I bought a house 2 years ago, and for the last few months every time someone uses the shower the water heater makes a bubbling/boiling sound.

I just looked at the ID tag, and its a natural gas heater, State Water Heaters brand, 40 gallon manufactured in 1991. Its giving us no trouble, other than the odd bubbling sound when the burner first kicks on during heavy hot water usage.

I couple months ago, the first time i heard the bubbling sound, i connected a hose to the bottom drain cock attempting to flush any sediment, but the water came out perfectly clear with no sediment.

Sounds like you have sediment build up in the bottom of the tank. It gets heated up first when the water heater starts warming the tank up. The sediment traps air/water in pockets at the bottom of the tank. These get heated first and boil up through the sediment making noise. A 1991 water heater (27 years) has certainly given you decent service, so it’s soon to be time to change it out. Better you do it on your own scheduled time than waiting til it decides to fail on a cold night when you need a hot shower.

Generally, they leak around that age. If there isn't any water in the drain pan under the unit, it isn't from the tank. I'd be curious if the gas line has condensation in it that you hear bubbling when the gas flows.

15-20 years

27 years out of a HWH is pretty good. There is a procedure to flush a HWH to get sediment out:

https://www.artofmanliness.com...ur-hot-water-heater/

However, with an old heater it could loosen scale that could cause a leak.

A benefit with a new HWH is it will be more efficient(hotter water, and less gas consumed).

I wouldn't have one older than 10 years. Worked in the property restoration/water damage industry for a few years. Seemed like 12 years was the most common age they started failing.

quote:

How long is a home water heater supposed to last?

a day after the warranty expires.

The sound is pretty loud, it can be heard throughout the house. It sounds like pretty large bubbles forming in the bottom of the tank and floating up to the top.

Theres no leaks whatsoever.

Since attaching a hose to the bottom and opening the draing cock produces no discolored water or sediment whatsoever, i was worried about maybe layers of rust inside the tank, on the bottom opposite the burner flam perhaps creating the same symptoms as sediment. Like, water between rust layers overheating and creating steam bubbles.

My concern is that the water heaters operating pressure, according to the label is 150psi, if the rust is deep enough to compromise the integrity of the tank, the possibility of the tank bursting and injuring anyone nearby.

Is that a legitimate concern with a water heater?

Likely very improbable, but i dont wanna be this guy!
https://youtu.be/iQK6McNdyXE

I may pick up a new one today. What are the better brands?

quote:

Originally posted by Sgt Neutron:
27 years out of a HWH is pretty good. There is a procedure to flush a HWH to get sediment out:

https://www.artofmanliness.com...ur-hot-water-heater/

However, with an old heater it could loosen scale that could cause a leak.

A benefit with a new HWH is it will be more efficient(hotter water, and less gas consumed).

I followed this process and got no sediment at all.

Ken,
I'd start shopping for a good deal on a new one if I were you...
Best regards.

I replaced a 1991 Sears Roebuck water heater last fall in a rental unit last fall. It was still working but I didn't want to deal with it on an emergency basis in the middle of winter. The 10 year old one in my house started leaking last fall and I replaced it.

Mine are 20 years old this year. They are starting to degrade noticeably.

Considering new electrics or gas tankless as we speak.

The big question is where is it installed and what will it destroy if it goes??
If it is in a garage or unfinished basement let it run unless the noise is too bad.
We bought our house and it was 13 years old. I replaced the water heater because the basement was fully finished and the basement carpet was brand new.
Did not cost much with the rebate from the gas company. Kind of wish I would have sprung for tankless but cost for venting would have been high.

quote:

Originally posted by doublesharp:

quote:

How long is a home water heater supposed to last?

a day after the warranty expires.

And you're out of town.

My last that failed was in attic as are all in TX, and it missed that window by 3 days. I was outside and heard a weird dripping on side of house where I'd never heard before. Lo, a PVC pipe was dripping water. Upstairs find the drain pan nearly full. We were leaving for a 3-week absence, and would have returned to water running out under the front door.

OTOH, we have an original one still in our cabin in rural AL, installed circa 1963. It's one of those counter-height boxes sitting in the kitchen, we've replaced the element once and that's it. Remarkable. Probably tempting fate to mention it.

When I was in high school (mid 1960's) a water heater a few houses away blew up in the middle of the night. It woke me up. I had my current water heater replaced in 2002. No leaks, never been drained and works just fine, but after watching a couple of videos just now, I wonder how much longer it will last. Last water heater started leaking under the linoleum and destroyed the floor in my laundry room. Current one got installed to code and has a pan under it with a drain to the outside of the house.

Replace it ASAP. 28 years is exceptional. Probly double the life expectancy.

A few years ago My heater was pushing all kinds of brown hunk into the tub every time we’d draw a bath for the kids so I had it replaced. We bought the house 10 years ago and the plumber who installed it said it was from 96 so at least 20 years old when I replaced it. He said if you get 10-15 years out it you got your money’s worth.

quote:

Originally posted by Ken226:

My concern is that the water heaters operating pressure, according to the label is 150psi, if the rust is deep enough to compromise the integrity of the tank, the possibility of the tank bursting and injuring anyone nearby.

Almost every water heater will make some noise. It may be worse in winter with the colder water coming in.

Its actual operating pressure is only ~equal to your current water pressure.
150psi is just the rated MAXIMUM working pressure the tank is rated for, and they are tested to double that. IIRC.

Old rusted water heaters don't explode or burst. Not saying it would be impossible, just extremely unlikely unless improperly installed. Virtually all just spring a leak at the weakest point. In 18 years in the business I never saw one "burst" and we averaged replacing about one a week.
Given a 100% safety margin it would take at a minimum 300psi to break a NEW tank... a properly installed tank should vent any extreme excess pressure via the relief valve long before the tank is compromised, even an old one.

The danger is in the water damage from a leak. I have seen leaks from a tiny seep up to a few gallons a minute, some I have seen leak in excess of what the drain pan piping could carry away. And I have seen pans overflow because the drain is plugged with years of debris that collected in the pan.

As someone else suggested, budget and plan for a replacement if in a area where water damage is a concern...

quote:

Originally posted by dbgeek:
I'd be curious if the gas line has condensation in it that you hear bubbling when the gas flows.

I'm curious, what's your background to come up with such a wild idea?

My gas heater in TEXAS is in the garage (not in the attic) Most I have seen are in garage or house. It is 19 years old and plan on replacing it. Not worried yet. I believe all gas heaters have a a relief valve. Mine does.

12-15 years, but I’d be hesitant to let a modern water heater go past 10 years. Flushing the sediment annually will go a long way to extending the useable age.