around 140 degrees I'll call this task done.

Thanks to everyone that posted suggestions

[Useroverdrive]

Brian, I checked the gas valve for continuity earlier and 1 side is bad. I think I've isolated the culprit. I'm taking a few days off from the beast and will get back on it after turkey day

[BrianinMichigan]

Overdrive, Do have a ohm meter or have access to one. I believe there are two valves on the gas valve. Pull the wires on both of the valves and measure the resistance of the coils on the valve. i believe they should be around 90 ohms. When mine stopped working one of the coils opened up but the valve sounded like it was working because of the other valve clicking. I found the wire on the coil had oxidized so bad it fell off of the coil. I unwrapped it a couple of turns and soldered it back on. It worked for a year or so and I had to do it again. That when I bought a coil of magnet wire and re-wrapped the coil. It's been about 6 years and it's still going strong.

[enblethen]

This will give you a little more information on comparing the boards. Temporary switching doesn't have to be bolted in. It just needs to be connected up. Big difference is the ignitor connector. Spade versus post.
Dinosaur

[Old-Biscuit]

Atwood gas valve (White Rodgers #93870) less than $100.....LINK

[Useroverdrive]

The ignitor board part number is MPD 91731, obselete (of course lol). The furnace is a hydroflame but but I will check the board. The furnace will run you out of the motorhome

[enblethen]

Look at your furnace and refer to see if they use the same ignitor board.
You maybe able to switch one of them to test the water heater.
You can test the gas valve coils. Both coils should have the same resistance.

[Useroverdrive]

wa8yxm, I looked at the dino boards to replace my atwood 91731 board and that may still be an option. At this point it is replacing the board or the old type A gas valve. Both are about the same price

[Useroverdrive]

Agreed Old Biscuit. I'm going to to take Beast to the rv place and have them double check my work. I do agree with you though.

Yes fpresto I was full of guano re: 500$ on parts. My point was simply that I didn't want to spend the same amount of denero replacing parts when I could have bought a new replacement for less. Point taken and noted. Next time I will use simile instead of wit
🙂

[wa8yxm]

You said you heard a clicking sound..

Was it CLICK,, then perhaps 10 seconds later CLACK

or was it Snap, Snap, Snap, Snap?

Did you smell propane?

The first is the sound of the solenoid, if you hear that you should smell propane.

The second (Snap, snap, Snap) is the sound if the ignighter, ON mine, I did not hear that sound, As a result I had to replace the control board, And due to time limits I could not order what I needed from Americcan RV in california and no local dealer had dino boards so I got another attwood box. (Not happy).