Atwood gas water heater inop

mmulroy · 08-27-2023, 09:53 PM

I have a GCH6A-10E Atwood gas water heater that was inop. After reading some of the articles here, I diagnosed an open THermal Fuse. Replaced the fuse, cleaned the igniter, and checked for other obstructions in the outlet tube. turned the switch on and the unit fires up but only produces a small flame that rose up to the thermal fuse. THe flame immediately goes out and the system goes into fail safe mode. I expected a blue flame that would push itself further down the outlet tube. I believe my gas flow is way too slow. Do you think that the Gas pressure regulator is the culprit?

Morich · 08-28-2023, 07:54 AM

That would seem suspect but there may be other things to look over?
No chance the gas tubing is damaged like a crimp that would block flow? Also can you get a look at the orifice?
The orifice is a small brass fitting at the end of the tubing where the fire lights. Think of it as the nozzle if we were using a hose? If something gets in that tiny little hole in the orifice, it can change the gas flow.
Mod dauber, or corrosion of some kind, even though it is brass? Maybe a thin wire pushed carefully in to verify it is open? Maybe a small fleck of dirt/rust from something along the line?
I say carefully because brass is not too hard to deform if we get too rough, so not like run a drill in the hole!! If it comes off easy, it can be safer to pull it out and look but it IS a tiny little precision hole!
Cheaper than replacing the reg? Any chance a local propane dealer might check the pressure on the reg for a small price?

Just reading some other posts brings a question. Are you sure there is not a nest of some type blocking the airflow past the fire? part of the operation is that the flow draws the flame in. Wasps building paper nests in that tube is a common item, if you have not screened it! They may build where you can see it or way back from the inlet and hide. It's just a tough metal tube, so running something like a coat hanger fully in that tube may be worth doing.
They have a nasty habit of builin it to the shape and it really does a good job of blocking air and sounds like what you might be seeing on the flame as it is not the full blown flame due to lack of good air??

Good luck on the search!

mikf · 08-28-2023, 09:09 AM

What do you mean, flame went up to thermal fuse? The thermal fuse is not in the fire chamber. The flame goes up to the flame sensor. Did you take the flame sensor out and clean it?

Ray,IN · 08-28-2023, 09:03 PM

Sounds like a spider has built a nest in the LP orifice(spiders love propane odor). You can use a toothpick and compressed air to clean it out, but do not use anything metal, it will damage the soft brass orifice.

The thermal fuse is outside the burner area, and will only break when there is a large fire flashback from the burner. If it is broken there will never be a flame.
Just for the sake of covering all bases; is your LP tank/cylinder full? If it is,, turn off the flow knob, wait a minute then slooowly open it and light the WH again.

mmulroy · 08-29-2023, 07:18 AM

Based on a maintenance video I found in the forum, I removed the igniter and flame tube. inspected the tube, adjusted the igniter, removed the gas nozzle for inspection, reinstalled the nozzle, reinstalled the flame tube and igniter. I did not adjust the air flow because the system did work in the past. Fired up the unit. 3 click, gas lights in the tube but the flame is silent and it rose out of the tube. seems like no pressure from the gas regulator. A very slow burning flame that went out in 5 seconds.

mikf · 08-29-2023, 07:23 AM

does your frig work ok on propane? Does your stove have a good flame? If not you may need a new regulator. You should have cleaned the flame sensor with very fine sand paper when you had it out,

Ray,IN · 08-29-2023, 03:24 PM

Quote:

Originally Posted by mmulroy

Based on a maintenance video I found in the forum, I removed the igniter and flame tube. inspected the tube, adjusted the igniter, removed the gas nozzle for inspection, reinstalled the nozzle, reinstalled the flame tube and igniter. I did not adjust the air flow because the system did work in the past. Fired up the unit. 3 click, gas lights in the tube but the flame is silent and it rose out of the tube. seems like no pressure from the gas regulator. A very slow burning flame that went out in 5 seconds.

That is the classic symptom of the excess-flow feature in the tank valve closing. Close tank valve, wait 5-7 minutes then open very slooowly and smoothly. Then if it happens again, the regulator or the hose is the next suspect.

mmulroy · 08-29-2023, 09:48 PM

Mike I don't know anything about a flame sensor. The thermal fuse was definitely bad. I did have the nozzle out but was told to inspect it only. The material is too soft to sand or poke a bigger hole. The flames on my stove are all fine and the refrigerator run fine on propane. I just think that there is not enough of a high rate of propane flow when it turns on. I'll try the shut off - turn on technique Ray recommended and then go from there. Thanks guys!
Mark

powercat_ras · 08-29-2023, 10:35 PM

You could try the RV propane furnace it requires an even bigger propane gas flow than the water heater does. That might allow you to rule out the RV propane regulator as a potential problem.

If the gas flow seems to be good then another potential point of failure is the 12 volt propane gas valve it could have some contaminant in it that is preventing it from fully opening.

mikf · 08-30-2023, 07:07 AM

Atwood 93868 Water Heater Replacement Parts - Spark & Sensor Electrode. The straight part is the sensor. If it is defective or has the slightest amount of residue on it the flame will not stay lit. Normally a good cleaning is all you need. Your propane frig works the same way. Good Luck

Bobn1957 · 09-03-2023, 05:18 PM

Hello, if the stove works with all the burners lit and the fridge works I would deduce that your problem is with the water heater and having replaced the fuse, and cleaned the burner the only thing left is the control valve. It's probably not serviceable so you would be left with replacement.

Morich · 09-03-2023, 05:45 PM

One of the best ways to save money on DIY work is to get the best troubleshooting I can find. That is often NOT forums or the internet.
Not to belittle anybody here and most of us do try to give the best advise we know.
HOWEVER? Not many of us know as much about any frig as the folks who build them and work on them every day!

So I favor getting the correct brand and model number off the frig and doing a search for a troubleshooting flow chart!

This is one which I find handy for lots of problems as it has lots of those small points that help a novice repair person. Things like pictures of the different parts can be very helpful!!

http://techsupport.pdxrvwholesale.co...ter-Manual.pdf

Since it appears you have an electronic ignition model, perhaps start at page 17?

mmulroy · 09-05-2023, 08:04 AM

Thanks for the replies. All my appliances are working well on gas except for the hot water heater. I now have an excellent electric water but the gas part is the problem. I didn't realize that the electrode to the the ignitor was a sensor. I'll clean that really good. After that it could only be the control valve. Thank!

Morich · 09-05-2023, 09:56 AM

Yes! Safety item that acts to cut off gas flow if the fire goes out for some reason. Good idea to not fill it with gas and then it suddenly explode!

mikf · 09-05-2023, 03:14 PM

Quote:

Originally Posted by Morich

One of the best ways to save money on DIY work is to get the best troubleshooting I can find. That is often NOT forums or the internet.
Not to belittle anybody here and most of us do try to give the best advise we know.
HOWEVER? Not many of us know as much about any frig as the folks who build them and work on them every day!

So I favor getting the correct brand and model number off the frig and doing a search for a troubleshooting flow chart!

This is one which I find handy for lots of problems as it has lots of those small points that help a novice repair person. Things like pictures of the different parts can be very helpful!!

http://techsupport.pdxrvwholesale.co...ter-Manual.pdf

Since it appears you have an electronic ignition model, perhaps start at page 17?

I agree with your point about using forums to fix problems, but if you filter the responses I have learned a lot on these forums.

mmulroy · 09-05-2023, 09:41 PM

Last words on my gas heater. I took the ignitor out, cleaned the grounding rod, blew out the exhaust pipe with high compressed air. The exhaust had lots of soot in it. I did find an old cob web inside the gas tube before the the ignitor. Blew out the tube. Reconnected the assembly, fired it up, adjusted the flame to be less noisy and more efficient. Bottom line, between the thermal fuse being out and the entire gas unit needing some maintenance and adjustments, both electric and gas heater are working like a boss. Thanks for all your suggestions. Hope to see you around, Mark.

mikf · 09-06-2023, 05:26 AM

Quote:

Originally Posted by mmulroy

Last words on my gas heater. I took the ignitor out, cleaned the grounding rod, blew out the exhaust pipe with high compressed air. The exhaust had lots of soot in it. I did find an old cob web inside the gas tube before the the ignitor. Blew out the tube. Reconnected the assembly, fired it up, adjusted the flame to be less noisy and more efficient. Bottom line, between the thermal fuse being out and the entire gas unit needing some maintenance and adjustments, both electric and gas heater are working like a boss. Thanks for all your suggestions. Hope to see you around, Mark.

Thanks for the update. Now you should clean the burner assembly on your refrigerator before you have a problem with that.