Hot Water Heater Makes High Pitched Sound when I turn it on

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rejack

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Joined
Apr 15, 2018
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5
Hello,  I am new to this forum.  I have a Atwood GC6AA-10E how water heater.  I was de-winterizing my camper and I am having problems with my hot water heater.  When I turn it on it makes a high pitched sound.  This happens when I turn on the gas and electric.  When I turn on the gas, I can hear it trying to start but it makes an alarm sound while trying to start.  It will try a few times then it does nothing.  When I turn it on electric I can hear it try to turn on but doesn't make any other noises.  I filled the water heater before turning it on.  I released the pressure.  I have done everything I can think of.  Does anyone know what the problem might be?
 
Welcome to The RV forum!

Some whine while the gas is on or lighting is normal, the circuit board uses a small high frequency wave to detect whether or not the flame is on.  It travels between the igniter probe and ground, when a flame is present it changes the resistance of the air.

You may have collected some air in the propane lines while the RV was in storage.  Try lighting a stove burner with a BBQ lighter and see if it catches immediately.  It may just blow air until propane reaches the burner.
 
I had already turned on the stove to make sure the air was out of the lines.  I have figured out some things.  I could not hear the sound once the bed was back together.  You could only hear it outside and only if the it was on electric.  I am not sure if it has always been like that or I just never noticed.  I do believe my starter is bad.  When I light it manually, it is fine. Do you know if it always makes that sound?
 
I have the same heater and the same problem. I thought it was metal parts vibrating but as a previous poster suggested it is the circuit board (confirmed by the dealer). Since I only hear it outside the TT and its not that loud, I've decided to leave it be.
 
I really appreciate the information I have received here.  I think I too will just let it be but I do need to replace the starter.

Thank you

 
Well I just thought I knew what I was doing.  My hot water heater works fine on electric.  When I put it on gas it will not light.  If I light it manually it is fine.  Does this mean it is the starter and if it is does this mean I have to replace the whole starter panel?
 
I don't mean to hijack this thread, but I also have a high pitched whine when my water heater is on, but not coming from the water heater. I have noticed for the entire three years I have owned this coach that whenever the water heater is on, either in propane or electric mode, a high pitched sound emanates from the center speaker of my 5 speaker home theater system. The sound doesn't come out of any of the other speakers and it doesn't seem to make a difference if I'm using gas or electric, so I'm stumped as to what may be causing it. My first thought would be one or both of the speakers wires has lost their insulation but I have no way of tracking that down without tearing the coach apart. And why would the sound be produced if the heater was running on propane? If anyone on this forum has a guess or answer, I'll sure appreciate hearing from you. I assume it won't cause an issue so I just live with it and know when the water heater is working.
 
rejack:


When you turn the water heater on, do you hear the click of the electronic starter? If not, it could be the board, or it could be that the contact between the electrode and the ground is too wide for it to spark, or the contacts are dirty. There is also an article in the Forum Library about spiders spinning webs in that area because they are attracted to the smell of propane. A little cleaning with a small brush and or compressed air may solve that issue.


Frank.
 
It was the board.  Thank goodness it was still under warranty.  Thanks everyone for your help.  This is a great place to get the information I need.
 
John Stephens said:
I don't mean to hijack this thread, but I also have a high pitched whine when my water heater is on, but not coming from the water heater. I have noticed for the entire three years I have owned this coach that whenever the water heater is on, either in propane or electric mode, a high pitched sound emanates from the center speaker of my 5 speaker home theater system. The sound doesn't come out of any of the other speakers and it doesn't seem to make a difference if I'm using gas or electric, so I'm stumped as to what may be causing it. My first thought would be one or both of the speakers wires has lost their insulation but I have no way of tracking that down without tearing the coach apart. And why would the sound be produced if the heater was running on propane? If anyone on this forum has a guess or answer, I'll sure appreciate hearing from you. I assume it won't cause an issue so I just live with it and know when the water heater is working.

John,
I've just run into a very similar problem and suspect that you might not have gotten to a solution for this yet. What I've found is that on my 2014 Winnebago Via, I was getting that whine in a newly installed amplifier in my bedroom. The whine only happened when the Atwood water heater was running - either gas or electric. Listening closely to the water heater's controller board, I hear the exact same tone - a little over 1Khz according to the scope on the audio wires. It looks like the Atwood's control board is injecting a lot of switched-mode power supply noise into the RV's wiring and this is causing a sort of ground loop in the audio. I spent a little bit of time trying to kill the noise at the source (water heater), but the few things I tried didn't help. So, I added a ground loop isolator to the inputs of my new audio amp and this eliminated the noise by 95%, which I'm satisfied with. I'm not sure if your audio system is factory or if you've modified it in some way, but I did notice that even the factory setup in my Via has a ground loop isolator on one of the audio aux inputs into the mid-coach entertainment system - maybe for the same reason. The isolator that I used can be found by searching Best Buy's website for "Metra ground loop isolator" - it was the closest available to me.
Hope this helps with your issue...
 

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Rene T said:
See Reply #8  April 25th 2018. He replaced the board under warrantee and problem solved.

Reply #8 was the OP dealing with the noise coming directly from the water heater controller (not from the audio system) - note that John does NOT hear the noise directly out of the controller like the OP does. I believe that the direct noise is merely a result of the windings of a transformer on the board vibrating from the changing magnetic field during normal operation - mine does that as well and you can literally push on the transformer and quench much of the noise. They put varnish/glue on those windings to suppress any acoustics but it's not always 100% effective. I don't think it's technically a defect for them to make a little noise, and buying a new one may or may not fix it in my opinion. A new one might make the direct noise too, or could start to in a year or two - unless they've sufficiently redesigned the controller or if you buy an aftermarket one that is designed differently. But I suspect that even a brand new (identical version) controller will STILL create the ELECTRICAL noise (as is John's experience, apparently - his makes no direct noise) as its electrical operation would be unchanged. The electrical noise is more a function of the controller's electrical behavior in combination with the way the coach wiring is routed, grounding, etc. There is a chance that Atwood has redesigned the unit due to such complaints, so buying a new one (or an aftermarket one) COULD eliminate the ELECTRICAL noise that John is dealing with, and thus alleviate the need for the ground loop isolator. But a new controller is probably a lot more expensive than a ground loop isolator, and it's a gamble as to whether replacing the controller will fix his issue if buying the same model. If John has made mods to the system already or otherwise isn't afraid to pull these things out and do some debugging (basically unplug RCA's until the noise stops - this can be done to some extent BEFORE ordering the isolator), then trying the ground loop isolator is a cheap and easy thing to do. Similar models are on Amazon/eBay for less than 10 bucks.
 
Via25Q - thanks for the input on this issue. Most of what you discussed went over my head because I'm not an electronics guru. But since this was brought back up, I'll give you some additional info and see if you can further refine your thoughts on the problem.

I wrote this query in April of 2018. In June, I was told by my mechanic that I needed a new water heater. He installed another Atwood, similar to the original other than it doesn't have DSI. The noise persists, even from the new unit.

The sound system in my 2005 Adventurer is original with the exception of a new head deck in the dash to replace the original that was there, and the previous owner installed a new flat screen television. When he did, he connected the tv to the center and front speakers and left the rear disconnected. When the stereo specialist installed the new head deck for me, we looked for the connections to the rear speakers and found one end hidden behind a false wall in the tv cabinet and the other end hanging loose at the system's amplifier underneath the dash. We reconnected each end, using a headphone jack for the output of the tv. This means that there is no 5.1 Dolby, but instead, simply stereo. However, I find it interesting that all speaking (voices) come out of the center speaker, just as in a 5.1 system, while music from commercials will be delivered in stereo through both the front and back speakers. I have no idea if this system is supposed to have actual 5.1 or just a cheap imitation.

The most fascinating thing about the problem with the water heater hum is that it will come out of the center speaker anytime the heater is running, including when the stereo system is shut off. I have heard it when I get up in the morning before turning on the television. But it only comes out the center speaker, not the front, rear or subwoofers.

I don't know if this information will help you narrow down the issue, but any thoughts on the subject will be appreciated. 'thanks for taking the time to read this old post and comment on it.
 
Hey John,
I'm glad my response didn't go unread, and it looks like my suspicions that water heater (controller) replacement would not help your issue were correct. So your description was pretty extensive and it seems to describe a somewhat circular arrangement, which isn't unusual - especially in RV's - and this can be a cause of ground loops. One thing I'm unsure of is: How many TV's are you describing here? Are you per chance willing to scribble up a wiring diagram of your connections? No matter how messy, it would be very helpful. Just make sure to note which end of each wire is an output from a device and what signals are in a given wire (L/R audio, etc).
Hopefully we can get this solved...

But maybe just as important, did the noise start to occur after a certain connection was made, such as with the wire that was found behind the false wall?

Finally, it seems you are tracking down two problems: The noise, and a mystery as to why only certain speakers have certain content - is that true?
 
I don't know how familiar you are with the older units, or how long Winnebago continued to use the same setup they have in this one, but the television in the living room is run through the same amp the dash head deck is wired into with a flip switch on the dash that throws the signal from either the dash deck or television to the speaker system. I have no idea how it is wired because the stereo guy who installed the new deck was the one playing with the amp after we figured out where it was located - in the dash in front of the passenger's seat.

There is no way I could draw you a schematic since I have no working knowledge of the wiring. I appreciate your help and curiosity to get this problem resolved, but there is nothing more that I can tell you. Basic ignorance.
 
No problem - I wasn't sure how much of the wiring you already had apart and were thus familiar with. I am not familiar in detail with any Winnebago's wiring except mine :-[. My last coach was a 94 Allegro with much older equipment. In any case, if the issue bothers you enough, I'd simply recommend that you go trial-and-error with this. If you know that the noise started when a certain wire was added, then I'd start there. This ground-loop stuff can happen even when volumes are set low, so if possible, remove one end of a L/R audio or L/R/Video wire while the system is on and the noise is occurring. If the noise stops, then this is a possible place to insert the ground loop isolator. If your isolator has separate ground connection wires (in addition to the RCA inputs and outputs) like mine does, you don't need to worry about connecting them for the purpose of testing, and you may not need to connect them at all in the end - especially if you don't have a ground nearby - leaving them open could cause a small reduction of stereo separation, but connecting them to ground could actually make your noise worse again. Also, if you find that the noise is reduced by inserting at one end of a cable, it's possible that it would be further improved by instead inserting at the other end of the same cable. I hope this doesn't sound too complex - here's the basic trial-and-error flow:

1) Pick an RCA L/R wire pair
2) Unplug the wire pair
3) Does the noise go away? Yes: Go to step 5, No: Go to step 4
4) Plug the wire back in, choose another wire, and go to step 2
5) Insert the ground loop isolator with it's OUTPUT side toward the equipment INPUT. You won't harm anything by accidentally getting this backward - the performance is just decreased. Leave any extra ground wires unconnected for now.
6) Is the noise still gone? Yes: Go to step 8, No: Go to step 7
7) Remove the isolator, choose another wire, and go to step 2
8) Test the system out with whatever you like to listen to. Is the sound acceptable? Yes: Go to step 10, No: Go to step 9
9) Try connecting the ground wires to the nearest available ground, and also test with the isolator connected at the OTHER end of the same wire. Go to step 11
10) Connect the ground wires to the nearest available ground and leave connected if the noise is still gone. Otherwise leave them taped off.
11) Done - but if the process DECREASED but didn't ELIMINATE the noise, you could need more than one isolator - repeat the process as necessary - I think you get the idea.

Notes:
- The video (yellow) RCA wires should not be involved in this. The ground loop adapter is only for audio, and I don't think you mentioned video noise. But to be thorough, leave any video wire (that's part of a Red/White/Yellow trio) disconnected while testing a wire.
- Once one end of the wire is disconnected, this should reduce or eliminate the noise as much as that wire possibly can. Inserting the isolator will not further reduce the noise - it will ever-so-slightly increase the noise, but hopefully leave it at an acceptable level. Point is that if you get a reduction (but not elimination) of the noise by disconnecting, you can disconnect two or more wires to find a possible combination of wires that need to be isolated, meaning more than one isolator might ultimately be needed.
- Don't forget that when the Atwood water heater reaches temperature, the electrical noise generated by it will stop!

Hope this clarifies a bit!
 
Great explanation, Via25Q!

If I can add one point ... ground loop noise can also be carried on the yellow video line, as it's shield goes to the same places as the audio shields you're isolating with the ground loop isolator.  You may not notice the interference in the picture because audio is much more sensitive to low level interference than video.

If the audio interference goes away when you unplug the yellow video connector (after adding the audio ground loop isolator), there are video ground loop isolators available at reasonable prices, just do a Google search.  You'll have to adapt the BNC in and outs to RCA plugs.

Here's one example:

https://www.amazon.com/Ground-Isolator-HD-TVI-Coaxial-Female/dp/B07QM52HRK/ref=asc_df_B07QM52HRK

https://www.showmecables.com/bnc-female-to-rca-male-adapter

https://www.showmecables.com/bnc-male-to-rca-female-adapter
 
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