State GSX40YBRS Stays lit for about 2 minutes.

[pjw73nh]

Hello,

 

State HW heater 40 gal nat gas. Mod GSX40YBRS Ser# H04A007252. Installed 10/2004.

Has been fine since we bought the house in 5/2013.

All of a sudden, today, my son (he's 60 miles away) woke up to no hot water. Gas stove and gas hot air furnace are fine. (Not a supply issue).

No pilot on HWH.  It will restart and appears to go out on safety.

I can restart the pilot fine. But when I let go of the pilot override and go to turn the tstat to the desired temp, the main burner fires up, and will run for approx 115 seconds, then I hear the "bink" of the gas solenoid closing and the burner shuts off immediately.  It does not fade slowly (as if it was a supply issue), it goes from strong flame to off immediately at approximately the 115 second time mark and the "bink". 

I had him clean the intake screen at the bottom and it made no difference. 

When I looked at the main burner flame through a little square glass window (via facetime), it was mostly blue with a little yellow at the tips.  It also looked a little wavy or wobbly.  I don't have any comparison for it, so I don't know if this is a good flame or not.  Also, the camera was not good enough where I could see if the thermocouple is being engulfed by the flame or not. 

I am going to drive out there tomorrow and have a look-see.  I am probably going to take the burner assy out and clean it. Or at least access it to clean it.  Do I need to take it out to clean it ?  There is also talk of a "ceramic disc" as well, but I can not find it listed on the diagram or parts list.  I have not been inside a (residential) gas HWH before so I don't have a lot of familiarity with them.

I have a diagram and parts list.  Are there any tips, tricks or suggestions that would be worthwhile for getting to the innards of the heater ?

I did notice that there are 4 "items" that connect to the control.

1. Main burner (large) tube (gas supply)

2. Orange wire for igniter.

3. Small copper capillary (I presume for thermocouple)

4. Small silver/steel tube about the same size the capillary above.  Pilot supply? 

Are there any other tests or diagnostics can I have him do before I arrive there?  Where tomorrow is Saturday, should I take any replacement parts with me (assuming I can get them today) ?   Thermocouple perhaps.

Thanks for any suggestions you may be able to provide.

-Paul.../NH 

[pjw73nh]

My apologies in advance for the spacing. I'm not sure why it did that.

[Budget Appliance Repair]

Most likely and common problem on this style of water heater is a lint/dust plugged ceramic(carbonite?)disk.  There should be a black plastic grill/cover over the air intake area, (called a LDO -Lint/Dust/Oil Screen), to keep lint and dust from being sucked up into the ceramic disk.

 

They have phased out this style because of so many problem with them, not a install and forget/replace thermocouple in 10 years deal like old day water heaters.  No one every maintains them as instructed in the installation manual, (probably because no one every reads it).  The air intake area under the water heater/bottom of ceramic disk should be cleaned every 6 months.

 

Without a special cleaning tool it's almost impossible to get anything in there to clean it well.

This is what you need and the web page also has some good pictures and videos of what you need to do to clean it.

http://tightspotvacuum.com/

 

Some times depending on how long it has been since it has been cleaned, just using this brush from the bottom with a good strong vacuum isn't enough to clean it sufficiently.  On a few that I've done I've had to pull the burner and pour water through from the top while vacuuming from the bottom to get all the impacted lint and dust out of the ceramic disk.

[Patricio]

I have this brush & when hooked to a shop vac it does the job on them disks.  I think it was BAR that turned me on to it.

[pjw73nh]

Thanks for the tips folks.  I went out there today and had a look-see.

 

LDO screen was dirty, I cleaned it.  Made no difference in performance.   I have to ask why the other holes in the bottom case are not screened as well? There are 4 holes and only two are covered.  Don't they all go to the same place?

 

I downloaded the service manual and checked thermocouple output.  Manual says it should be 20-30 mv DC at the 45 second mark.  I got 24.7 mv.  Seems like it should be ok.  I took the burner/pilot assy out and cleaned it with low pressure compressed air. There was schmutz (rust flakes etc) on the top center of theburner, but none of the channels were plugged.  I scraped a little debris off the end of the pilot tube, and wiped off the thermocouple.   Vacuumed out the burner chamber.  I could see what looked like a large white "honeycomb" plastic circle under the burner floor.  Is this the infamous "ceramic disc" that needs to be cleaned?   I was able to reach SOME of it from the top and some from the bottom. Gonna order one of those fancy brushes.   In any case, I reassembled, and tested it.  It fired up fine, flame was mostly blue with orange tips. It stayed on until the water was up to temp.  

 

Previously it was shutting off after about 115 seconds.  This time it went until tstat was satisfied, and main burner shut off.  Pilot was still lit.  I left to do a few other things around the house.  I came back about 30 minutes later.  Pilot was out.  I re-lit it and turned the temp control up to start the burner.   It fired up fine and stayed until I turned the control down, when it went off the pilot was still lit. It has been fine since.  Probably 10 hours.  But there hasn't been a large draw on the hot water either.  It did cycle once when we used the shower and the pilot stayed lit.  

 

I noticed at one point when the burner had been on for a while, the flame was very orange/yellow, but then went back to blue after a few minutes.   I also noticed that when the main burner is on, it looks like it "drags" the pilot flame a  little bit. 

 

So I guess I am not sure if it's fixed or not.  I tried to read the thermocouple voltage AFTER I cleaned it, but it went out on safety, and I didn't know how to reset it.  Just wait?   Anyway, I left it as is and I'll have to monitor it. 

 

So far so good.  

 

Any more thoughts welcome. Thanks again for all the help. 

[Patricio]

Sounds like it was starving for oxygen. 

[Budget Appliance Repair]

What did you use to clean the ceramic disk?

 

If not the vacuum brush shown then you most likely got some of the blockage out but not all.

 

The only way to do this right is with the above referenced tightspot  vacuum brush and sometimes the addition of pouring water from the top while vacuuming from the bottom.

[pjw73nh]

I used a tooth brush duct taped to the end of small crevice tool attachment to a vacuum cleaner.  I am sure I didn't get it all.  But the top of it (under the burner assy) was all white (clean) to begin with.  It looked like it was new, though I can't tell you what new should look like.  The hole in the top of the "pan" (the bottom of the burner chamber) was about 4 inches around, so I could not get to all the edges on the TOP of the disc.  And I couldn't get my head/eyes low enough to see how the bottom looked through the vent holes.  Pilot still lit this morning.  22 hour later. 

 

As I mentioned above, I am going to order one of those brushes. 

 

My questions still remain.

 

1. Why do they only have two of the 4 vent holes covered with an LDO screen. Seems pointless to me if they all go to the same place. 

2. How do I or how does the safety reset when the pilot goes out.  Time?  How long?  Do I have to do anything with the pilot control or temp control? Or just wait ?

 

4.  And lastly,  If these "newer" HWHs all have this type of ceramic disc filter/setup, why do the manufacturers not make it a bit more accessible?  Maybe like a "slide out" drawer/frame like a furnace return air filter?  It seems they go through a lot of effort to make the burner/pilot ignitor assy easily serviceable and it seems they need LESS maintenance than the disc., Why not this filter if it needs periodic maintenance ?  Just thinking out loud. 

 

Thanks for the quick and informative replies/

 

Paul.../NH
"

[Patricio]

I used a tooth brush duct taped to the end of small crevice tool attachment to a vacuum cleaner.  I am sure I didn't get it all.  But the top of it (under the burner assy) was all white (clean) to begin with.  It looked like it was new, though I can't tell you what new should look like.  The hole in the top of the "pan" (the bottom of the burner chamber) was about 4 inches around, so I could not get to all the edges on the TOP of the disc.  And I couldn't get my head/eyes low enough to see how the bottom looked through the vent holes.  Pilot still lit this morning.  22 hour later. 

 

As I mentioned above, I am going to order one of those brushes. 

 

My questions still remain.

 

1. Why do they only have two of the 4 vent holes covered with an LDO screen. Seems pointless to me if they all go to the same place. 

2. How do I or how does the safety reset when the pilot goes out.  Time?  How long?  Do I have to do anything with the pilot control or temp control? Or just wait ?

 

4.  And lastly,  If these "newer" HWHs all have this type of ceramic disc filter/setup, why do the manufacturers not make it a bit more accessible?  Maybe like a "slide out" drawer/frame like a furnace return air filter?  It seems they go through a lot of effort to make the burner/pilot ignitor assy easily serviceable and it seems they need LESS maintenance than the disc., Why not this filter if it needs periodic maintenance ?  Just thinking out loud. 

 

Thanks for the quick and informative replies/

 

Paul.../NH

"

Before I got the brush I used a tooth brush...pain in the neck

1. I can not explain manufacturer's mode of thinking
2. Pilot heats thermal coupler/thermal pile which generates mVolts.  Voltage tells valve flame is present
3. ?
4. See #1,    You might send them a letter explain your concerns.   Personally I think the vacuum brush ought to come with each W/H.  The owners manual does recommend cleaning periodically.

[Budget Appliance Repair]

My questions still remain.

 

1. Why do they only have two of the 4 vent holes covered with an LDO screen. Seems pointless to me if they all go to the same place. 

2. How do I or how does the safety reset when the pilot goes out.  Time?  How long?  Do I have to do anything with the pilot control or temp control? Or just wait ?

 

4.  And lastly,  If these "newer" HWHs all have this type of ceramic disc filter/setup, why do the manufacturers not make it a bit more accessible?  Maybe like a "slide out" drawer/frame like a furnace return air filter?  It seems they go through a lot of effort to make the burner/pilot ignitor assy easily serviceable and it seems they need LESS maintenance than the disc., Why not this filter if it needs periodic maintenance ?  Just thinking out loud. 

 

Thanks for the quick and informative replies/

 

Paul.../NH

"

 

1. All the one's I've seen had only the two long slots just under the burner chamber opening, if yours has four and the LDO screen looks like this:

Then maybe it should have had two of these screens.  They do have a replacement screen that comes with the new pilot/thermocouple/ignitor assembly that wraps all the way around the bottom so any and all air intakes at the bottom are filtered.  It looks like this:

2. If the pilot goes out because of a plugged up air intake or an explosive vapor event then the thermal cut-out that is in the thermocouple line opens letting the pilot safety magnet in the gas valve drop out and shutting down complete gas to pilot and burner.  It is an auto resetting cut-out, opens around 175-195 degrees Celsius, (yours is a 190), depending on the rating of the thermal cutout and resets/closes when it cools back down.

 

3. What is your question #3????

 

4. This style has really had a lot of this problem and they have phased out this design, probably because of all the problems and complaints from home owners, (people don't read the manuals so how do the manufactures expect them to know to even try to clean them - user fault and really can't do much about that).  Lots of the time when you go to service one of these units it doesn't even have the LDO screen installed because whoever installed it didn't know what it even was.  If the LDO screen has been installed from the beginning and it is cleaned periodically you really don't have that much problems with the ceramic disk plugging up.

 

The newer design is much better and doesn't have the problem having to worry about cleaning, they have two areas on both sides of the water heater up much higher off the floor from all the dust and lent, (each side is about a foot square of 1/8" holes in the outer wrapper that leads down under the water heater to a flat stainless steel plate with all the smaller air intake holes kind of like the ceramic plate but just thin stainless sheet with a spring loaded trap door that has a combustion shutoff device holding the trap door open.  If you over heat the combustion chamber or have an explosive event a little glass vial breaks in the combustion shutoff device closing the trap door and cutting off the air supply.  When this happens the combustion shutoff device has to be replaced for it work again).

Edited December 16, 2013 by Budget Appliance Repair

[BryanS]

The way I've always cleaned gas hot water heaters is by removing the burner assembly, cleaning the inside, and then I used a shopvac with a bblower to blow down through the screen. Never a problem. I ran behind a lot of techs who just started replacing parts and never cleaned it. First thing I do when a pilot won't stay lit is clean it.

[Patricio]

The way I've always cleaned gas hot water heaters is by removing the burner assembly, cleaning the inside, and then I used a shopvac with a bblower to blow down through the screen. Never a problem. I ran behind a lot of techs who just started replacing parts and never cleaned it. First thing I do when a pilot won't stay lit is clean it.

Cleaning is the 1st thing I suggest to a customer on the phone when I get a call.

[BryanS]

I like that brush attachment posted. That would be nice to have and even suggest to a customer to purchase to prevent that problem.

[pjw73nh]

UPDATE: Sorry for delay folks.  OK first Where's question #3 ?  I guess I had it in there and took it out before posting and forgot to renumber.

 

Now remember the unit is at my son's house a couple of hours away so I don't get there often, but I can instruct him on what steps to take.

 

I took Patricio's advice and I have actually got some help from the manufacturer.  They too said to clean it and they sent a free wrap-around filter for the entire bottom intake area.I haven't called them back since. 

 

At this point the unit has been cleaned thoroughly several times.  Burner/pilot/thermocouple assy and lower plate removed (exposing ceramic disk).   Compressed air blown on top with extended angle nozzle, simultaneously shop vac sucking on bottom.   No debris is coming out any more.  It HAS to be cleaned by now. It will stay lit for about a 5-7 days at a time now.  Simulating an air restriction, and wobbly flame,  we wrapped a thick cloth all the way around the air intakes.  Flame goes very orange (expected).  BUT even after 5 seconds it doesn't go out.  I don't think this is a starvation issue. But what do I know.  I wish I could set a video camera up to watch the pilot and see what happens when it goes out.  

 

I still am not completely confident the main burner is drawing the pilot away from the thermocouple far enough or for a long enough time to lower its output below 20 mv. 

 

The unit is just about 10 years old, and at this point we are considering replacing it.  I hate to throw a $60 pilot/TC/igniter at it if there is little chance that this is the issue. I'd rather put the $$ toward a new unit. I certainly don't want to replace the controller. 

 

Any more suggestions on where to go with this?

 

Thanks. 

 

Paul.../NH

[electro_doc]

Personally I'd try  cleaning the thermocouple and pilot orfice.  I wouldn't put a lot of money in it though because after 10 years you pretty much are ready for a new one.  With sediment build up and corrosion.  It's different in different parts of the country but on average if you got 10 years I'd say get a new one.  It will be more efficient and probably use less gas.  It is probably a pilot, thermocouple issue though.  It's up to you if you want to invest the money in fixing this one or getting a new one.  If it was me it might depend on finances.  On the other hand it might be worth it for you just to not have to worry about it,  being it is not at your house and it is a 2 hour drive.  If you have the time it might be worth just trying to get it going better without putting in any money.

 

Doc