Atwood Water Heater Repairs, model GH6-6E

ClydesdaleKevin · July 18, 2012, 12:26 AM

A while ago our 23 year old Atwood water heater, model GH6-6E was giving us some problems...it is an early model Direct Spark Ignition style, and until recently has been working flawlessly.

So first it started overheating, causing water to pour out of the pressure relief valve...which would pour down on the wiring and cause the water heater to go out. I replaced the 1/2 pipe theaded pressure relief valve as a precaution (a cheap part), and then went ahead and replaced the ECO and Thermostat switch, also cheap parts and easy to reinstall...even comes with the black foam self adhesive cover. At the recommendation of Atwood's tech support, I also cleaned the scale out of the tank, which they said could build up over the years and shield the thermostat from the true tank temp.

Cleaning the scale out of the tank is easy. You shut off your water supply, then remove the pressure relief valve and the drain plug. Obviously let the water cool down first! Then you replace the drain plug, and using a funnel, pour 4 gallons of white vinegar into the tank through the relief valve hole. Top it off with water, which won't take much, and let it sit for 24 hours. After 24 hours, remove the drain plug and let it all drain out...you'll see all KINDS of white particulate matter pour out! And the white vinegar will now look milky. Put a cone shaped water nozzle on a garden hose, and put it in the pressure relief hole and turn it on...just let it run until the water runs clear...it will take a while, and you'll see a lot MORE white crud and scale come out of the tank. Now put teflon tape on the pipe threads of the drain plug and install it, and do the same for the pressure relief valve, and tighten them down. Turn back on your water supply, and then turn one of your faucets in the RV on all the way to hot to fill the tank with water. Once all the air spurts out, the tank is full and you can turn on the water heater again.

I did the flushing before installing the new ECO and Thermostat switches so they wouldn't get all wet...and then dried all the wiring off with my wife's hair blow dryer. I turned on the switch inside the RV and she fired right up, didn't overheat, and was fine for a while. Total cost of the above repairs was 15 bucks for the ECO and Thermostat switch kit, 15 bucks for the new pressure relief valve, and about 4 bucks for all the vinegar...for a grand total of 34 bucks.

Now some have said that my next step was overkill and unnecessary, but I did it anyways. I bought an aftermarket drain plug with a 4 inch anode rod attached, to help keep the scale away. Apparently Atwood lines their aluminum tanks with a substantially thick anode material, but heck, it was only 10 bucks, the old plug was knurled from someone using the wrong tool, and I figure at 23 years old some of that anode material has to be wearing away, so I went ahead and did it anyways for peace of mind. Brings the total to 44 bucks.

All was well for a month or so, but then the water heater started acting wonky. It would light and stay lit for a while...and then would unexpectedly shut down for no apparent reason. It would only do it once in a while, then got more frequent, and then wouldn't fire up at all.

I went outside and had Patti turn on the switch, and I heard a whiny sputter from the ignition control board, which is an old style DSI (Direct Spark Ignition) circuit board behind a white plastic cover....and no spark at all on the peizo electric elements. I took it off and shook out an old mud wasp nest, but at first didn't see anything amiss with the circuitry...no burn marks on the board, etc. Then Patti took it inside to wash the cover, and that is when she noticed the melted section and burn marks on the cover. I looked and aligned it with the board, and yep, it was the great big capacitor that sends the spark voltage! A close look at the capacitor revealed signs of overheating, so the control board was toast!

So I started looking at my options. There were a few sellers that had old style boards, which aren't made anymore. They were around 240 bucks!

Atwood makes a universal control board, but you have to take the wiring plug apart, install spade terminals, and then carefully drill new mounting holes in the sheet metal, without damaging the tank beneath, to mount it. And they cost from 112 buck to 120 bucks.

Then Dave, the Tech Support guru here on the forum, gave me his great-as-usual advice and told me to look into Dinosaur Electronics...makers of circuit boards for obsolete or older appliances.

Thanks Dave!

I did some shopping around and found a Dinosaur Electronics UIB-S universal ignitor board for 64 bucks, and that was with expedited shipping, so I'll have it here by Saturday! Its the post version, 4.25 in length, just like the one I have, so it will be a direct fit with no modifications, not even to the wiring! Plug and play since its the exact configuration, even where the plug slides on. I'll have to remove one jumper so it doesn't have the 3-try start and just direct starts, which they recommend the removal of for water heaters and refrigerators.

Since the Dinosaur board is updated from the original with LED indicator lights and even a 5 amp spade fuse, and since the cover is all melty and burned, I also ordered a clear cover made for it, also by Dinosaur Electronics, for only another 8 bucks...SWEET!

3 year warranty on the thing too, which is pretty good for an electronic part!

So for 116 bucks my water heater will now probably last another 23 years! We are never in freezing temps so the chance of the water tank ever cracking is minimal. All that is left that can break on it is the electronic propane control valve and the starter elements, but they are also cheap parts.

WAY cheaper than buying and installing a new water heater!

I'll let you all know when the new parts come in how it all works out.

The GH6-6E is obviously a darn fine water heater, since ours has lasted for over 23 years, and is definitely worth saving!

Kev

tiinytina · July 18, 2012, 08:42 PM

Kev - we had same issues with ours... I had replaced thermostat, ignitor, and had the board tested (bad)...Looked all over for a replacement board but like you said $250... we ended up replacing the whole thing but.. the PO had also cross threaded the inlet valve at some point and no matter what we did the thing always leaked... and obviously had as the floor was rotted out under it... glad you found a cheaper fix...
Tina

ClydesdaleKevin · July 19, 2012, 07:41 AM

Thanks Tina! The previous owner of ours did a hack job on the plumbing behind the water heater, which I already replaced and fixed, so thankfully he didn't cross thread anything!

The new control board should be here by Saturday, so I'll let you all know how it works!

Kev

ClydesdaleKevin · July 21, 2012, 09:04 AM

Okay, now I have a quick wiring question for the Dinosaur Electronics UIB S ignitor board. It arrived yesterday, but doesn't fit in the stock cover, so I'll have to wait until the new clear cover made by Dinosaur arrives, which should be here on Monday or Tuesday.

Also turns out I should have ordered the Large board afterall, but its not a big deal...it just means I have to carefully drill 2 new lower holes in the sheetmetal of the outer tank cover a little higher...the electronics of both boards are exactly the same, just the size is different in length. At least I ordered the small cover, which will fit the small board!

Okay, onto my wiring question. On the original DSI Old Style Circuit Board, there is a plug of wires that plug into the board...and its the same male side, marked the same, on the new Dinosaur board. So that is the easy part. Both boards have the plug style for the spark ingitor wire coming off of the capacitor. So that is the same. There is a resistor that has to be cut off on the new board for use in water heaters and fridges, but its well marked and self explanatory. BUT...There is also an extra black wire that comes out of the old board, and plugs into a secondary port on the old style ignitor, which we are still using. There is no extra wire coming off the new board.

I did a little research, and while the 2 wire ignitor looks like it has 2 ignitors, only the one on the left is the actual ignitor...the one on the right is some sort of sensor?, and the electrode its attached to protrudes past the other ignitor into the burner tube. Apparently its some sort of obsolete sensor? In any case, they don't even sell the 2 wire ignitor anymore, and Atwood says it can be replaced with the new style one wire one electrode model. So, what do I do with that extra wire? Just cut it off? If I'm looking at all this correctly, if I simply plug the one wire onto the capacitor, it should work, since the electrode side is the same as the new models. Anyone know what this extra wire did? It went from the right side "electrode" (which apparently isn't an electrode, and its only my blind guess that it was a sensor of some kind) and into the old circuit board, apparently soldered to a hole near the base of the old capacitor. It can't be a ground obviously, since there is already an electrode post to ground that the left side electrode sparks against...and that right side "electrode" is also suspended in a ceramic insulator. Another question: Is it going to effect how my inside water heater button works? With the old board, when you hit the inside button a green LED light comes on...and will start flashing red if the heater fails to ignite. Do you think it will still do the same, or does that now-obsolete wire have anything to do with its function?

And finally, before I cut that jumper wire...are we absolutely sure we cut that jumper wire/resistor off the new board? Once I cut it there is no going back!

Thanks!

Kev

DaveVA78Chieftain · July 21, 2012, 03:34 PM

When Direct Spark Igntion (DSI) control boards were initially designed they had a 3 probe design (Remote Sense). One probe was ground; One probe was HV Ignition; One probe was a flame sensor (same type of sensor approach used on a pilot model gas valve with a thermocouple). Later models used a 2 wire design where the ignitor and sensor probe where combined onto one lead (Local Sense).

You should have the following connections listed on the UIB S Post board

Power
NC
Valve
Sensor
Ground
Ignitor Post

Referring to the center schematic (Front Mount ECO/Thermostat like your 6H6-6E) on page 24 of http://bryantrv.com/docs2/docs/atwoodwaterheater.pdf the control board connections are:

Power - Brown wire coming from Thermostat
NC - Blue Wire to Ignition Fail Light
Valve - Red wire going to Emergency Cutoff (ECO) switch which supplies the gas valve
Sensor - White wire to the sensor post on the ignitor (sparker)
Ground - Green Wire
Ignitor Post - Black (?) wire to the ignitor post on the ignitor (sparker)

The sparker is grounded by it's attaching screws.

Dave

Update - Opps I almost goofed. The UIB S is a Local not Remote Sense board. So, the "Sensor - White wire to the sensor post on the ignitor (sparker)" is not used. The ignitor post wire supplies the HV spark then is used to monitor the flame (2 wire version). This essentiall changes the design to reflect the bottom drawing on page 24.

Dave

ClydesdaleKevin · July 22, 2012, 08:58 AM

Yep...right after my last post I did a lot of research and also found that the wire to the sensor electrode is not needed...even says so on the Dinosaur Electronics website under FAQ. Apparently I'm not the first one to ask what to do with that extra wire...lol! Not entirely sure my sparker will work...might have to buy a one wire sparker...but I'll know for sure once I set it all up and turn it on.

So my tracking numbers for the cover say that it arrived in Tuxedo Park, NY yesterday, so I would have had it all fixed and ready to go yesterday...but this post office doesn't deliver on weekends...so I'll have to wait until Monday.

As far as cutting the resistor off the board, I'm pretty sure that its the right thing to do...

We'll see!

Kev

DaveVA78Chieftain · July 22, 2012, 09:39 AM

By resistor I take it you are reffering to the "Instant Fire" option.
http://www.dinosaurelectronics.com/Instructions/UIB_S_inst.pdf
http://www.dinosaurelectronics.com/Single_try.htm (left side pic for your board)

Jumper installed - 20 sec between retry cycles. Furnace has a blower so it can evacuate any residule LP Gas quickly

Jumper Removed - 60 sec between retry cycles. No blower in Water heater so needs longer for allow residule gas to dissipate.

Cover is only to prevent the board from being exposed to water (leak, splashing, washing the rig). You can test the setup without the cover.

Dave

ClydesdaleKevin · July 23, 2012, 08:53 AM

Thanks Dave! I don't want to even test it without the cover since they are predicting rain off and on all week...and when it rains here, it can rain! Anyhow, the cover should arrive at the office today, so this afternoon, if all goes well, we'll have hot water again...SWEET!

Kev

ClydesdaleKevin · July 24, 2012, 06:51 AM

Alright! We have hot water again...SWEET! The cover arrived around 4pm, so I installed it as soon as I had it in my hands.

The Dinosaur Electronics UIB S Rev.10 Post board works perfectly, and she lit right up, faster than ever!

I had to make a couple of minor modifications. First, because I mistakenly ordered the small board instead of the large (same electronics and function, only the size is different), I had to mark and drill 2 more screw holes in the outside sheetmetal of the water heater (To keep from drilling too deep and possibly damaging the aluminum water tank, I set the depth of the drill bit by wrapping it with Gorilla Tape...stuff sticks to anything). Next, because I am using it in a water heater, I had to carefully remove the jumper resistor on the new board. Then the original screws were too long...the new board with the new cover has a much lower profile than the old board...so I simply used shorter screws. Once I plugged it in and screwed it down with the cover in place, I had to make one more modification...Where the sparker wire plugs onto the post that comes out of the big capacitor on the board, I had to strip back some of the wire boot...the post doesn't stick out of the cover nearly as far as the original, and the wire boot, which looks like a spark plug wire boot, wouldn't fit down all the way onto the post until I removed some of the boot...just enough so that it was on all the way, which allowed the rest of the boot to act as a seal for the cover.

Then it was time to test it out. Patti hit the switch inside while I watched from outside. The board's LED went to Green, meaning it had power, then immediately to Red, meaning it had opened up the propane valve....click click WHOOSH....we had ignition! Now that I knew the sparker would work without the redundant wire, I clipped that wire off so it wasn't just hanging there.

Once the water heater reached temp, it shut down, and the LED went back to green. I ran the hot water in the sink to make sure it cycled properly, and yep, light went red, and whoosh, instant fire...SWEET!

The only thing I have left to do now is fill out the 3 year warranty card and mail it in!

3 years is a pretty darn good warranty for an electronic part, especially a circuit board!

Kev

rnrphoto98 · January 15, 2013, 08:02 PM

If you dont mind, what site did you find the board on? I need to get one of theses myself.

Thanks

Rob

ClydesdaleKevin · January 15, 2013, 09:18 PM

I found it, and the cover, on eBay. Just type in Dinosaur Electronics UIB in the search window. It should also bring up the cover. You might have to play around with the wording, but there are a lot of them on eBay. Price shop too, since the prices vary a LOT!

Kev

rnrphoto98 · January 24, 2013, 10:45 PM

Thanks for the INFO. I will check it out.

Rob

eddie · January 25, 2013, 12:23 AM

Fun success story. I love it when a plan comes together!!!