AO Smith ProMax Water Heater = Piece of Junk

Date June 8, 2010

Hi All,

First, please forgive all the redundant spellings and overuse of the phrase “AO Smith ProMax” in this article.  I really want the search engines to pick this article up.

I moved into my new home about 4 years ago, and installed in the basement is an AO Smith ProMax hot water heater.  When we purchased the house we didn’t think anything about it.  Hot water heater is a hot water heater huh?  They generally last about 15 years, so didn’t think much about it.

About 7 months ago we woke up to no hot water.  “Oh man, did we pay the gas bill!?!”  Check the stove top .. yep gas is on.  “Oh man, I hope the hot water heater didn’t spring a leak.”  Head to the basement.  No immediate visible damage.  Check the pilot light and it’s out.  I figured maybe a gust of wind or something must have blown it out.  I relight it and go on about my way.

Next morning.  No hot water again.  “Seriously?!”  I check the pilot light and it out again.  Ok, no way it was just a gust of wind.  So I light it again and check back in about 30 minutes.  It’s out again.  I start googling around to see what’s up.

Lots of people immediately tell me it’s the thermocouple went bad on my AO Smith ProMax hotwater heater.  I’m doubtful because the pilot light will actually light and stay lit.  It’s not until sometime later during the actual heating cycle that the flame and pilot light goes out.  If the thermocouple went bad, I don’t think the pilot light would even light.

I post a question on Yahoo Answers, and this super helpful guy tells me there is this screen at the bottom, under the burner assembly that gets clogged up.  Clean the screen, and the problem will go away.  I look, and sure enough on the AO Smith ProMax water heater, there is a mesh screen under the burner assembly.  I later found out this is a flame arrestor.  Anyway, evidently this thing gets clogged up with dust, dirt, particles, whatever, and restricts airflow and causes the burner to go out.

I clean the flame arrestor screen on the AO Smith Promax heater, light the pilot, and sure enough the thing stays lit for about 6 months.

Well, here we are with the SAME problem again only 6 months later.  I light, relight, clean, light, clean, I do everything to make sure that thing is clean.  Day after day after day of no hot water.  Basically it got to the point where I had to re-light the pilot light multiple times a day.  I finally just got in the habit of lighting the pilot each night before bed, and there’s usually enough hot water for a couple showers in the morning.

I even cleaned the screen with my air compressor and an attachment I bent to place the compressed air almost directly on the screen.  I’m positive that screen is as clean or cleaner then the day it came of the assembly line in Mexico, or wherever AO Smith ProMax water heaters are manufactured.

Now it’s getting more and more difficult to get the pilot light lit, which makes me start to wonder, maybe it is the thermocouple.  So I break down and call a plumber to come take a look.  Super nice guy from Fulton Plumbers comes out and I give him the whole sordid history.  He looks, and tells me the thing is still under warranty and I should contact AO Smith and make a warranty claim.

This is where they fun starts.  I submit my warranty claim to .. I think their support email is

The first thing they do is tell me I probably cleaned the screen wrong, and they send me a cleaning kit with a specialty attachment for a vacuum to clean that screen.  They also send a different, wrap around filter to supposedly keep the screen clean for longer.

No you have to consider that they knew this was a serious problem.  At the drop of a hat they immediate knew what the problem was.  They immediately pointed me to a website where they even made a video showing what the problem is and how to clean that screen.  The AO Smith ProMax has such a substantial problem they immediatey shipped out several boxes of junk to try and fix the problem.

I of course play along and use the attachment and the new wrap around filter.  Next day, pilot light is out, no hot water.

I send this email to the support email at AO Smith:

Good Morning,

I have received the cleaning kit and the wrap around filter. I have thoroughly cleaned the flame arrestor screen using the provided attachments and brushes. I have also installed the wrap around filter, however my pilot light will still not stay lit.

Please help! I am getting very frustrated with waking up in the mornings with no hot water.


And SERIOUSLY!  Get a load of the response from AO Smith:

Hello Chris, I do apologize but without having a manifold and supply gas pressure readings or millivolt readings on the Thermocouple it is difficult to determine whether a part is faulty. Pilot outages can happen due to various reasons. You could have an obstruction in the venting causing a downdraft, condensation could cause pilot outages, or there could be a lack of combustion air to satisfy the air requirements for proper combustion.

AO Smith didn’t refer any local plumbers to assist.  They didn’t offer suggestions as to who to call.  They didn’t offer any additional advice.  AO Smith basically spews some techno babble at the customer and says “Sorry” we’re not going to do anything about the warranty.

I think if you like your water heater to actually make and keep the water HOT, you should avoid AO Smith ProMax.  I’ll continue fighting this with them, simply for the principle of the matter, but their customer service is atrocious.  And it would appear that AO Smith will take measures to avoid honoring their warranty.  I think it’s ridiculous that less and 5 years of use and this AO Smith ProMax water heater is basically worthless and the company isn’t honoring their warranty.

52 Responses to “AO Smith ProMax Water Heater = Piece of Junk”

  1. Johnny said:

    My AO Smith ProMax water heater failed after only 4 years.

  2. Johnny said:

    This is without a doubt the worst water heater. I can’t keep it lit now. I have to relight the pilot EVERY DAY! What a piece of junk. And AO Smith won’t honor their warranty. What a joke of a company.

  3. Anonymous said:

    I finally replaced this AO Smith piece of junk!

  4. sherri said:

    I’m so bummed out reading all these blogs that say that AO Smith is terrible, because I’ve had one of their water heater’s since Sept 2006 and just an hour ago the pilot light went out and won’t relight, and I’m sadly being introduced to my future struggles with this device and this company!!!! I am wondering though, since my pilot light will not re-light at all, does that make it the thermocouple?

  5. Sierra said:

    Interestingly enough I’m having the same problem with my pilot light…my water heater is roughly 2 years old….sounds to me like this is a product that should be recalled. I’m going to report this to Consumer Affairs/Better Busines Bureau and see what happens…anyone and everyone who’s having this same issue please feel free to join me. Looks like AO Smith is well aware of this defect and they should handle accordingly.

  6. Chris said:

    Hey Sherri. My experience with AO Smith ProMax was that my problem was NOT caused by the thermocouple. In fact, despite everyone telling me the problem wasn’t my thermocouple, I replaced it anyway, and I experienced the EXACT same behavior.

    I’ll dig it up, but AO Smith is so aware of this problem that they have s special “kit” they’ll send you if you call and complain. I got the kit and it included a new “wrap around screen / filter” thing to wrap around the bottom of the water heater. It also included a brush and and adapter for connecting an angled brush for cleaning that screen at the bottom of the water heater. The screen is called the flame arrestor or something like that.

    I hope you have better luck than I did. I eventually just replaced mine.

  7. GameHater said:

    Going through the same issue with mine for about a month now, I have to wake up early to light the pilot so my Mom has hot water for her shower. Tried replacing thermocouple, can’t find the right replacement part because I cannot locate the model # of my heater…..there is no plate on it which identifies it……tired of lighting the pilot 20 times a day….tried cleaning out the whole gas assembly on the inside but it didn’t help either…. I don’t know what else to do at this point as I cannot afford a new heater

  8. admin said:

    I feel your pain. I can’t tell you how frekin frustrating it was for me to have to make sure I lit the pilot light every night before I went to bed. I would just pray it would stay on long enough to get enough hot water in there so I could take a luke warm shower in the morning. I’ll look to see what I can find, but this was / is such a problem with AO Smith that they will send you special tools for cleaning that stupid flame arrester / screen at the bottom. I mean seriously A.O. Smith ProMax water heater .. if your product is so poorly designed that you have to make a whole screen cleaning kit to deal with this, I would say there’s a design flaw. There’s a video somewhere too of how to clean the ProMax water heater. I think it’s at or something like that.

    If I were you, and I really couldn’t afford a new water heater, I would open a warranty call with AO Smith and start fighting with them. They’ll dispatch someone, but make sure you have the person that arrives at your house make sure they take the proper readings in order to complete a warranty claim. They’ll need something like the voltage reading of the thermocouple and they’ll need the PSI of the gas line.

    Good Luck. I know dealing with AO Smith Pro max and the thermocouple problems is a HUGE issue and a royal pain in the neck.

  9. Pat said:

    I am a new member of the AO Smith water heater from Hell Club! We have been dealing with the hot water nightmare for nearly a month. Like Chris I was told to clean the filter. We ordered a new igniter. The heater is not even 6 yrs. old. The plumber that put the igniter on told me it will not work. He suggested taking piece of s– water heater out to the curb for the trash people to pick up and get another one. Good idea if you have the money which I don’t right now.
    I just fired off a message to the co’s home office. I mentioned I was going to talk to my atty. this wek about a matter we are working on and I intend to ask what can be done about a co. that knows it has sold faulty. Thanks for the web site!
    The new igniter and cleaning the filter did nothing. We are still manually lighting the piece of crap. Pat. R.

  10. Marc Dantonio said:

    Anddddd now I enter the fray as well… My AO Smith Pro Max is 7-8 years old and is now not staying lit. I light the thing over and over and in fact just moments ago watched it go OUT while in the middle of a cycle. The screen is as CLEAN as can be…
    The last time we had a problem with ‘out of warranty’ roofing products in this household, the attorney general was involved and just weeks later we had a new roof.. I am SURE AO Smith will respond to Attorney General complaints IF people all get together in this state (Connecticut) and begin the process… Anyone else in CT?

  11. Mat said:

    This water heater is a piece of junk. I am experiencing the same problem and mine is only five years old. I tried everything and I am tired of relighting the pilot twenty times a day. On top of it my wife keeps nagging about a new water heater day in day out.
    I am overfrustrated.

  12. Adam said:

    I have a Promax unit that is 8 years old. It started giving me fits about 3-4 years ago. Lots of cold showers in the morning. Mine would usually stay lit for some undetermined amount of time and then go out randomly. Sometimes, it gets to the point where it will only stay lit for one cycle. I fixed it with a combination of two things: 1.) Clean the screen well, and on a regular basis. 2.) Dust around the area well. 3.) Clean off the thermocouple. The thing the pilot light keeps warm is a piece of junk part and it gets covered in soot eventually. My theory is that it causes the thermocouple to malfuntion.

    Even this will only get you a couple of months at a time, and make sure you cut your gas off if you try to do anything to it. Most people are probably better off paying someone to do this.

    I’m problematic again after about six months of no issues and the pilot light is going out again. I’m going to be on a mission tomorrow to fix it up using the steps outlined and eventually replace it with a different model. And I can’t believe how much they charge for this brand!

  13. Adam said:

    Three things, whatever. :-)

  14. Mark said:

    I have an A O Smith Pro Max and the same exact problem is plaguing mine. I cleaned the side screens but did not know about the bottom screen. I will try cleaning that but it sounds like that won’t do it. Thanks A O Smith for building a very low quality product and charging an arm and a leg for it. Time to call the New York State Attorney General.

  15. Allan said:

    I had a 40-gallon A.O. Smith water heater that worked fine for almost 21 years. For the past couple years it leaked a little, so 2 days ago I decided to replace it. I bought a Sears Kenmore 50-gallon water heater (made by A.O. Smith) that was except for a larger diameter the same dimensions with the same connection locations. Thus installation yesterday was simple and straight-forward. Immediately last night I experienced issues with the pilot light going out and cold water this morning. I find simply pushing slightly on the thermocouple wire between the gas control valve and the heater housing will shutoff all gas flow (both main burner and pilot). I don’t know yet if I have a faulty thermocouple or faulty thermocouple tip mounting near the pilot flame. Sometimes the pilot lights quickly and other times it takes a lot of igniter striking to light. It is also possible that thermal expansion of burner componenets misaligns the thermocouple and shuts off the gas supply. I’m supposed to have a Sears service person come to my house on Monday and it better be covered under the warranty! I (it appears falsely) assumed that A.O. Smith was still a quality brand of water heater.

  16. Dawn said:

    July 24,2011

    Same problem here! We had our water heater installed in December 2008 it did the same thing with the pilot and some “arrestor” part had to be replaced in September 2010 LESS THAN 2 YEARS!!!! But now July 2011 we’re having the same problem again! just 9 months later and it’s going to cost us another $175. This is so upsetting!!!

  17. Nick said:

    …started this same scenario 3 days ago….YUCK!!! I have vacuumed, brushed, cleaned, re-lit, re-lit, re-lit, re-lit, re-lit, re-lit, re-lit, re-lit, re-lit, re-lit, re-lit, re-lit, re-lit, re-lit, re-lit, re-lit, re-lit, re-lit, re-lit, re-lit, re-lit, re-lit, re-lit, re-lit, re-lit, re-lit, re-lit, re-lit, re-lit, re-lit, re-lit, re-lit,

    This thing sucks. I have to limp through for about 2 months until I can afford to buy a new one…….it won’t be AO Smith or any company whose heaters are made by AO Shith…(wait, I think I misspelled it that second time…or did I?)

  18. Joe said:

    Well after reading all the reply’s I’m starting to feel sick. I must be the lucky winner here..I got my A.O.Smith 6 yrs ago..I beat you all. Same problem won’t stay lit. I’m on disability so money doesn’t come easy..I’ll go clean it now..See if that works..If not I’ll be getting my friends mac 10 and have a field day.

  19. same thing here said:

    Our water heater was installed brand new in 2005, and it has this exact same problem we light it 5 times every day. I cant even google a place to find warrenty info.

  20. Clif said:

    I would sure be intertested in a lawyer starting a class action law suit against AO Smith, I have the same problem with my ao smith piece of junk. It cost plenty to have it put in , hopeing for a quality water heater. Makes me upset to say the least.

  21. Wayne said:


    It appears that I have inadvertently joined an elite club of folks who have been scammed by a company once known for it’s quality products. I’m a GC and residential construction consultant. I find myself in the embarrassing position of having recommended to one of my best clients that they replace a pair of hot waters heaters with AO Smith units having extolled the virtues of quality and longevity which I will now have to retract. I installed my own AO Smith about five years ago thinking I was good to go for fifteen or twenty years. Duh !!! Screwed again. Days later mine punks out and NEVER finishes a heating cycle so there I am, laying on the funky basement floor relighting the pilot just to catch a shave and a shower. Sooooooo disappointed to read these comments!!!! Remember the days when an American company made a quality American product in America for American consumers who thought they were paying for and getting the best. Give me a Bosch on demand water heater any day and let AO Smith figure out what happened to their consumer base. I think its important that folks take the time to add their experiences to these forums. Its a powerful tool that should be used. If someone is starting an action against AO Smith I will gladly join in. Thanks everyone !!!!

  22. Steve said:

    So PO’ed at my AO Smith ProMax GCV50! Had ours installed around Dec 30, 2008 by a local plumber (who obviously is unaware of how poor a product this is), and have had at least 5 plumber visits after having the pilot light go out at least 10-12 times since installed. The various plumbers have basically rebuilt my water heater, replacing every working part, except the tank. Cannot identify a cause and effect for when the pilot light goes out – sometimes the air outside is perfectly calm, sometimes there are higher winds. Our original water heater, installed in 1988, lasted until Dec 2008, and I was just being proactive as there were no major issues (and the pilot light had NEVER gone out!) – I just thought after 20 years, I should replace it with a more efficient heater – now I wish I could go find my old one and put it back.

    I am not sure how we all hold AO Smith accountable – anyone have knowledge about how to start a class action suit?

  23. Dominic said:

    This is a piece of junk. Count me in for class action suit.

  24. Neil said:

    I have two 50 gallon AO Smiths hooked up inline and having the same problem with only one of them??????Count me in for a class action suit also…

  25. Scott Robinson said:

    My AO pro max has been doing this for 2 years. It just started again yesterday, it was 6 months since I had the screen cleaned. I am calling my plumber today and telling him to get this piece of crap out of my home!!!!

  26. Chuck said:

    WOW! This sucks to read all these issues after my 50 gal is petering out. I had thermo couple replaced last year and now acting up again. I’m up in northeast OH and the winters are cold. Not looking forward to going home to tell the wife that we have a piece of crap that is only 3-4 yrs old. What we can do? I’ll do anything to get Promax to make things right, since I can’t afford a new one. Has anyone had any success yet with warranity or Gov help? I wonder how many others that are out there?

  27. Amy said:

    Hi all,

    Single mom homeowner in pro max hell…This is crazy that this many people have the same problem I do. Makes me feel less alone I guess, but even more frustrated! There has to be something we can do?

  28. admin said:

    I am so thankful that I got the ao smith promax heater out of my house. It and the company that supports it are a piece of junk. The water heater failed miserably and their customer support was unhelpful and disinterested in working with me at all to make the situation right.

  29. admin said:

    Just think of how many home owners have a promax (pro max) and just call a plumber or don’t do the research or digging around to find out the real story with this company.

  30. Evan said:

    I feel like the newest member of A.O. Smith Anonymous…Hello, my name is Evan. And I bought an A.O. Smith water heater 5 years ago.
    The pilot light on my Promax began going out 5 days ago. I would relight and relight. Finally had our gas utility come out and take a look. He took a brush to something near the burner and it stayed lit for 24 hours. Now I’ve given up on relighting and we’re “showering” with a pot of hot water and a cup! Ridiculous!
    I just bought a replacement thermocouple but decided to Google before installing. That’s when I came across this blog and all your helpful responses.
    Not sure what to do next. Considering a tank-less unit and kick A.O. Smith to the curb.

  31. kat said:

    so I have been in a.o.Smith hell since 2009. The condo we purchased came with this junk installed brand new in 2005. Every day I have to switch the thing off and on at least 15 times a day. Its been serviced 3 times and it still will not stay lit. I seriously want to blow the stupid thing up – mythbusters style! It has to be the only thing its good for, because heating water is not it! Under no circumstance should anyone install this brand water heater, its nothing but trouble and money. I will be replacing it ASAP!

  32. jon said:

    I have had three pro max water heaters in the last ten years. The first two leaked and the third one had a pilot light problem before it started to leak. Calling the Promax water heater junk gives a bad name to junk. A. O. Smith should be ashamed to to even continue to sell this water heater. Having my Promax replaced today with a different brand. May the C E O of A. O. Smith take a cold shower in the morning.

  33. Brian & Alexis Lannan said:

    Our unit was replace with an AOSmith the 2nd year in our home by the warrently company (’06 or ’07). We started experiencing this problem approximately 1-1/2 yrs ago.

    Called the Gas Co to check it out and they told me if the air flow was restricted it clogged “things” up; to make sure and clean around it frequently. Problem has persisted and gotten worse in the last 6 months. Decided to check on the internet and happened upon your site and comments. I’m floored by what I’ve read! Based on the comments, I’n not even going to try and contact them. Count us in on an Class Action Law Suit.

    B & A Lannan

  34. Kenny said:

    Any other good water heater to replace AO? My 2005 AO has stopped lit the pilot since last week. I had the coupler replaced (my plumber told me that was bad) two days ago. Now the pilot went out again.

  35. Lee said:

    Same stuff here. 4 year old Pro Max. Pilot won’t stay lit. Don’t like the concept of dealing with the new sealed combustion chambers so will have a plumber take a look.

    Had a pro max in the last house….T&P valve started leaking after 3 years….replaced. This one had the same issue after 2 years and I replaced it. Now the pilot light issues.

    I take care of my stuff, drain the water heater once a year, and so on. Obviously, based on this and many other internet posts on the product, no one should have this product in their home. Last two homes I bought were new. If I ever move again and get into a new house and see their product in the basement, it will be replaced before I buy it.

    The product sucks. The company seems to know it….and doesn’t care. Why is America going down the toilet. Because of things like this. Typed by a proud American veteran of two wars.


  36. admin said:

    A genuine thanks for your service to our country.

  37. Frank said:

    Does anyone know if a Class action against A.O. Smith is in progress

  38. admin said:

    I have obviously seen a lot of discussion about an action against AO Smith, but I haven’t heard of any specific action. Honestly I’m a little surprised that an attorney hasn’t seen this and contacted someone about starting an action.

  39. Coveybeth said:

    2 cold morning showers in to hating my 3 year old AO Smith. I googled it this morning to see what I needed to do to fix my problem…..and apparently I just need to get used to it. Unhappy.

  40. David said:

    These are piece of crap. I have even had a new roof vents cut into my soffits and a new vent hole runt hrough my roof and it still shuts off. I have contacted the BBB and they have numerous complaints. I am pulling mine out and shipping it back to them with my shoe marks on it like the copier from Office Space. I have also sued my plumber for putting these in with them knowing darn well they will get repeat business because these things are crap.

  41. David said:

    These are a piece of crap. I have even had a new roof vents cut into my soffits and a new vent hole run through my roof and it still shuts off. I have contacted the BBB and they have numerous complaints. I am pulling mine out and shipping it back to them with my shoe marks on it like the copier from Office Space. I have also sued my plumber for putting these in with them knowing darn well they will get repeat business because these things are crap.

  42. Elite member of the A.O. Clan said:

    I feel proud to be in the Mickey mouse club of ao shit tanks. I am a 38 year old former Marine/ buisness owner father of three and sometimes wonderful husband. I want to cry. I am so frustrated that I want to ball my f-ing head off and so mad I want to go on a A.O. Killing spree. I CLEANED THE FKING SCREEN,I BLEW OUT THE COMPARTMENT WITH MY COMPRESSOR,I REPLACED THE WHOLE FKING BURNER ASSEMBLY AND FOR 13 MONTHS MY FAMILY HAS SUFFERED FUCK YOU AO PEICE OF SHIT. I AM GOING TO BLAST THAT PEICE OF SHIT AWAY MIGHT EVEN TURN IT INTO A MISSILE AND LAUNCH IT UP AOS’ ASS. Tankless here I come and as for ao I am going to launch a personal campaign to bad mouth all of their products on every forum news paper and any other media I can get to listen. I am a general contractor and any product those fucks make will never see the light of day on my sites. I pride myself on bringing broken things back to life and thus far have been so stubborn and not gotten a new one but you can’t make a silk purse out of a sows ear. P.S Im sorry honey for putting you through hell for the last year.

  43. Tamika said:

    So, been without hot water for two weeks and I’m seriously tired of boiling water for baths and cold showers. I’ve had 3 people look at this piece of junk and all said the thermocouple was bad. The local appliance store doesn’t carry the part and stated I’d have to order directly from the company. So I’m lasting here thinking that I should order the part and I find this sure. OMG…. Guess I’ll be getting a new water heater! No need to pro omg the hell! I can guarantee you this…..sure as hell won’t be a ao smith!

  44. Joe in NJ said:

    I am no different than anyone else above. Same issues. Same attempts to resolve. Only slight difference in my story is that they outright told my latest plumber who tried to resolve the problem that my unit was outsie the warranty period.

    I accepted that answer which was in Oct. 2011. Seemed legitimate. I wasn’t sure of the exact install date. But this morning, on yet another occurence of my pilot light not working, (always on a Holiday or weekend!!!) I noticed that there is no way that my water heater is out of warranty.

    Count me in for class action. Calling first thing tomorrow morning. Have a few colleagues that may want to take it on. If i get anyone on it, will have them post here.

  45. Ryan said:

    Same issue with me. Is there any lawyer attempting a class action? Its obvious the company know of the problem and are just ignoring it.

  46. Jon said:

    Another sad victim of the A.O. Smith nightmare. I ended up replacing the entire pilot assembly and it still won’t stay lit!

  47. sam said:

    Ditto to the problems with AO Smith ProMax. Cleaned the air intake screen and it stayed lit for a couple of months. Just went out again and doesn’t even stay on for a full cycle. I’d be interested in a class action suit.

  48. Aaron said:

    I got the same pilot won’t stay lit issue for GVR-50, which is installed in 2006. I will try to replace the piezo ignitor first, due to the 3 days of intensive relight activity.

  49. Petey G said:

    My peice of shit AO smith water holder, not even a heater cause the fucking thing keeps going out sucks ass. This thing is 4 weeks old! It replaced another Ao smith that sprung a leak 3 years in. The company would not honer any warranty. never ever again will I buy anything that starts with the Letters AO!!!!! They got me goooooooood!!

  50. Tom said:

    Six years and my nightmare begins. Had problems with it oing out every six months or so but now won’t stay lit at all.

  51. Desiree said:

    I have had this 50 gallon hot water heater for 3 years and it has always gave me problems with the lighting. now it wont stay light at all. does anyone know the phone number to this company?

  52. Desiree said:

    I purchased this 50 gallon water heater 3 years ago, i have always had problems with it staying lite. now it wont light at all. Does anyone know the phone number to this company

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