Water Heater Noise

[MainerBob]

Strange thing - We are parked in an RV park with full hook-ups so we are connected to outside water and elec (sewer too) so our 12 gal Suburban water heater is on electric and has been for almost a week. The water pump is off as is the "gas" switch for the heater.

Yesterday the water heater began to make a noise resembling water flowing through some kind of restriction, or friction. It only happens with the hot water and when I put my hand on the body of the heater, reachable inside the coach, I can feel a subtle vibration. This is not felt when I grasp any of the plastic plumbing to or from the heater. The sound is obviously coming from the heater itself. I have no leaks inside or out and the hot water flow has not changed.

Any ideas what to check or look at or what it might be?

Bob

P.S. We are in Terlingua, TX if any of you are in the area. Also why are we getting this long disclaimer at the end of each message we get?

[Old-Biscuit]

oilslick wrote:
Every RV hot water tank we have had up until our last trailer had an anode rod, thinking someone had installed the wrong drain plug I bought one with the anode on it and stuck it in. When I came to drain the tank after the first season I couldn't get it out the hole, after much work I did manage to get it out and the very small amount of corrosion had swelled it. I returned to the same nylon plug that was installed. Our current trailer also has the nylon plug with no anode. Not ALL water heaters have an anode, of course I know that now.:)

That's correct.......
Atwood (1/2" drain hole with a nylon plug) does NOT use an anode rod (even though they are for sale in the aftermarket). Aluminum alloy tank so no anode rod.

Suburban (3/4" drain hole---drain plug/anode rod combo) DOES use an anode rod due to porcelain lined steel tank....better to sacrifice the anode rod vs the steel tank.

[oilslick]

Every RV hot water tank we have had up until our last trailer had an anode rod, thinking someone had installed the wrong drain plug I bought one with the anode on it and stuck it in. When I came to drain the tank after the first season I couldn't get it out the hole, after much work I did manage to get it out and the very small amount of corrosion had swelled it. I returned to the same nylon plug that was installed. Our current trailer also has the nylon plug with no anode. Not ALL water heaters have an anode, of course I know that now.:)

[Jerry_B]

jetcare wrote:
If it only happens when you are running water out of the hot water tap, it is the check valve located at the back of the water heater on the hot outlet.

Mine did the same thing then finally quit delivering any water from the hot water fawcets. I replaced the brass check valve on the output side of the water heater. Fixed the noise/no flow problem.

[Old-Biscuit]

MainerBob wrote:
This is the OP and I thank all of you for your helpful info. Having shut off the electric and still getting the noise I have concluded that it is the check valve. I have good access to the back of the heater so next time we are someplace with RV parts I will pull it out and replace it. I'll also look at the anode. Right now we're in Terlingua, Texas where they think an extensive assortment of RV supplies is one pack of AquaChem toilet paper. Have a great holiday, y'all.

Bob

Instead of a new check valve that can cause problems again just remove the internals of nipple on WH tank (check valve) and install a shut off valve (1/2" available at any hardware store)......no more check valve problems and easy to isolate hot outlet side when bypassing WH to winterize....IF/when you need to winterize.

Anode rod only used on Suburban Brand. It's there to protect the porcelain lined steel tank from corrosion/deterioration.

[Old-Biscuit]

dbl.post

[MainerBob]

This is the OP and I thank all of you for your helpful info. Having shut off the electric and still getting the noise I have concluded that it is the check valve. I have good access to the back of the heater so next time we are someplace with RV parts I will pull it out and replace it. I'll also look at the anode. Right now we're in Terlingua, Texas where they think an extensive assortment of RV supplies is one pack of AquaChem toilet paper. Have a great holiday, y'all.

Bob

[Dave_H_M]

Well I think the OP has been answered. Vulcaneer did a good job on the isolation issue. So now I got the urge for a hi jack. :B

I am old hinky and paranoid about not putting the anode rod back in the Suburban. However my guess is that if I throw it in the trash, I would never suffer the ill effects of doom and gloom as described. I ran a thread on this eons ago, and there are more than one folk that throw that thing away and camp happily ever after. And yes it has been 14 years and I have not checked the rod in my stick home water heater.

[Old-Biscuit]

aruba5er wrote:
a plumbing contractor to replace an anode rod. You got WAY too much money.DIY or ask some other camper around you. If you have a RV you must know how to fix things or you will be in the poor house in short order. Nuf said. the noise could be the water boiling off the element. Happens all the time in electric heaters at a home. No differance, smaller tank. Some (Attwood) don't have anode rods nor does mine (Surburban) as I took it out in 2007 and installed a 3/4" brass ball valve in it's place. Can blow out the crud in seconds now if needed. Household water heaters have an anode rod and no one would ever think of replacing them. Think about it. Have any on you reading this even thought about it. Be honest now.

Your water heater...your choice.
Hope you disclose this fact to any potential buyers if you sale.
And realize you caused the leaks in your WH tank from choosing not to use an anode rod.

[larry_barnhart]

We have not had a check valve on the water heater for years so I bought one and it makes noise. It sounds like something going around and slows down as the water is turned off.
chevman

[Vulcaneer]

Ok...Aruba. How does any of that help the OP?

Now we all know how smart you are. By the way, I have changed many heater rods in my home water heater. Usually every few years. Honestly.

To the OP...try turning off the electric switch and heating the water with propane. See if that stops the vibration. If it does, that points to the anode rod being an issue.

If you need to drain the water heater, turn it off for a day or so. Then relieve any pressure in the tank by flipping the relief valve. When the pressure is fully relieved, then remove the anode rod and drain the tank. Then the anode rod can be replaced.

If you do not feel comfortable doing this yourself, get someone who knows what they're doing. Those tanks build a LOT of pressure. And that is HOT water. Can be dangerous.

[aruba5er]

a plumbing contractor to replace an anode rod. You got WAY too much money.DIY or ask some other camper around you. If you have a RV you must know how to fix things or you will be in the poor house in short order. Nuf said. the noise could be the water boiling off the element. Happens all the time in electric heaters at a home. No differance, smaller tank. Some (Attwood) don't have anode rods nor does mine (Surburban) as I took it out in 2007 and installed a 3/4" brass ball valve in it's place. Can blow out the crud in seconds now if needed. Household water heaters have an anode rod and no one would ever think of replacing them. Think about it. Have any on you reading this even thought about it. Be honest now.

[fishingbob61]

X2 to eHoefler

[Old-Biscuit]

Johnadam wrote:
If popping noises persist, consult a plumbing contractor regarding replacement of the anode rod in the tank. Anode rods are designed to attract minerals and can deteriorate over time. Ineffective anode rods allow excessive buildup of minerals, leading to popping noises and other problems.Replace a deteriorated anode rod with a collapsible anode rod that allows installation in water heater closets without removing the tank.

RV water heaters that use an anode rod (Suburban Brand ONLY) have the anode rod as part of drain plug.........no professional plumber needed, no removal of tank needed........just remove drain plug/anode rod clean it up with a wire brush, flush water heater tank and re-install drain plug/anode rod.
IF it's a Suburban Brand WH (Atwood Brand nt use anode rods)

No need to replace anode rod until it has deteriorated 75%

[eHoefler]

It is water heating up around the element, perfectly normal. Residential units will also do it.