Strange noise from water heater

[cdigger67]

Hearing a strange noise from our water heater when hot water is running. 2018 Outback 330 RL. I'm thinking some kind of check valve in the system?

[flybouy]

Originally Posted by cdigger67

Hearing a strange noise from our water heater when hot water is running. 2018 Outback 330 RL. I'm thinking some kind of check valve in the system?

City water or fresh water pump source? Has the system been purged of all air? Has there been any recent work done on the water system i.e. changed the anode or changed the pump, etc.?

[JRTJH]

Are you talking about a "hum" or such type noise that happens ONLY when a hot water faucet is turned on and water is being used? Or are you talking about a "hum" or such type noise that happens when the electric heating element is turned on and goes away when the water is hot and the thermostat shuts off the heating element? Or are you talking about some other type of noise?

I've heard several electric heating elements that for some reason, tend to "vibrate when they are energized. Sometimes removing and reinstalling them will stop the noise, sometimes that makes it worse and replacing the element stops the noise.

There is a "one way valve" in the water heater "hot water outlet". The purpose is to prevent hot water from "migrating back into the water heater" and is a part of the "winterizing bypass system".

While it's possible for minerals to deposit on that valve and cause it to vibrate or "hum" when trying to open, I've only heard a few. Usually you'll be able to feel the vibrations if you put your fingers on the water heater outlet in the back of the water heater. If it's vibrating, that might be the source of your noise.

Then there's almost always an occasional "bang or clank" from the metal tank as it expands. These are typical of any metal object as it warms up and the metal expands.

Otherwise, if one of these is not what you're hearing, maybe a better description would help identify the source.

[cdigger67]

Originally Posted by flybouy

City water or fresh water pump source? Has the system been purged of all air? Has there been any recent work done on the water system i.e. changed the anode or changed the pump, etc.?

City water, nothing done to system. Has been working fine for months. We are fulltimers.

[cdigger67]

Originally Posted by JRTJH

Are you talking about a "hum" or such type noise that happens ONLY when a hot water faucet is turned on and water is being used? Or are you talking about a "hum" or such type noise that happens when the electric heating element is turned on and goes away when the water is hot and the thermostat shuts off the heating element? Or are you talking about some other type of noise?

I've heard several electric heating elements that for some reason, tend to "vibrate when they are energized. Sometimes removing and reinstalling them will stop the noise, sometimes that makes it worse and replacing the element stops the noise.

There is a "one way valve" in the water heater "hot water outlet". The purpose is to prevent hot water from "migrating back into the water heater" and is a part of the "winterizing bypass system".

While it's possible for minerals to deposit on that valve and cause it to vibrate or "hum" when trying to open, I've only heard a few. Usually you'll be able to feel the vibrations if you put your fingers on the water heater outlet in the back of the water heater. If it's vibrating, that might be the source of your noise.

Then there's almost always an occasional "bang or clank" from the metal tank as it expands. These are typical of any metal object as it warms up and the metal expands.

Otherwise, if one of these is not what you're hearing, maybe a better description would help identify the source.

It is a humming noise that happens any time a hot water faucet etc. is opened. Doesn't matter if the electric water heater is on or off. No banging noises. No access to back of w/h without removing it.

[JRTJH]

Originally Posted by cdigger67

It is a humming noise that happens any time a hot water faucet etc. is opened. Doesn't matter if the electric water heater is on or off. No banging noises. No access to back of w/h without removing it.

There's "always access to the back of the water heater" without removing it. In your trailer, I believe the water heater is in the forward roadside corner. Access is obtained by removing the "false closet bottom" in the wardrobe above the water heater. If you look, you'll find several screws holding that access panel in place. Once the panel is removed, you'll see the "plumbing runs and electrical connections for the water heater. The top plumbing connection is the hot water supply line. The "one way valve" is located there.

[cdigger67]

Originally Posted by JRTJH

There's "always access to the back of the water heater" without removing it. In your trailer, I believe the water heater is in the forward roadside corner. Access is obtained by removing the "false closet bottom" in the wardrobe above the water heater. If you look, you'll find several screws holding that access panel in place. Once the panel is removed, you'll see the "plumbing runs and electrical connections for the water heater. The top plumbing connection is the hot water supply line. The "one way valve" is located there.

Thank you so much JRTJH. If I tear into it, that will really help me in my quest to fix it. I had this type noise in my 40' Diesel pusher several years ago. It was very difficult to get to but I did get it done. Thanks again.