Hot water humming noise

[Bbawt]

Our 2017 19 has the Suburban SW6D hot water heater. Today I was getting the trailer set up for the season and checked the anode, filled the fresh water tanks, flushed the system, switched the by-pass levers back to allow the tank to fill, re-flushed the lines and turned on the control panel hot water switch. The unit lights up fine. However, while the switch is on, I'm getting a high pitched hum or whine sound. If I turn the switch off, it stops right away. I've heard that noise can happen with with the electric element but ours is only propane. Anyone have any ideas? Maybe the check valve?

Thanks,
Brian

[rbryan4]

I would look at the check valve, yes. Is the noise affected when you manipulate the valve slightly (without draining water)? If so the whine might be because it's not fully closing.

[rubicon327]

Just for proper nomenclature it sounds like we are talking about the pressure relief valve, not a check valve. I think that is a good start. Let us know if lifting up on it slightly affects the noise.

The trailer is too new to typically need a replacement already and it should be under warranty. This is the part anyhow, Suburban 161157:
http://www.amazon.com/Suburban-16115.../dp/B000BPK7HU

[gbaglo]

And here is the pressure relief valve ( top centre ) closed and open.

[Bbawt]

I tried the pressure relief valve but no luck. Attached is a video where (hopefully) you can hear it.

[StarvingHyena]

Hi Brian,
Here is what I do to find the source of 'strange noises':

Get a dowel of appropriate length ... typically 1/4" diameter or so. Take one end of dowel and place the first joint of your thumb over it and place the other side of said joint in / on ear. Other end can now touch various components and act like a stethoscope and you should be able to hear and trace the source of the wine. The use of thumb is to keep me from jamming the dowel into my eardrum.

The way my hearing is ... especially with high pitched sounds ... my ears alone would try to convince me it was the hitch ball making that noise.

Good luck! That's quite a wine!

Tom

[wetzk]

I suspect it may be from from the fenwal circuit board.
To check you will need to get under the bed and look on the side of the water heater towards the rear. Have someone turn the water heater on and see if the sound is coming from the small box on the side of the water heater. It has a flyback transformer in it and that sounds high enough to be from a flyback.

Edit, it could also be some weird problem involving that board and the gas valve too, but I lean more towards it being on the board itself. If it is either replacing the board should fix it.

[Bbawt]

Originally Posted by StarvingHyena

Hi Brian,
Here is what I do to find the source of 'strange noises':

Get a dowel of appropriate length ... typically 1/4" diameter or so. Take one end of dowel and place the first joint of your thumb over it and place the other side of said joint in / on ear. Other end can now touch various components and act like a stethoscope and you should be able to hear and trace the source of the wine. The use of thumb is to keep me from jamming the dowel into my eardrum.

The way my hearing is ... especially with high pitched sounds ... my ears alone would try to convince me it was the hitch ball making that noise.

Good luck! That's quite a wine!

Tom

Thanks for the tip - I figured out it was the circuit board, but I'll have to try this dowel trick!

[Bbawt]

Originally Posted by wetzk

I suspect it may be from from the fenwal circuit board.
To check you will need to get under the bed and look on the side of the water heater towards the rear. Have someone turn the water heater on and see if the sound is coming from the small box on the side of the water heater. It has a flyback transformer in it and that sounds high enough to be from a flyback.

Edit, it could also be some weird problem involving that board and the gas valve too, but I lean more towards it being on the board itself. If it is either replacing the board should fix it.

You guessed right! I crawled in under the bed and sure enough the noise is coming from the circuit board (see photo). I'll contact Escape and see about getting it replaced.

[tractors1]

Originally Posted by Bbawt

Thanks for the tip - I figured out it was the circuit board, but I'll have to try this dowel trick!

That's another version of the mechanics stethoscope - put a big screwdriver on a car/tractor motor and the handle in your ear. Works surprisingly well!

[Vermilye]

Originally Posted by tractors1

That's another version of the mechanics stethoscope - put a big screwdriver on a car/tractor motor and the handle in your ear. Works surprisingly well!

Just be careful poking a metal screwdriver around electrical parts. Great for engines, but a dowel is probably safer around a water heater...

[Oldtimer]

Little tip from my maintenance days one can still use the mechanics stethoscope in tight electrical spaces take a small diameter dowl drill aa hole down the middle just a tad larger than the probe n slide it over the probe works just fine

[StarvingHyena]

Wonder what they would do on the Red Green Show?

Tom

[Oldtimer]

He would just get out his duct tape n keep putting it on the area till he didn’t hear it anymore

[titanizer]

And it looks waaaaay koooool too.

[richardr]

Originally Posted by Bbawt

You guessed right! I crawled in under the bed and sure enough the noise is coming from the circuit board (see photo). I'll contact Escape and see about getting it replaced.

I need a little help with the photo orientation and the exact location of the little circuit board. From what direction is the photo taken and which way is up?

[wetzk]

Originally Posted by richardr

I need a little help with the photo orientation and the exact location of the little circuit board. From what direction is the photo taken and which way is up?

If it helps, here is a picture I took earlier of ours. I lifted the mattress and removed the plywood to access the area for another project.

[wetzk]

Originally Posted by Bbawt

You guessed right! I crawled in under the bed and sure enough the noise is coming from the circuit board (see photo). I'll contact Escape and see about getting it replaced.

Which board did yours have in it? Mine had the Fenwal that had the ignitor part in it fail. I ended up buying one rather than make several trips to a repair place.

[Bbawt]

Originally Posted by richardr

I need a little help with the photo orientation and the exact location of the little circuit board. From what direction is the photo taken and which way is up?

Sorry about the photo orientation...the phone showed it upright, then when I posted it came up sideways. Left is top and the board is just to the left of the tank.

[Bbawt]

Originally Posted by wetzk

If it helps, here is a picture I took earlier of ours. I lifted the mattress and removed the plywood to access the area for another project.

A much better photo than mine! Thanks.