High pitched faint noise from water heater

[Desert RVers]

I searched the forums and could not find any that are related to our issue.
Our new TT water heater makes a high pitched but faint noise when turned on to electric for heating the water. Is this normal? I had another issue with the water being luke warm. Another member's post on too hot of water helped me resolve the water temp by closing the bypass valve (it was fully opened from the factory). But, the high pitched noise I've noticed for several days now. Don't know how long its been noisy. Once the water heater recovers, the noise stops.
Does any one else know of a fix for the noise? Should we only heat water with the propane?
We plan on taking the trailer in for a small list of warranty repairs after we return home next month. If the noise is not a critical issue, I'll have the dealer look at that as well. I love this forum and it has already given us a wealth of information, so I thought I would check here first.

[mike837go]

Yes, my new Atwood does that too. I expect it is the 12VDC relay that controls the 120VAC that actually heats the water.


It may also be the high volts supply for the spark to light the propane that is not flowing (electric on selected).


Personally, I haven't investigated it because I prefer using propane for hot water (much faster recovery time).


If you want, open the outdoor cover and gain access to the back of the water heater while it is heating the water on 120VAC. And try and listen to exactly where the noise is coming from.

[Camping Couple]

It's the control circuit making the noise. It's normal.

[Desert RVers]

Thanks mike837go & Camping Couple! Good to know it's normal. It only happens when heating water with electric. It doesn't make the noise on propane. We use the electric for the most part so that we don't use the propane. The recovery time on the electric is not a problem for us. On the occasion that we can't wait, then I'll turn on the propane side for quicker recovery. Thanks again!

[Camping Couple]

Originally Posted by Desert RVers

Thanks mike837go & Camping Couple! Good to know it's normal. It only happens when heating water with electric. It doesn't make the noise on propane. We use the electric for the most part so that we don't use the propane. The recovery time on the electric is not a problem for us. On the occasion that we can't wait, then I'll turn on the propane side for quicker recovery. Thanks again!

You betcha! We do the same thing regarding the electric and propane. Good luck!

Mark

[SkyBound]

An added piece of info on this topic - this noise is from the relay only and not the heating element itself. My water heater was making this noise with the electric switch ON, but the main AC breaker was OFF meaning no electricity to the element.

[tslarson]

The high pitched squeal comes from the circuit board itself (maybe the relay is on the circuit board, I never looked). It makes the noise both on electric and gas, but much harder to hear on gas with the burner lit. Our water heater is right under my daughters bunk, and the noise on our heater seemed extra loud and would wake her up at night. We just had to remember to switch the heater off at night, but it was a pain in the butt to remember.
I found that if I removed the 4 attaching screws from the circuit board and pulled the board away from the tank the noise would be much quieter. The tank was acting like a speaker and amplifying the sound. My solution to quieting down the sound was to put 4 big blobs of silicone on the heater where the screws hold on the board, then install the board using the screws but only tighten the screws enough to hold the board in place and squish the silicone a bit. Wait 24 hours and remove the screws. Now the board is held in place with the silicone, and no screws to transmit the sound to the tank. This has reduced the noise by about 75%.