22rifle

One of my co-workers had no hot water so I offered to check it out for him. His plumber had installed a 30 gal NG American WH around a year ago.

Could not get the pilot light to stay lit. Check the thermocouple with my little gizmo and a multi-meter. Tested OK. (Y'all use that little gizmo don't you? it goes between the thermocouple and the gas valve.)

I had a thermocouple left over from when I was in the business and had it along so he asked if he pays for it, if I would replace it anyways. Told him I don't swap parts to diagnose but hey, it's his money. Well guess what? it worked. But only for about 5 minutes. Then I couldn't get the pilot light to stay lit again. Checked the millivolts with my gizmo and it tested fine.

I ain't asking for help here. He really wants a new water heater after the reviews he found online about this model. Of course, I educated him on which brand to get. (NOT American for sure.) He is calling a plumber I recommended on Monday.

But now that I am home this is bugging me. The gas pressure checked out fine. (Manometer) The pilot light is nice and strong. Am I missing something or is the valve just bad? I don't "need" the answer like I said. It's just bugging me. All these years I prided myself on definitive diagnostics. It's been awhile since I did service. Maybe I am just rusty. But it BUGS me! LOL

BTW, the same plumber was telling them that a Bosch tankless was the best option because it was cheap and because Lowe's wouldn't carry something unless it was the best. I explained a few things to them.

Man, I love what I do but I sure did enjoy using my skills and tools again. It's hard to beat plumbing service work for being fulfilling.

TheMaster

Could be just a bad magnet assembly or high limit in the control valve.....either way on that heater it would need a new control. Was it the flame lock heater? Pilot light was burning blue and the tip in the flame?

Plumber Jim

They had a bad batch of gas valves. I bet it just needs a new gas valve. from what i hear they had like 3 semi truck loads of bad valves that have been going out.

SewerRatz

Was it one of the sealed combustion FVIR type heaters? Only a year old it should of been.

So I am going to assume it was. Where is the water heater located? Same room as the washer and dryer, or a room where lots of dust is around the heater? Here is the trouble I have been running into no matter what brand is installed. The FVIR system pulls in the combustion air in through the vents on the side or bottom of the water heater and through the fine mesh screen. Over time lint, and dust gets sucked right on in and chokes off the fresh air intake. Once this happens no matter how much you can vacuum out the unit it is toast.


One way to tell is lay on your side and watch the flame, if it starts to roll or just does not look normal, that is a good indication. Then to conform this is remove the screws securing the sealed door and pull it open a little to allow air to get drawn in and see how long it stays lit this time.

__________________
Ron Hasil Lic #058-160417
A-Archer Sewer & Plumbing specializing in:
Tankless Water Heaters | Drain and Sewer Cleaning
Sump and Ejector Pumps | Backflow RPZ Testing

22rifle

It was the FIVR and the pilot light flame was perfect as was the burner flame. I check that stuff by instinct, almost.

About the time FIVR came out I stitched to new construction so I never serviced them much.

Are gas valves considered a replaceable item on FIVR WH's? This one won't be replaced. He has his mind made up. I am just curious.

SewerRatz

Yes they are replaceable. Even if you have an older non-FIVR unit the new gas valves have the wires for the FIVR, but has a jumper to bypass the heat sensor.

I have had some with perfect flames that died out right away, but when I cracked open the door they ran fine. Ended up replacing them under warranty.

__________________
Ron Hasil Lic #058-160417
A-Archer Sewer & Plumbing specializing in:
Tankless Water Heaters | Drain and Sewer Cleaning
Sump and Ejector Pumps | Backflow RPZ Testing

TheMaster

Yes you can replace the gas control on a FIVR. I think american water heater controls have left hand threads on the thremocouple connection or some of them did anyway. Rheem's FIVR also has a door that slams shut to prevent extended vapor burns in the burn chamber...once it acts the heatr must be replaced...technically. You can change the gas control although on all of them.

22rifle

So is it technically possible to recondition a "blown" FIVR WH?

Or is the reason it's shot strictly liability issues?

Please understand, this is coming from a guy who even refused to install used gas water heaters for safety and liability reasons. If the manufacturer says it's a one time deal and to replace it, only a fool would assume the liability of reconditioning it.

(I fee like I have to put all these disclaimers in because a lot of the newer crowd on here doesn't know me and my passion for plumbing and for doing right. Those who know me well would know I would never do something like this and that I am just curious.)

TheMaster

You can replace the gas control on any of them.......however rheem's have a one shot safety door in the bottom of the heater and if it "acts" the heater must be replaced.......its a glass vile filled with oil...if the heater overheats or theres a fammable vapor burn in the combustion chamber the oil will expand in the glass vile and rupture......the spring-loaded door will slam shut and cut the air off to the heater. Technically you must replace the heater at that point.

22rifle

I am familiar with how Rheem's works. But theoretically couldn't you replace the glass vial, etc? Sorry, I don't mean to be a pain. Just hashing it out in my own mind.

If you could repalce the glass vial and reset it, then why don't they allow you to do it? The answer to that will teach one a lot about the whole set up.

My dad taught me the biz. One of the ways he taught me was to tear stuff apart. A lot of times we would experiment in our shop with stuff we replaced for a customer. In doing so, I not only learned WHAT something did, but HOW and WHY. I remember taking sprinkler heads that we tore out of a job and heating the fusible links with various heat sources to see what made them melt. Stuff like that.

That's the kind of thinking that drives my questions.

Sorry if I am a pain.