Water Heater Popping Noise

[05cavalier]

Hell everyone

Last Friday I had a PRV installed on my house as it didn't currently have one and the water pressure was through the roof. Almost immediately after that (later that night) my water heater starting making popping noises when heating water. Never heard it before, but now I hear it every time someone takes a shower or you adjust the thermostat higher. It sounds like popcorn, with maybe the occasional rock sound. The heater is a Rheem 22v40f1 that's 8-9 years old.

I tried to flush it for about 5 minutes (kept the cold water supply on and just connected a hose and let it drain for a while). Crystal clear water. I didn't collect any to see if there was small bits of sediment in it, but this water looked so clean you could drink it. After this, the noise persisted so I moved on to draining it.

I shut it off, turned off the cold water supply, opened a faucet in my house, and drained it all out from the water heater. It only took 30-45 seconds which I was expecting much longer. I turned on the cold water supply expecting to see sediment come out now, and nothing. Still crystal clear water. I let it run for maybe 2-3 minutes before closing the drain valve. I turned the heater back on and again it started making the noise. You can hear the water start to boil with no loud noises, but I'd say near the end of the cycle is when the noises start.

Again this never happened once before the PRV install, and now it happens every time. I don't know why the 2 would be related, but since the water is crystal clear I'm not ruling anything out prematurely.

Any suggestions for next steps?

 

[Reach4]

Never heard it before, but now I hear it every time someone takes a shower or you adjust the thermostat higher. It sounds like popcorn, with maybe the occasional rock sound. The heater is a Rheem 22v40f1 that's 8-9 years old.

That is a natural gas WH. I know you know that, but I had to look it up.

I suspect it may have been making popping noise while the flame was bringing up cold water to hot before, but you were not down there listening for it.

If you flush again in the future, I would let the WH drain, and turn on the water full for a few seconds. You want turbulance. Drain again. Repeat a few times.

 

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[05cavalier]

That is a natural gas WH.

I suspect it was making popping noise while the flame was bringing up cold water to hot before, but you were not down there listening for it.

The water heater is in the garage which is very close to the living room. It pops so loud now you can hear it throughout the house and you can actually feel it in the floor if you're on the first floor. It's always possible I just didn't notice it before, but now it definitely has my attention. You're saying this is normal for a gas water heater?

 

[Reach4]

Let's get some other opinions, but I think some popping is normal. See if somebody notices it without having it pointed out to them.

 

[MACPLUMB]

You have little pieces of lime pockets build up on the center flue pipe when the heater comes on these pockets turn to steam
then pop off causing the popping noise you hear,
with the higher water pressure this kept lime pockets closed off

 

[05cavalier]

You have little pieces of lime pockets build up on the center flue pipe when the heater comes on these pockets turn to steam
then pop off causing the popping noise you hear,
with the higher water pressure this kept lime pockets closed off

So what would your solution be? Just to clean the flute?

 

[Reach4]

Hmmm. Look at #10 on this one"
https://terrylove.com/forums/index.php?threads/popping-noise-not-sediment.29814/

 

[Jadnashua]

The older the WH, the more likely you'll hear those noises. A water softener will reduce the minerals in the water and slow their deposits inside of the WH, but will only reduce them very slowly if they already exist.

 

[05cavalier]

The older the WH, the more likely you'll hear those noises. A water softener will reduce the minerals in the water and slow their deposits inside of the WH, but will only reduce them very slowly if they already exist.

That makes sense, but I guess my main issue is that the water came out crystal clear, but also seemingly drained in under 30 seconds and that just shouldn't happen - it should take a couple minutes. I'm wondering if something blocked the drain valve, then when I turned the cold water back on became dislodged but still stayed in the tank. I'm going to try draining and flushing again just to check.

I guess the main questions is other than being annoying, is this dangerous? The water heater is from 08 so it's coming up on 10 years old. I'm thinking it may be more worthwhile to plan on just replacing it when it fails than spend possibly hundreds on servicing it, but I don't want to cause any other issues. Is there a chance the sediment gets kicked up and makes it into the main house plumbing and gets stuck/causes issues?

EDIT: So I was able to drain the entire thing. I opened the pressure release valve on the tank and it didn't gush out but it did run dry finally. I let it partially refill and then drained twice more then let it run openly for another 2-3 minutes. This time I did gather some in a bucket each time and there were some small pieces of sediment but no big chunks and really no more than I would expect if I just opened the hose bib on the side of the house. I did notice a sticker on the side claiming this to be a self cleaning unit, which could explain the very small amount of sediment.

It's currently reheating and while it's definitely still noisy, it doesn't seem nearly as bad. At the same time it still isn't to my liking. I guess only time will tell as we all take showers tomorrow. I ran out of daylight tonight so I may need to repeat the process a couple more times next week/weekend but to be honest since there hasn't been much come out and it claims to be self cleaning, I feel like I'm just wasting water and gas at this point which is just flushing money down the drain.

 

[Jadnashua]

While you can get some loose sediment in the tank, the mineral deposits often will literally cake onto the surfaces, and draining won't help in the least. You'll only get the loose stuff out. Plus, there could be a fair amount of essentially rigid stuff in the bottom of the tank that is decreasing the overall capacity and slowing the reheating since it acts like insulation over the burner to the water. There are lots of variables on how long a WH will last, but yours is past the average age when it fails.

When you get a new one, consider replacing the drain valve with a ball valve that would allow you to stick a rod through it when opened to help break up any deposits. Or, do as most people do, and just replace it when it reaches that age when it starts giving issues. The vast majority of people never drain their tanks, and they tend to last as long. The sediment doesn't always come out, and rodding it can end up breaking the lining, making it rust faster. You probably also never changed the anode rod, and it is no longer protecting anything. FWIW, opening the T&P valve, when it hasn't been operated in years, can often allow it to leak. If yours closed and sealed, consider yourself lucky. Ideally, you check the thing every 6-12 months. They do wear out, but often, can last the life of the tank before it starts to leak.

 

[05cavalier]

While you can get some loose sediment in the tank, the mineral deposits often will literally cake onto the surfaces, and draining won't help in the least. You'll only get the loose stuff out. Plus, there could be a fair amount of essentially rigid stuff in the bottom of the tank that is decreasing the overall capacity and slowing the reheating since it acts like insulation over the burner to the water. There are lots of variables on how long a WH will last, but yours is past the average age when it fails.

When you get a new one, consider replacing the drain valve with a ball valve that would allow you to stick a rod through it when opened to help break up any deposits. Or, do as most people do, and just replace it when it reaches that age when it starts giving issues. The vast majority of people never drain their tanks, and they tend to last as long. The sediment doesn't always come out, and rodding it can end up breaking the lining, making it rust faster. You probably also never changed the anode rod, and it is no longer protecting anything. FWIW, opening the T&P valve, when it hasn't been operated in years, can often allow it to leak. If yours closed and sealed, consider yourself lucky. Ideally, you check the thing every 6-12 months. They do wear out, but often, can last the life of the tank before it starts to leak.

Thanks for the feedback. I just bought the house last year, so I have not done the yearly checks since they were done when I bought the house. I do know a basic checkup was done prior to purchase but other than making sure there were no obvious leaks and that it did heat water, I'm not sure how extensive it was. I'm sure nothing was drained or checked internally, just simply open a hot water faucet and look at the outside. There are no stickers indicating service dates (not even sure they do that), just a sticker indicating installation date of 2008.

The heater itself seems to work fairly well so I'm not in a big rush to replace it yet so long as there won't be any other damage to the house's plumbing such as some of that sediment getting loose and getting sucked into the main plumbing.

Included with the house was a 1 year home warranty so I may see what cost of service and replacement is through them and see if it's worth replacing before it runs out or if I should just let it run until it does die and then replace it.

 

[Dana]

For the record, did an expansion tank (properly pre-charged to the intended house side pressure) get installed somewhere on the house side of the PRV when the PRV was installed?

 

[05cavalier]

For the record, did an expansion tank (properly pre-charged to the intended house side pressure) get installed somewhere on the house side of the PRV when the PRV was installed?

There was already an expansion tank installed directly above the water heater. I am unsure what pressure it is at, but the pressure was not checked or adjusted when the PRV valve was installed. The pressure on the main line (prior to PRV install) was at 115 psi (roughly 4pm on a Tuesday) when I do not recall hearing any noises. After the PRV install water pressure was set to 50psi (4pm on Friday).

 

[Dana]

The expansion tank charge really needs to be adjusted to match the system pressure to be fully functional.

But unless it has failed and is full of water it's probably not related to any new noises in the system.

 

[05cavalier]

The expansion tank charge really needs to be adjusted to match the system pressure to be fully functional.

But unless it has failed and is full of water it's probably not related to any new noises in the system.

I do believe it to be functioning correctly. When the plumber was out to do initial assessment of the high water pressure, he tapped on the tank and it sounded empty. It was a complete after thought by him to change it to a 4 gallon tank instead of 2, but he had no real reasoning for it other than to sell me more services, and even admitted the tank was more than sufficient for me. He didn't seem at all concerned about it causing any issues.

 

[Master Plumber Mark]

Once these things start banging , they never stop... If you are absolutely hell bent on doing something
to the older heater you can drain it totally out and then pour a 3 gallons of vinegar into the unit and let it
set overnight if you can live without hot water for that long...
Very rarely have I seen this done but it is supposed
to eat up the lime in the units....

Flush out the vinegar and refill...
The hot water will probably smell like salad dressing for a while and
IN THEORY is it supposed to work for a time and it will build up again...

They also sell something on line that is supposed to be stronger
than just plain old vinegar... Like CLR .


I wont waste my time with doing this for anyone because its cost and time prohibitive but you can go for it if you so desire.....

the only other thing you can do is just change
the heater if this does not solve the issue...

 

[05cavalier]

Once these things start banging , they never stop... If you are absolutely hell bent on doing something
to the older heater you can drain it totally out and then pour a 3 gallons of vinegar into the unit and let it
set overnight if you can live without hot water for that long...
Very rarely have I seen this done but it is supposed
to eat up the lime in the units....

Flush out the vinegar and refill...
The hot water will probably smell like salad dressing for a while and
IN THEORY is it supposed to work for a time and it will build up again...

They also sell something on line that is supposed to be stronger
than just plain old vinegar... Like CLR .


I wont waste my time with doing this for anyone because its cost and time prohibitive but you can go for it if you so desire.....

the only other thing you can do is just change
the heater if this does not solve the issue...

Thanks for the tips. I had seen the vinegar thing before and saw the mixed results. I keep asking a bunch of questions and my main one keeps getting lost in the mix lol. Other than being annoying, can this cause any other danger such this lime buildup getting into the main plumbing of the house and causing issues?

 

[Master Plumber Mark]

Thanks for the tips. I had seen the vinegar thing before and saw the mixed results. I keep asking a bunch of questions and my main one keeps getting lost in the mix lol. Other than being annoying, can this cause any other danger such this lime buildup getting into the main plumbing of the house and causing issues?

no it wont do anything except lower the efficiency of the water heater...
Many folks dont do anything about
it but dont realize that it can double or tipple the cost of heating the water
some people leave them alone and wait for them to leak never realizing that
they probably paid for the new heater once already in energy losses....

https://s3-media4.fl.yelpcdn.com/bphoto/-aIAW0HhpmndSXV1qw6Lwg/o.jpg

 

[05cavalier]

no it wont do anything except lower the efficiency of the water heater...
Many folks dont do anything about
it but dont realize that it can double or tipple the cost of heating the water
some people leave them alone and wait for them to leak never realizing that
they probably paid for the new heater once already in energy losses....

Definitely makes sense. This "should" be covered under home owners warranty since it is not listed as an issue in my home inspection but I'm sure they'll weasel out of it. Rather than just dump the cash now I'd rather budget for it and replace it in a few months. My gas bill is under $10 including tax and fees right now so if it is losing efficiency it's still far from being toast and no one in the house has noticed performance decrease, just noise.

Thanks for the responses everyone, they were very helpful.

 

[Jadnashua]

Many people only replace a WH once it starts to leak (or has some other catastrophic fault). But, there are sometimes signs that it is approaching its end of life, and it is prudent to at least budget for replacement. Yours is past the average age of failure, but that is just the average.