Atwood G6A-4E water heater LP valve not working

[shortbus]

My water heather stopped firing up the other day. I did some basic troubleshooting and it seems one of the valves won't open. There are two electric valves where the LP line comes in. They are both operated by the same 12v wire. If I put 12v to the switches manually I can hear one click and the other not click. Are these valves easy to obtain and/or replace? Why are there two of them? Could there be anything else keeping it from opening. It fired right up just fine in the morning, and just wouldn't that night.

[Rickf1985]

Does your stove light? If it does then I don't know but if it does not then the propane detector has shut of the gas to the whole camper at the tank and will have to be reset at the detector. Are you getting spark to the ignitor? If not then the safety is preventing the valve from opening. Same with if the thermocouple is not seeing flame.

[DaveVA78Chieftain]

Need to know the model number of the unit (e.g. G6A-7E)

[beaverman]

what was the outside temp and is there any moisture in the valves?, those valves are operated by solenoids similar to a gas dryer, any moisture between the solenoid and the valve arm can freeze in mid 20's or lower temps, have seen this a couple times in rigs during Elk season here when temps drop in the teens, have also seen propane regulators freeze in mid 20's or lower ambient air temps.

[DRMousseau]

A Model number is certainly helpful. The following is jus a generalization of somewhat newer systems with electronic ignition.

If system is firing up, but fails to maintain for more than a few moments, then flame sensor has failed or flame is improperly adjusted. An improper flame will not trigger flame sensor adequately and system will shut down. A corroded or failed flame sensor will also shut system down. Make sure sensor, connections and grounds are clean and solid. Controller boards and electronics can and do fail. Make sure board is clean and free of corrosion.

If system is failing to ignite, the common problem is usually a failing/failed igniter. Corrosion and buildup on the igniter can cause a weak spark or none at all. On some, momentarily shutting off power to the water heater will reset the start-up and ignition cycle, if it doesn't do so automatically as some do. My system switch has an indicator light that comes on when the last cycle failed and the system has shut down. It remains on, and the system down, until the switch is shut off a few seconds, and turned back on to reset. If the reset system still fails to ignite, then check for proper ignitor spark.

If spark is present, and no ignition occurs,.... then a valve could be suspect. Gas pressure has to be within a certain range on many for valve operation. Again, a model number is helpful. Too low, like when running out,... and valve will not open. Too high, like when a new propane tank is opened or supply is jus turned on,... then valve will stay closed. High pressure can be released to normal by turning on and lighting a stove burner a few moments. Primary valve will open when in the specified pressure range. Then reset water heater switch for secondary valve and ignition cycle. I have a gauge behind my stove top, that shows system pressure is present from main supply. A "green zone" show the range needed for proper appliance operation. The indicator is often above this zone when gas supply is first turned on. Nothing will work but the stove top,... turning on a burner will drop pressure to the "green range". Furnace, water heater and other ignitor appliances (fridge?) will then operate as they should. Gauge also shows when I am "out of gas", that main supply valve is off, OR main regulator has failed. It also helps to determine if a leak is present somewhere in the system, when pressure cannot be maintained when shutting of main valve and all appliances. A pretty handy and useful item of safety!

If pressure is properly present, and spark is adequate for ignition, and system still fails to ignite,... then appliance valves may be suspect OR gas orifice in burner may be plugged. NOW,... your gonna be doing some disassembly to determine how far gas is moving thru system. Loosen line into valve and check for pressure before valve. If present (and it should be if main supply is on and lines are clear), re-tighten and then loosen line after valve and check for pressure. If present (and it should be if appliance valve is good), re-tighten and then check burner orifice for obstruction. Remove orifice to clean and to verify pressure at orifice is present.

Icing of regulator valves CAN occur. This is not internal system icing, but EXTERNAL icing that occurs on the "relief" side of the valve diaphragm. Make sure the proper regulator is used, are mounted correctly and that moisture and water can drain from relief vent which should always be facing down. Using a vertical regulator in a horizontal manner, or vise versa,... is jus ASKING for trouble.

[shortbus]

I'll see if I can figure out the model number. There is a fair bit of rust around and the labels are pretty faded. LP seems fine, fridge, stove, oven and furnace are working just fine. Water heater was working perfect until it wasn't. Unit sparks just fine, just no gas getting to the flame tube, like I said, one valve clicks and the other doesn't, I'm fairly confident this is the issue. Icing was surely a fear, the failure happened at some lower temps, 20-15 degrees or so, but I don't know how I would have gotten moisture in the LP system and not noticed it anywhere else, and the valve is still not working and I am back in 50 degrees now.

[shortbus]

Atwood C6A-4E


I actually have an older Allegro that I was going to attempt to get up to par, but I have since pretty much declared it just a pile of parts now. While it's water heater is a bit different it had almost the same electric LP valve setup. I snatched it off and hit the terminals with 12v. It does the opposite of mine, the outer one clicks and the inner one doesn't. It's pretty corroded up so I haven't tried to take it apart, but should it be possible to put the working electric valve off this other assembly onto the other one to make a unit with both electric valves working? Can you find these valves anywhere by themselves? It seems parts for a water heater so old are pretty hard to come by.

[Rickf1985]

You need to find out the purpose of these valves before you starting swapping parts! There may well be a reason that one opens and the other does not. Gas is not something to play with when you are guessing at the controls and modifying things.
I suggest you read through this before doing anything else.
The second link appears to show two gas solenoid valves in parallel that are tied into the high limit switch. This may be what you have. Are the solenoids you are playing with gas valves?

http://manuals.adventurerv.net/Atwood-Water-Heater-Service.pdf

http://oldbounders.com/1986_bounder/Atwood%20Water%20Heater/Atwood%20Water%20Heater%20MPD%2093756.pdf

[shortbus]

Correction, G6A-4E. Faded label, totally looked like a "C". Yep, the electric valves labeled as gas solenoid valves are exactly what I'm talking about.

[DaveVA78Chieftain]

As far as the gas valve itself, the P/N is 93870
http://www.adventurerv.net/atwood-dsi-water-heater-gas-control-valve-93844-93870-p-28659.html

However this stuff can be expensive so you need to troubleshoot IAW the manual before throwing parts at it.

[Rickf1985]

Check your valve that is not working and make sure it has a good ground, the ground path may have corroded.

[shortbus]

Both valves share the same ground. When I hot-wired them one clicks and one doesn't. Ground seems to be good. Trust me, I know to always check the grounds.

[Rickf1985]

Seems like you got it covered, try the one from the other heater. Switch the two and that way you don't have an open line on the other heater.

[Oz]

You know... we have these manuals in our Member Area? That was the purpose of going through all the time and effort to create it, so members don't have to wait to get reference links and bounce all over the internet looking for them.


Full or Life membership saves a LOT of time and effort...

[shortbus]

Just wanted to update my thread here. I bought the valve that Dave linked to, found it on amazon though. Installed it and the unit fired right up and works great again. That was indeed all I needed. Thanks guys.

[M & J]

And thanks for the feedback on the fix.