nosey...I mean noisy hot water heater

riverfever

NAXJA Forum User
Yesterday morning and this morning at around 0640, the hot water heater's been making noise. Never heard it during the week and I'm always up moving at that time. Little 411:

This is an A.O. Smith Pro Max model heater. I'm not positive but I think it was installed in 2005. This is a 38 gallon unit. This is my third home and it's the first where 2 people couldn't shower (in succession...not together) without the second person having to move quickly or run out of hot water. I suppose we could just shower together but I'm not sure that guests would approve. Since we moved in almost 2 years ago, we always wondered if there was something wrong with the heater or the plumbing just b/c of the seemingly lack of hot water. The noise that it's now making may be what plumbers refer to as "water hammer". I think it sounds like a woodpecker drilling on metal. The noise lasts for a second or two at most. It started out making more noise this morning than yesterday. I did reset the pilot light and haven't heard the noise since. I do not believe the light was out (didn't check prior to resetting) because I showered after I got home from a ride yesterday early evening and had hot water.

Anyone know anything about hot water heaters?
 
I assume it's gas because you mentioned a pilot light...

Around here, a hammering water heater usually means mineral deposits on the bottom of the tank (lime around here). That would jive with the lack of recovery time.

What temp do you have it set to?

Ron
 
RTicUL8 said:

That thing went into orbit! Good thing it's not directly below my bed.

Ron...yes...I have gas. So does the water heater. I considered the deposits and flushing the heater out. The t stat is set on max as that helped out a bit with our running out of hot water issues.

Frank...thanks for the digits. I'll be calling soon.
 
Flush it. There is valve on the bottom of the tank you can hook a garden hose upto. You can run hose to a drain or outside. Once you hook the hose up turn valve until water come out. Do not turn supply off to the tank. New water coming in will flush the crap out. Turn off the pilot before you start and run hot water down to cooler temp so you don't burn yourself. They say deposits build up in the bottom and water under the desopits turn into steam making the noise you hear. Good luck.
 
I work at a plumbing wholesaler (Parker Winnelson). We sell AO Smith heaters. Give me a call - 6:30 to 4, M-F. 303-617-8430 ask for Steve. If you can give me the serial #, I can figure out the age, and warranty status.
 
Water hammer as I call it only happens when you shut off a faucet and the moving water is stopped and makes the pipe bang against a floor joist or wall stud. Sometimes the pipe just makes the noise itself. What you are hearing is the build up minerals or some contaminates in the bottom of the water heater.

You may get some relief by flushing it. Just don't drain it into a toilet. Temperature changes can crack/break the bowl.

Stang5lgt posted the way to flush the tank. I wouldn't turn the pilot off, just the main burner. So long as the buildup can fit through the drain valve this will help, but many times the buildup is too large to flush put. But it's worth a try.

The lack of enough hot water may or may not have anything to do with the noise. It could be the dip tube. There is a tube inside the water heater that should deliver the cold water to the bottom of the heater, forcing the hot water out the top. If this tube failed the cold water flows across the top of the heater, leaving some of the hot water "trapped" in the bottom of the heater. There is no easy way to check this tube. I don't really know about AO Smith, but State water heaters of that age had a real problem with this tube.

One way you can find out how much hot water you are getting out of your tank is to time how long it takes to fill a 5 gallon bucket with only hot water. Then divide how long it takes to run out of hot water by how long it took to run five gallons of water.

You can also call me if you need any more advice.
Daryl
620 338 5700
 
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River -

One way to check if it is your diptube is to check your aerators. Unthread them from your faucets (pull your shower heads, too). If they're packed up with white or bluish deposits, probably your diptube has distingrated.

Diptube remans will melt (plastic). Mineral deposits won't. I have diptubes at the shop. Run you about 7 bucks.

Steve
 
JEONLYEP said:
Good call Steve....

Nice tip with trying to melt the partials to see what they are.

Just don't blame me if you get caught melting "crystals" in a bent spoon, with your lighter, all alone, in your bathroom.:eek:
 
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