PLEASE HELP! I have been having problems with my water heater for several weeks now. At first I noticed we had no hot water one morning. I unplugged it-plugged it back in and it came on and worked fine for a day or so. It has worked off and on by me doing this. Well...now it comes on, but wont stay on long.It comes on as normal (The blower motor comes on, I hear a click then the burner lights),but then the burner goes out. It goes through the starting cycle 4 times before finally shutting off. The green light on the temperture control box flashes 6 times. Thanks
Sounds like a rectification problem.. Try cleaning the flame rod. I am not familar with this unit. Does it have a pilot or hot surface igniter?? If pilot make sure clean and striking flame rod
hoffacard,
I'm having this same problem with my A.O. Smith FPSH-50 hot water heater, did you ever find the fix and can you share the details with me?
Here are the details of my problem:
I have a ~6 year old A.O. Smith FPSH-50 gas water heater. This is a power vent unit with electronic ignition. The burner was running fine (as needed) until today...
...the TPR valve was leaking intermittently and the water pressure gauge I attached indicated no sign of high pressure (above 80 psi). I replaced the TPR valve and when I turned the gas and water supply back on and then set the thermostat to hot and turned the power on, the burner ignites, but will not stay lit.
When the power is turned on, the power vent blower starts and runs for a bit. The hot surface igniter heats up and glows orange. Then there is a click and gas flows, is ignited, and burns for a half second and then another click seems to cut off the gas supply and the burner goes out. The water heater cycles through this 4 times before giving up. The green light on the thermostat is blinks 6 times and then blinks 4 times. Any ideas what I could have screwed up during the TPR valve replacement? The thermostat did get a little wet because I didn't drain the tank enough before removing the valve and a few cups of water drained down the side, but the thermostat control was definitely NOT submerged.
thanks in advance,
Brian
p.s. as this is a do-it-yourself project, against my wife's better judgement, i hope to get this resolved before she gets home or at least before she needs a shower tomorrow morning.
It sounds to me like you have either a problem with the air pressure switc or the tubing that leads to the induction blower. Moisture develops inside the tubing or the nozzle that sticks out of the induction fan or the air pressure switch. The light blinking are error message usually there is a trouble shooting guide either posted right on the unit or in the user manual and this will guide you in the right direction. If neither are found, you can go to the Ao Smith website or call the manufacture directly. I hope I have given some direction in your problem.
somehvacguy,
Thanks for the reply. I did find a service manual on the A.O. Smith website. I went through some troubleshooting steps and everything checks out. According to the SmartValve sequence of operation, once the main burner ignites, the flame must be sensed within 4-5 seconds or the gas valve is de-energized and the cycle is tried again three more times before giving up. Also, the SmartValve will try to reset itself every hour once it's in this lockout state (that's what the 6x blinking led indicated). This afternoon I was turning it on to observe the operation sequence and then when it failed, I'd turn it off to troubleshoot. Around dinner time I left it alone, but turned on for a while and before bed I went down to check on it and the blower was running and the burner was heating away. I'll see if we have hot water tomorrow morning, but for now it seems the mystery has solved itself, though I don't understand why.
Thanks again for the advice, it kept me from giving up, though in the end that's what seemed to do the trick.
Brian
hoffacard,
Eventually it will fail and I can say with 95% certainty it's a dirty flame sensor. Unplug the water heater, remove the door at the bottom and then take out all of the screws around that observation window and the gas inlet pipe, on mine it was 7 screws. Now pull out the burner, attached is the igniter and flame sensor. On this pic, the flame sensor is the metal rod on the right:
Get a piece of 60 grit sand paper and sand until it's nice and shiny, especially the tip. Reverse the process and plug it back in. Wait 1 hour and enjoy a nice hot shower!
It's a piece of maintenence that most water heaters and furnaces need occasionally, like brake pads on a car, nobody expects them to last forever.
BTW, it might be a nice service reminder that if you need to clean it every 5 years, to also replace the annode rod at the same time and drain the tank to clear out any sediment, it will increase the life of your water heater significantly!
I would like to thank you for the tip. I sanded the tip of the flame sensor rod and put it back in and it fired up without any problems. Your post saved me a ton of time because I was constantly fighting the stupid thing.
I failed to mention that you need to shut off the gas, and also that you need a large open end wrench, I think 3/4, in order to remove the burner, but I assume you figured that out.
I have the same hot water heater.
My symptom was a lockout condition with the Green light and A B amber lights remaining on after the heater gave up trying to light. Per the manual this indicates low gas pressure, which I didn't believe. I guess the flame sensor was dirty enough that it didn't sense the burner was actually lighting and shut down assuming low gas pressure. (The burner was lighting every time before it shut itself down.)
I saw this post and figured I would clean my flame sensor as well. IT WORKED!! It appears a dirty flame sensor can manifest itself in a number of different error codes.
Back to the top for this marvelous tip!! Thanks a bunch.
My neighbor lives alone and is disabled. Her water heater hasn't worked in a couple of days. She called this morning to see if my hubby could help her so she wouldn't have to pay a repair person. My hubby was at work so I found this post. I followed Mundlin's directions and found out that the rod was rust free but the burner itself had half an inch of rust on it. We cleaned it off and now it works fine. Thank you for the info, you saved her $100 and it was so easy for us women to do!
Well..good job ladies!! See..we men are going to become superfluous eventually. Pretty soon every DIY question will have been asked and answered and you can just get rid of us...lol.
Again...glad you fixed it!
Mrs Shak -
The flame sensor does not get rusty. It sits above the burner and igniter in the flame any time the water hearer is heating and therefore get a greyish black film of soot. That still may be the problem and taking it out and putting it back in might have jiggled it enough to limp along for a while. If you go through the trouble of taking it out, clean it, it is time well spent.
I have the FPSH 40 gallon model. I have the same problem with the flame sensor and discovered the solution a couple of years ago. Having a bit of an electronics background gave me some idea of what I was looking for.
The issue that I have is that I have to do this process every three to four months. The first time I had to do it was after the heater was only two years old.
I now have new problem of having to keep turning my water temperature up to keep from running out of hot water. There is just me and my wife. Now with the heater turned up all of the way we hardly make it thru our morning showers. The water is initially very hot (too hot if used straight) but after only a few minutes we are reducing the cold water until we are running straight hot water which is hardly warm.
Would this indicate that the temperature sensing is going bad? If so does the tank need to be drained in order to replace it?
Thanks
I also have the same model in this thread.
FPSH 50
Series 234
Serial # ML98-0025622-234
Model J00N010000
The Inducer Fan Squirrel Cage plastic impeller blade is warped, and rubs the housing. The reason it warped is due to overheating, caused by the PVC 90 a couple of feet above the unit cracked in half. That is fixed now. I took out the 90 and replace it with a 'sweep' 90, I think the regular 90 PVC was causing it to heat up too much.
The unit runs, but sometimes when it calls for the blower to kick on, the motor has a hard time getting it to spin. This I know is because when it rubs, it gets a little stuck, and if it's at this point, the motor hums. I can actually twist on the impeller housing a bit to get it going.
Searching for replacement - only comes up with this part, which is the WHOLE exhaust unit, which includes the control box, motor and fan/housing - 9004434105 (182775 old part #)
which runs anywhere from $350 - $550. It is made by FASCO for AO Smith.
Does anyone know if you can order and replace ONLY the squirrel cage fan inside the housing?
There is another FASCO unit - 7021-10195 - LINK
That is a 'six prong' that looks like it has the same impeller housing, does anyone know if this is the same impeller / different electronics?
Thanks
there has to be away to buy just what you need
How do I getthe burner, and igniter and flame sensor out? I got the door off, but laying on the ground I cannot see into the unit to find the burner.
Green69Charger -
Your problem is likely sediment in the bottom of the tank. Calcuim and other disolved minerals precipitate out of the water when heated and collect at the bottom of the tank. You may also have some sand and other imputities in the water in the tank. This acts as an insulator so the water will not heat as well, and it also wastes gas.
1. Un-Plug the water heater.
2. Plug a garden hose into the drain tap at the bottom of the tank and run to a floor drain.
3. Turn off the water to your house or water heater.
4. Open a hot water faucet up stairs.
5. Open the drain tap on the water heater and completely drain the tank. You might observe sediment coming out of the hose. Once the tank is completely drained:
6. Close the hot water tap upstairs opened in step 4.
7. Turn on the water to you house that was shut off in step 3.
8. Observe the water coming out of the garden hose. Once no more sediment comes out and the water is clear, close the drain tap opened in step 5.
9. Re-open the hot water faucet upstairs opened in step 4. Air will come out, it might startle you as it can be loud. Once the air has stopped coming out and pure water comes out, close the faucet.
10. Plug the water heater back in that was unplugged in step 1.
If you had significant sediment, you will be amazed at the results.
qpnsrme -
You need to remove the large (1 - 1 1/4) compression nut that holds the burner's gas line at the bottom of the thermostat / computer on the outside front bottom of the water heater. The whole assembly looks like this:
Remove the nut that is in the upper right corner of the pic
I have a 7 year old AO smith 50 gallon experiencing the problems listed in this thread. The flame will not stay on long enough to heat the water and eventually goes into a fault mode. The first light from the left below the vacation arrow is green and the A and B lights are amber.
Here is what I tried so far. I cleaned the flame sensor light indicated in this message thread and it bought me another three weeks before it happened again. Next, I replaced the ignitor and flame sensor. The same problem exists. I called the company who surprisingly was willing to help even though my warranty expired. He had me check the electrical outlet to ensure I had no current coming over the neutral wire which would indicate a polarity issue and/or ground issue. The outlet passed this test but I switched outlets anyhow.
The unit ran for another three weeks until this week. now the problem is back. I am wondering if there are some other tests or issues that someone maybe aware of before I call a licensed plumber.
Thanks in advance for the help.
It's my understanding that the flame sensor uses a process of flame rectification which sends a current from the flame sensor through the fire TO GROUND. I would appreciate if someone would address this.... does the BURNER act as ground?? Should the burner be cleaned of any debris, rust, etc????
We've had ours for 8 years and the last 6 have been nothing but an headache with this heater. Talked with customer support and they said that you have to clean the dust and debris when you find that you have no hot water. I will never purchase another A.O. Smith...which leads me to...I'm now replacing it and need to know what the best natural gas water heater is out there???
wow - worked like a charm. I am only mildly handy, and getting out the burner was a snap. I cleaned it with sandpaper, put it all back together, and BINGO! Works like a charm. The whole thing took me about 20 min.
Thanks for the great advice!
I've been having the same issue with my 40 gal AO Smith heater. Over the past several months I've had to clean the burner and flame sensing rod several times. Now that's no longer effective. I've noticed the flames are larger than I've observed before and are orange/yellow as well. I learned this may indicate too much oxygen (or not enough gas) in the flame. I also observed that when I have the gas valve fully open, the water heater will go through its cycle and result in a lockout (i.e. 6 blinking lights). However, when I close the gas valve to decrease the flow to the burner, it results in a smaller flame (still orange though) and stays lit until the water is heated. So I think this is a work-around that may buy me a few more days/weeks.
I'm thinking of replacing the complete HSI burner assembly - any others have a suggestion of whether or not that would be successful? Do the large/orange flames indicate I should consider another cause for the problem (maybe the blower unit?)??
Thanks for any input!
Note: the unit is in a dry basement (house built in '03) , raised from the floor by resting on a few bricks, and has clean air to breathe.
Hi,
1. There is no way to adjust the flame to the burner. It is either on or off.
2. 6 binking lights sounds like a smart valve. This is one green light on the side correct?
3. Most likely out of warranty. The igniter assembly comes as a unit with the flame sensor. Call ao smith and give themn your s/n. The part is about $50.
4. It may be a blower assembly issue. The CFM of the fan gets weaker as time goes on, and may not pull in the pressure switch. This will cause a lock out but a different code possibly.
5. The flame sensor may also produce that code.
6. As far as the flame being yellow, it should not be. I would believe the door to the burner is not sealed and you have two doors then the burner is open, correct?
7. The smart valves are discontinued and were plagued by issues. Now its all intellivent valves. So your plame issue mnay be gas valve related.
My best advice to you is to replace the unit. Try not to through too much money at that heater. Its already 8-9 yrs old I would imaging. The first 4 didgits in the s/n tell the yr it was made. You said the house is 2003 so it should be close to that.
Mike NJ
Great, thorough response Mike - I really appreciate the feedback! Re: your points below...
1.) That's what I expected to, but giving it about a 1/4 turn definitely decreased the flame sizes. This is the valve which is 'closest' to the thermostat unit, which I think is a ball valve.
2.) Yes, one green light on the side and yes, it has a smart valve. The troubleshooting guide has a laundry list of potential causes for the 6-light lockout code.
3.) Yes, def out of warranty. Got in touch w/Winnelson on west side of Indianapolis - going to get the part tmr morn, but not sure it's going to be the right solution.
4.) So if the fan is weak, that would prevent the burner from staying lit? It's been consistent with the 6-light lockout code so far.
5.) That's good to know - if the part replacement works, that will prob confirm the sensor was bad....right?
6.) Yes, had the two doors off to observe the flame and lighting sequence. But I did replace the doors and was still able to see the reflection of yellow flame off the bottom pan.
7.) I'm assuming it wouldn't make sense/be feasible/be reasonable to retrofit it with an Intellivent valve if that's the prob.
OK - so if the HSI burner replacement doesn't resolve the issue, then most likely it's most likely a blower or smart valve issue - and would be better to replace the w/h.
Thanks again!
OK.
1. Dont touch the valve that turns the gas on and off. It should be fully opened.
4. If the fan is weak it will not pull the pressure switch in. This is on the side of the fan assembly and has a hose going to it. I believe its square kind of. Also a blocked flue outside. (Shrubs, kids stuffed somthing in the vent,...etc) Also what makes the fans weak is the length of vent. Some plumbers vented too long and or used too many elbows. There is a limit. It should be in your manual. The unit will work when new because the fan CFM is initially set at a higher performanc. They degrade overtime and the CFM becomes less. You could be at a midpoint if you know what I mean.
5. Flame sensor and igniter come as a unit. The ignighter looks like it has a machine gun barrel around it with holes. You can try cleaning the flame sensor(the metal rod next to the igniter) with emery. It may not be detecting the flame. You will know because it will lite for 3 seconds then go out. If it dont light at all it may be the pressure switch.
6. If you dont have the doors on sometimes it will not like. With the doors off the air is drawn in the opening and blows the flame away from the flame sensor. The doors need to be on. At least the inner door if you want to observe.
7. You cant retro fit.
Since I was a ao smith rep I could say if you had a plumber come to change the gas valve, igniter, and fan assembly it would run about $600 bucks. I believe a new heater in that model you can buy for about $900.
If you change the part and it dont work I would not throw money at it. Replace it.
Mike NJ
So I picked up the replacement HSI igniter/sensor this morning and replaced the one on my burner assembly - as you can see (if there are no probs with the picture link), the new sensor has a much different shape/angle and doesn't come close to being 1/8 from the burner - am I missing something or is this simply the wrong part?
Thanks!
Ahh memorys...
Yes that is the new bent part. They dont make the original. There is a straight one also. That one bends away from the burner as I recall. I think I prefered the straight on because it went out as far as the ignighter and I would bend them myself.
But I had many on my truck so if I damaged it it did not matter. You paid for that so I dont recommend it. And yes this was an issue I had with AO smith.
Dont break the ceramic if you attempt to bend. The dumb thing its not even vertical. Its off at a 45 angle and it makes it that much harder to bend up and towards the burner.
Hey now you know why I tell customers they are better off replacing these waterheaters. Its a 03 but older technology with the gas valve and all.
I would put in in without any mod and see how it lights.
Let us know.
Mike NJ
Hi Guys -
OK, so I cleaned the sensor / flame rod, cleaned all the debris etc......put it all back together and now I'm getting the lock out code I believe (6 lights come on then just shut off). It doesn't fire up at all now. Did I do something wrong that would cause this?
For the past few month it's been acting up, sometimes it would fire up and stay lit and other times it wouldn't - like it had a mind of it's own. I was first getting a code with 1st, 4th, 5th lights coming on. I was told this was an Air code 6 and that cleaning the rod may do it. Did a search on google and found this site and completed the step by step instructions to clean it.
It's an 8-yr old AO Smith - FPSH 40 270E
Any help would be appreciated.
Thanks
Jordan NJ
Just a note on these units also. The wire harness from the blower to the gas valve travels inside the water heater. These often fail and cause intermittent faults and failures. You may be able to wiggle the harness at the top and bottom where it enters the heater.
A continuity test often will diagnose it but sometime not.
The fix is to disconnect the harness at both ends, cut harness off at both ends where it enters the heater, then install a new harness outside the heater. There is no way to route the harness internally the way it was. The new harness just hangs there.
If you have your manual it tells you the codes and cause. If your more specific I can look it up. Such as Vacation, A and B light is lockout after three ignition attempts.
Mike NJ
Hey Mike -
Actually, I don't think it's flashing a code. I turned the switch on and all the lights flash up (I think as normal) and then one sec maybe 2 sec later it just shuts off....it doesn't even have a chance to light. And no codes are being flashed. At least before there was a code and the pilot would try to light but now after I did the cleaning this is happening.
Jordan NJ
Well there is a series of events that takes place. It could be as simple as its already up to temp. When you turn on the poer to the unit all the lights will light for a moment then go off.
Have you tried turning the temp up all the way? If you get no lights on when you try to turn the temp up then I would say you are losing poer to the gas valve. This power comes from the wire harness. They often fail.
Like I said try wiggling the harness at the gas valve and blower. Also where they enter the waterheater groumets.
Unplug both molex connectors and reconnect.
let us know.
Mike NJ
Mike -
Thanks, I will try this tonight. I did not try turning the temp all the way up but I'm assuming that this is not the issue since it still has not kicked on...it's been 3 days. Where exactly is the wire harness? At the top of the water heater? I did see some plugs so I'll just assume that it's the molex connectors.
Jordan
Mike -
It worked....thanks for the advice....I took a nice hot shower this morning...AHHHHHHH
Jordan
Great job!!!!
What exactly did you do??? This info may help others.
Mike NJ
Hi I have an ao smith promax 50 gallon water heater gpvh built 2007. It has been going in vacation mode for a few months and we end up not having hot water shortly after it has been used. Now It's going into vacation mode more often. Any help would be appreciated. Thanks, Liz
Hi,
Do you mean VAC, A, and B lights come on? That is a lock out code from failure to ignite.
2007 is all under warrany except labor. If your handy you can call AO Smith and get the parts free.
The most common failure is the HSI ( Hot surface igniter ) that comes as an assembly with the flame sensor.
It could be the pressure switch at the flue fan assembly.
Check your warranty here. Click on the heater info tab when the page opens and input your info.
https://warranty.hotwater.com/default.aspx
Mike NJ
Thank you for replying Mike.
Yes, VAC, A, and B lights do come on. How would we be able to tell what is needed from the options you listed?
Need to replace pressure switch and mfg. says they only replace entire blower unit. Anyone know of source to order the switch alone?
What you dont want to pay $450 bucks for the fan assembly?????.........LOL
Fan switch. $82 bucks.
A.O. Smith 9004658105: Pressure Switch
Call and verify part #. AO Smith change all thier part #'s. This should be yours but call this company and verify.
Mike NJ
Tags: year, smith, water, heater, heat, water heater, flame sensor, flame sensor, pressure switch, that have, water heater, bottom tank, drain tank, green light
