Water heater clattering

[Tashajo]

We are living in our TT full time and run our water heater off electric. Yesterday it started making a strange noise after I turned it on, and now it's making an awful clattering combined with a loud running water noise when it runs. The water still gets hot and I've not noticed any issues so far but the noise. It was running fine two days ago and yesterday morning I had to turn it off to do a little maintenance and when I turned it back on it was making the noise. Any ideas? I've already turned it off and back on and it still does it.

[Wild_Bill_888]

If a new heating element is severely corroded after a few weeks, you probably have electrical problems causing a current to flow through the water between the element and tank. Test the voltage between the tank and the frame with the heating element energized and de energized, use alternating current and direct current scales. All reading should be 0.

De-energize the entire system, AC and DC them check the resistance from tank to frame, it should be 0 ohms, if not, install a ground wire from tank to the frame, use 12 gauge or bigger wire.

If a circuit breaker blows when you re energize the system, look for a hot wire on that circuit rubbing against the tank.

Also check the voltage on the element when heating to make sure you are not putting 220 volts on a 110 volt element.

[Old-Biscuit]

Tashajo wrote:
We just bought the camper in July and are dealing with the previous owners neglect. We flushed out the tank and replaced the element. Now to see if it works. It was very badly corroded.

Do you have a Suburban Water Heater?

Badly corroded electric element suggests lack of an anode rod AND lack of any routine flushing of tank

[Tashajo]

We just bought the camper in July and are dealing with the previous owners neglect. We flushed out the tank and replaced the element. Now to see if it works. It was very badly corroded.

[dougrainer]

1. Replacing elements 2 or 3 times in 4 months is extreme. They last for YEARS
2. Since you have replaced the elements and it appears, NO noise until you did this indicates your elements are probably not OEM quality AND correct Length. Where did you get your elements? Local HD or Lowes/Ace Hardware? If so, odds are they are LONGER than required and maybe touching the back of the tank interior pick up tube and that is causing the noise on Heat Cycle.
3. You need to remove the Drain plug and do a complete flush of the inner tank.
4. I would get the Atwood or Suburban(whichever brand you have) OEM element and compare to the ones you have installed. Doug

[rhagfo]

dougrainer wrote:

Tashajo wrote:
The water themperature hasn't changed at all. And this would be the third element put in since July if I have to replace it. Im going to drain and flush the tank out and hopefully that fixes it. If not I'll get another new element. Last time it went out it never made a noise just stopped working.

If you have replaced 3 elements in 4 months, you have other problems. Possibly too high voltage to the RV or you do indeed need to flush the water heater tank. Elements will last years, unless you are buying cheap aftermarket elements or elements that are NOT built and the CORRECT length for an RV water Heater. LENGTH maybe your problem. Maybe you have one that is TOO LONG and it is rubbing on the back end of the Tank. Doug

^^^^ This, or you are turning on the WH before it is full of water, and burning out the elements, but that doesen't explain the noise issue.

[rhagfo]

Tashajo wrote:
Would the check valve make noise when it's heating or just when the water is running? I can run water through and it makes no noise till it starts heating again, then it sounds like an angry coffee pot.

Ours and another Host, both only made noise while drawing water.

[dougrainer]

Tashajo wrote:
The water themperature hasn't changed at all. And this would be the third element put in since July if I have to replace it. Im going to drain and flush the tank out and hopefully that fixes it. If not I'll get another new element. Last time it went out it never made a noise just stopped working.

If you have replaced 3 elements in 4 months, you have other problems. Possibly too high voltage to the RV or you do indeed need to flush the water heater tank. Elements will last years, unless you are buying cheap aftermarket elements or elements that are NOT built and the CORRECT length for an RV water Heater. LENGTH maybe your problem. Maybe you have one that is TOO LONG and it is rubbing on the back end of the Tank. Doug

[2112]

Our electric WH did this in our old house. It made a crackling sound when heating. Almost like popcorn popping. It told me it was time to flush the WH. We had hard well water. Calcium deposits would build up on the element, flake off and build up on the bottom.

[Tashajo]

The water themperature hasn't changed at all. And this would be the third element put in since July if I have to replace it. Im going to drain and flush the tank out and hopefully that fixes it. If not I'll get another new element. Last time it went out it never made a noise just stopped working.

[Tashajo]

Would the check valve make noise when it's heating or just when the water is running? I can run water through and it makes no noise till it starts heating again, then it sounds like an angry coffee pot.

[D_E_Bishop]

Wild Bill is most likely correct regarding hot spots. With a gas heater, the rattle is a sure sign there is too much sediment in the bottom of a WH and needs either a through flushing or replacement. The rattle is caused by boiling without circulation of the water.

In an electric WH, it is the sound of a hot spot on the element and it should be replaced. Cleaning is usually not an option, how would you clean it, scrapping or rubbing it off with an abrasive can damage the surface and cause another even worse hot spot.

$15 for an element is a cheap try for fixing the noise.

The small bubbles in water are suspended and will normally join together or dissipate to the surface in one heating cycle. If you had that happening every time you used hot water and the tank refilled, there is some abnormality in the plumbing, shore or internally.

[Wild_Bill_888]

A few possibilities come to mind.

1 An unusually high concentration of air dissolved in the water, creating noise as the Heat releases the air in the form of bubbles.

2 The heating element is developing a defect that causes a hotspot which causes water to boil on the surface of the element. The collapsing steam bubbles make the noise.

3 Mineral deposits on the heating element are creating hotspots that result in Steam bubbles which makes the noise as they collapse. You could remove the heating element and clean it but my inclination would be to order a replacement heating element and just wait and see what happens.

The hot water discharge pipe is generally mounted high on the hot water tank. That would vent a large amount of air trapped in the tank, and keep the heating element submerged fully.

Has the temperature of the hot water increased recently? An increase in the thermostat setting could result in boiling sounds.

[drsteve]

rhagfo wrote:

Put in by pass and the noise will likely stop,
If it does then the check valve on the hot water outlet port is likely bad, just went through this ourselfs. This is NOT the pressure relief valve, but the brass nipple on the hot water outlet port of the WH.

Yup.

[old_guy]

there has to be a air pocket on the top of the water in the tank. it could be the air is missing and the water is banging onthe top of the tank when heating. drain the tank and start over and get the air back into the tank. be sure to turn off the electric before draining