Atwood water heater won't light

[Kirk W]

8 hours ago, coachmac9 said:

checked the voltage at the lead going out to the ignitor and there was nothing but that was expected since there was no "click" to hear or spark to see..

The voltage to the ignition probe is quite high but very brief and so is difficult to measure.  Here is the troubleshooting section from the manual. 

Quote

NO SPARK AND NO GAS
No voltage --------------------------------------------------------Correct power supply - minimum 10.5 VDC
Dirty edge connector on circuit board--------------------------Clean edge connector
Defective thermal cut-off ----------------------------------------Replace thermal cut-off
Defective ON/OFF switch ----------------------------------------Replace switch
Defective circuit board--------------------------------------------Replace circuit board
Defective thermostat----------------------------------------------Replace thermostat

 

Pay particular attention to the procedure on page 21 of that service manual. Anything that interrupts the 12V power will prevent the firing of the spark but the fact that you are getting the light in the switch eliminates a lack of that power. Power to that light comes from the circuit board, so we know that it has power and should mean that the ECO is also passing power but it would not hurt to use your meter to verify that by checking the voltage as you trace to and then through both sets of thermostats. It is always a good idea to remove and reseat all power connections since your water heater has airflow through it when you travel and that air can also carry both dirt and moisture. It only takes a moment to pull each plug and put it back, two or three times just to be sure. Pay particular attention to the lead that goes to that spark probe. 

You could also check for power to the gas valve and if you put your hand on it and have someone turn the water heater on you should be able to feel it open but my experience shows that you may not hear it open. An additional test that I perform when troubleshooting a failure to ignite is to use one of the long butane lighter for lighting a barbeque to see if that lights the propane. They are made of plastic so won't shock you and if you have it burning when the valve opens, you should see the propane light, even if the flame isn't detected and the gas turns back off after 3 attempts. 

It would not be a bad idea to try replacing the ignitor assembly as they can be difficult to troubleshoot and you can get one for about $35. It will come as an assembly with the probe and the lead attached. I have never seen one supplied without that high voltage lead. (I wouldn't buy it if I did). If you buy one, use care as there are several different versions available. Since the probe that supplies the spark also detects the burning propane and sends back a signal to the circuit board to indicate the propane is burning, it doesn't take much to prevent that signal as it is in microvolts. I also always replace the probe if I am replacing the circuit board as they have a shorter lifespan and cost very little. If you do replace that circuit board, I suggest the use of one from Dinosaur Electronics as I have found them better than those from Atwood, they cost less (about half) and have a longer warranty. Of all those that I have used, I have never had one fail. 

[oldjohnt]

GREAT Info from Kirk, looks like he and I and the manual are ALL on the same page. To simplify and summarize, If there's adequate voltage getting TO the board  VIA the switch and t stat and limit switches and the ribbon edge connector (no resistive connections),,,,,,,,,,,,The gas valve should open (easy to feel and/or hear it, test by jumping 12 volts to it and/or check its continuity),,,,,,,,,,,,,,,,,The boards HV coil should begin throwing its spark (try a jumper to verify its producing high voltage),,,,,,,,,,,,,,The HV cable should carry voltage to the Ignitor Tip (check cable and ceramic and tip for hairline cracks or carbon traces and insure a good ground) and it should spark to ignite the gas.

IF there's adequate board voltage (via switch and t stat and limtts)  then you have to see if no fire is the result of 1) The gas valve isn't opening or 2)  The Ignitor Tip isnt firing to ignite the gas or 3) NEITHER is working

IF NEITHER the gas valve is opening ORRRRRRRRRRRR  the boards HV coil itself (IE independent from any HV cable or ignitor tip issues) isn't producing HV to jump a spark and there's adequate board voltage THE BOARD COULD BE BAD.

NOTE One problem in testing voltages at certain locations when you're looking for bad/loose/resistive connections, is there's NO I x R Voltage Drop UNLESS CURRENT IS FLOWING (IE a load is present). You may want to just check and verify the connections and grounds and clean up and polish and re attach.

NOTE  The no fire indicator lamp doesn't take as much current as the rest of the control board, there could still be a bad/resistive connection.

NOTE If the boards HV coil is producing HV for the spark and the cable is good Ive still had the ceramic ignitor tips fail EVEN IF THEY LOOK GOOD TO THE EYE.

NOTE Ive had units fail to light because the ignitor tips gap distance was too small or large

HOWEVER if you're not getting EITHER gas valve OR HV sparking, then its a low voltage or connections or grounds or t stat or limits  or finally yes even a bad board  

LET US KNOW WHAT YOU FIND

GO BY THE MANUAL VERSUS MY SUGGESTIONS IF THERES A DIFFERENCE !!!!!!!!!!!!!!!!!!!!! I'm NOT there and ONLY speaking in general from experience with boards you can get to and perform the tests above.................

 

Best wishes, keep safe and God Bless

John T

 

[ALLOY]

Kirk & John T   This is a good read on troubleshooting a heater.

On another forum I read that rust from the heater exchange can foul the propane jet.

 

[oldjohnt]

1 hour ago, J-T said:

Kirk & John T   This is a good read on troubleshooting a heater.

On another forum I read that rust from the heater exchange can foul the propane jet.

At least twice a year I clean and blow out the heat exchange tube and all the gas inlet and air piping (similar in the fridge n furnace).  I ALWAYS  get some rust n soot. BEFORE however I close off where the LP Gas flows so the rust n soot cant get in. Preventive maintenance is so necessary in those darn RV's and even top of the line units are just as vulnerable. 

John T  ONLY a few more days till we turn over keys to the farm and were OUTA HERE................RV is stuffed to the gills

[coachmac9]

Thanks for all the great info guys, I'm sure thete will be others that will be helped with this info!!! And congrats on selling the house and your adventure that wil soon start!!!

Here's a small update...I worked late yesterday but got home early enough to do some poking around today. I wanted to make sure I was getting the correct voltage coming in to the circuit board so I checked it at a junction before it gets to the board and all is good. Then I unplugged the connector (3 wire connector) at the board and checked, same thing, 12 volts coming in...then when I plugged the connector back in to the board it made a clunk...no spark down stream at the igniter and no more clunks from the board...also no voltage below the board...then the rains came so my detective work stopped there...I did have time to unplug the connection and plug it back in several times...same thing...on click or clunk and that was it.

[Kirk W]

8 hours ago, J-T said:

On another forum I read that rust from the heater exchange can foul the propane jet.

• While it can do so, it really isn't that common on water heaters like it is for refrigerators. With your water heater if you just judiciously use a shop vacuum to suction out any dirt and foreign materials from the opening of the burner tube and air shutter are usually ample to take care of this. I have heard many stories of cleaning the gas jet, but in my experience, more people make their problems worse in doing that than fix anything.
• You can see the burner tube and the opening of the burner area in this picture. If you remove the igniter probe it leaves you plenty of room for the vacuum. The air shutter is the slotted area that can usually be adjusted. Unless you have some reason to do so, it is usually not necessary to adjust it. If you use a vacuum you are far less likely to create problems from getting things in the way of the gas jet. I only use compressed air as a last resort. 

[oldjohnt]

12 hours ago, coachmac9 said:

And congrats on selling the house and your adventure that wil soon start!!!

Thanks coachmac, Closing is in two hours, hope I don't break down lol. We bought the farm in 78 and built the new home in 79, it was our dream and we raised our family here, gonna be tough to walk out the door, but we don't need all the acreage and huge home and upkeep anymore. The time has come, its part of the cycle of life. We have "half timed" for 10 years now full time till we buy our "last" home, before assisted living or nursing home or the cemetery............. 

 

 Best wishes

 John T

12 hours ago, coachmac9 said:

when I plugged the connector back in to the board it made a clunk

 Its important to know if the "clunk" was the gas valve opening???????????? You ought to be able to feel it !!!!!!! Same (clunk) sound if you jumped 12 volts to the gas valve ????? and you would smell some gas ............If it did open but no HV sparky, then its time to check the boards HV coil to see if its causing a spark if a temporary jumper wire to 1/8" to metal gap is attached. That checks for spark at the boards HV coil itself independent from any HV cable or Ignitor tip or grounding problems. If the HV coil is okay then you check for problems in the HV cable and the ignitor tip and grounds and gaps etc as I described above. Once more, if there's adequate voltage (under load) at the board input but no sounds or  gas valve opening nor sparky, I suspect a grounding or board (bad solder joint or strip ???) or still possibly a resistive connection problem.

NOTE if the gas valve opens and holds open (requires adequate voltage and current), then voltage and power to the board itself and its ground must be okay which can rule out "some" of the related issues above. 

John T 

Edited October 4, 2017 by oldjohnt

[Kirk W]

42 minutes ago, oldjohnt said:

Thanks coachmac, Closing is in two hours, hope I don't break down lol. We bought the farm in 78 and built the new home in 79, it was our dream and we raised our family here, gonna be tough to walk out the door, but we don't need all the acreage and huge home and upkeep anymore. The time has come, its part of the cycle of life. We have "half timed" for 10 years now full time till we buy our "last" home, before assisted living or nursing home or the cemetery............. 

At risk of hijacking the thread, I'll offer a brief comment. We were more nomadic than you so had far fewer ties to the last house before fulltime life began. We left the family home after the last child went into the Army but before retirement so that made that part less difficult. Now that we are back to part-time we have come to realize that this may not be our last stop as we are starting to think of a change to no more home-owner responsibility. It is always good to have some rough ideas of what will come next but keep them flexible. 

[coachmac9]

John, definitely was not the gas valve and no gas smell...it was more of just a click and it was at the board...nothing down stream from there...and it would do it once every time I plugged the board back in...but nothing down at the gas valve.

 

 

Edited October 4, 2017 by coachmac9

[Tcwndsr]

I seem to have solved my problem with the water heater, it has been working normally for the past week. The last thing I did was clean the ground and re tighten. I also adjusted the position of the new igniter tip closer to the end of the burner tube. Thanks for all the help and suggestions, it was more frustrating than difficult but following all the tips here should get most heaters up and running again.

[oldjohnt]

6 hours ago, coachmac9 said:

John, definitely was not the gas valve and no gas smell...it was more of just a click and it was at the board...nothing down stream from there...and it would do it once every time I plugged the board back in...but nothing down at the gas valve.

 Its sounding like EITHER the board is bad OR ELSE there's still a weak resistive voltage dropping connection (or ground) allowing low power board components or indicator lights to work but NOT enough voltage and current to operate the gas valve and/or HV ignitor coil. This assumes the switch and t stat and limit switches are all good with no bad connections and good 12 volt source voltage  

Id check to see if the gas valve operates if you manually temporarily jump 12 volts to it??? If so but not via the normal board function I'm back to the above.

John T

7 hours ago, Kirk Wood said:

We were more nomadic than you so had far fewer ties to the last house before fulltime life began.

 Thanks Kirk, we DO have emotional ties to the homeplace where we raised our family, but its too late now, we closed this morning !! Still hope to meet up someday.

 John T

 

[coachmac9]

The final chapter to our hot water saga...I hope!! I took the control board out and began searching for a replacement. To my shock the one that I needed ranged in price from 220 to 250 bucks!!!!

The biggest problem I had with that(besides the money) was that I was dealing with a 16 year old water heater and all the parts that I DON'T replace are still old and I'm not 100 percent sure this part would fix it...I looked at just replacing the whole water heater and the cost was around 400 bucks, so no savings there, and then I remembered that the previous owners had installed a Camco Hot Rod to make the water heater electric also. They told me that it just worked for a short while and then started throwing a breaker...so I got a wiring diagram from Camco and started checking their install...sure enough they had not wired it properly and fried the element in the tank which was causing a direct short and throwing the breaker!!

12 bucks for a new element, about 20 minutes of re-wiring and it worked like a charm!!!! ANDDDDD the best part of the story is my wife bought me tickets to the NASCAR race in Ft. Worth with the money we saved!!!!! WIN/WIN for me!!!! 

Thanks so much for all the ideas and assistance from everybody!! This is a great forum!!

Edited October 13, 2017 by coachmac9

[Tcwndsr]

UPDATE: After a week or so my heater went back to the same intermittent mis-firing. I went through all the connections and adjustments again without much improvement. In the meantime, I discovered my converter was bad and had run down the batteries. I am wondering if low voltage on the batteries couldn't provide enough juice to get a nice spark at the water heater even though my 12V lights and accessories were working normally. Since replacing the converter the water heater has been flawless with immediate ignition whenever I turn the switch on. Thoughts?

[oldjohnt]

19 hours ago, Tcwndsr said:

I am wondering if low voltage on the batteries couldn't provide enough juice to get a nice spark at the water heater even though my 12V lights and accessories were working normally. Since replacing the converter the water heater has been flawless with immediate ignition whenever I turn the switch on. Thoughts?

 I think I shared this earlier, but once I was on the phone with Dinosaur Electronics who manufacture replacement circuit boards and when troubleshooting an ignition problem I was asked to verify voltage at the boards input when the technician lectured me on now I needed to be using a quality DC voltmeter as an accurate reading was necessary and a few tenths too low could make a difference.

 I cant say from here what your problem was but Dinosaur insisted low voltage at the board could be problematic.

 Thanks for the feedback, congratulations on getting it working..........Now if it fails again we will start all over lol

John T  Moochdocking at relatives still in Indiana, starting for Texas tomorrow

Edited October 24, 2017 by oldjohnt

[Kirk W]

4 hours ago, Tcwndsr said:

I am wondering if low voltage on the batteries couldn't provide enough juice to get a nice spark at the water heater even though my 12V lights and accessories were working normally.

While it is possible, I doubt that it is probable and it would be pretty difficult to prove if true. I believe that you did replace the ignition probe so at this point I would suspect the circuit board if the ECO & heat limiter is in good condition. 

[Craigory]

I have the same issue. It starts and heats, then it stops and tries to relight. I hear the click click click three times and it goes to limp mode with a barely audible whine. The gas valve seems to crack open fine initially, but it’s not called for on the relight. Is that because the t-stat or overtemp is bad?

[Craigory]

PS I already bought a new module and that didn’t fix it. If I turn the remote Off and on, it usually starts up, but sometimes I need to wait a bit.

[Kirk W]

2 hours ago, Craigory said:

PS I already bought a new module and that didn’t fix it.

Welcome to the Escapee forums! While don't say the make or model of water heater that you have, they work very nearly the same and your symptoms sound like a problem with the ignition probe. Have you replaced it? There are more than one version and they do need to be for the make (Atwood or Suburban) as well. Here is a picture of what it looks like. 

                              

Some of them have 3 prongs while others have only 2. There a number of differences so make sure that you get the proper one. They are usually available from any RV parts seller. 

 

[Craigory]

Found it to be the thermostat after doping it out a little more. When it tried to relight after running up to temp, it couldn’t. That told me the thermostat was calling for more while the overtemp said nope. That locked out the board until I cycled the remote switch. Thanks for you answers 

[Earl]

Atwood GC10A-4E LIGHTS, BUT WON'T STAY LIT. TRIES 3 TIMES THEN INDICATES A FAULT. ELECTRIC WORKS OK, BUT HAS ALWAYS INDICATED A FAULT AT THE END OF THE HEATING CYCLE, IN BOTH LP AND ELECTRIC MODES.

[Kirk W]

15 hours ago, Earl said:

Atwood GC10A-4E LIGHTS, BUT WON'T STAY LIT.

Welcome to the Escapee forums, Earl.

You say that it lights but will not stay lit, but also that it tries 3 times and then goes into lock-out. With an Atwood water heater it is normal for it to make 3 attempts to ignite the gas and then lock out if doesn't detect that the gas is burning. If you are telling us that it does ignite but tries 2 more times and shuts off, that is an indication that it is not detecting the heat from the burning gas and so shuts off the gas for safety. The vast majority of the time, that is caused by the ignition probe needing to be replaced. The one that you need will look about like the picture in my previous post. 

It is possible that the problem is something else, but this is by far the most likely for your symptoms. You may also find it helpful to download a copy of the service manual. 

Atwood water heaters (1mb)

[Craigory]

Thanks for the reply! I fixed it the next day. It needed a thermostat which makes complete sense. It would run up and over the normal temp until it hit the overtemp limit which closes the gas supply valve. The T-stat says it still wants more heat so the igniter tried three times to start with no gas supply which puts it into limp mode until you cycle the remote switch. Like a $6 part.

[Kirk W]

4 hours ago, Craigory said:

Thanks for the reply!

My last post was in reply to Earl who tagged on your thread. I don't believe that he has been back since I responded.