Suburban water heater problem on gas operation

[kenandterry]

I have a Suburban SW10DE water heater which can operate on electric and/or propane. Recently, it started to fail running on propane. Now when I turn on the propane switch inside at my control panel, it illuminates the red lamp, I hear the click, I see and hear the flame outside operate, but after a few seconds, it all stops. As described in the manual, it does the same sequence 3 times and then stops completely.

I removed the "motherboard" and had it tested at a local RV repair centre, and they reported all works fine. I cleaned all the contacts of the plug and connector, and re-installed the "motherboard". I cleaned the gas orifice tube, cleaned out the chamber where the flame occurs, and re-assembled. The next day, everything ran fine for several hours.

Next day, the red lamp was on, and no hot water. I turned off the propane switch, waited several minutes and turned on the switch, and I'm back to the same problem outlined in my first paragraph.

Anyone have any ideas before I'm at the mercy $$ of an RV serviceman?

BTW..the electrical side of the operation works fine.

Thanks in advance.

[SeaDog]

I was leaning toward the high limit switch, but if it works on electric sort of rules that out. You might want to check the gas pressure at the valve with a manometer and ensure you are getting proper pressure.

[WY Husker Fan]

The flame proving function of the control is not sensing the flame. Try cleaning the electrode at the spark with very fine emery cloth or steel wool. The spark electrode functions as the flame sense probe by utilizing the fact that the flame is conductive but if there is any corrosion on the electrode it will not conduct.

[OldCoot]

The igniter wire has to be in alignment in 3 directions for the burner to work properly. It may light, but will not stay lighted. Page 12.

[Grampa Jim]

KenandTerry.....being as I was in the appliance repair business for 40 years, I can point you right to your problem. There is a sensor in the flame that has microscopic soot on it. Take it out and clean it with steel wool. Your problem will be solved. It doesn't take much soot to block the flame sensing. It'll fix you up.

[jimsara]

Are you at high altitude? I believe that the instructions indicate that over 4500 feet or so operation on propane may be affected.

[I Simpson]

Originally Posted by kenandterry

I have a Suburban SW10DE water heater which can operate on electric and/or propane. Recently, it started to fail running on propane. Now when I turn on the propane switch inside at my control panel, it illuminates the red lamp, I hear the click, I see and hear the flame outside operate, but after a few seconds, it all stops. As described in the manual, it does the same sequence 3 times and then stops completely.

I removed the "motherboard" and had it tested at a local RV repair centre, and they reported all works fine. I cleaned all the contacts of the plug and connector, and re-installed the "motherboard". I cleaned the gas orifice tube, cleaned out the chamber where the flame occurs, and re-assembled. The next day, everything ran fine for several hours.

Next day, the red lamp was on, and no hot water. I turned off the propane switch, waited several minutes and turned on the switch, and I'm back to the same problem outlined in my first paragraph.

Anyone have any ideas before I'm at the mercy $$ of an RV serviceman?

BTW..the electrical side of the operation works fine.

Thanks in advance.

Checj for soiderwebs in the venturi.

[Danesville]

Just the flame sensor , replace it and that should solve the problem. Happy Camping

[kenandterry]

Well now I have this problem.....

I removed the entire burner assembly and manifold outlet. Then I removed the electrode, and cleaned the end pieces with steel wool. The gap between the spark electrodes was 1/8". I reinstalled all the pieces, put lubricant on the threads of all the nuts and bolts for assembly.

Went inside, and turned on the switch for the gas to the water heater......and nothing. No light, no clicking, no flame. Nothing.

At least lights, clicking and flames happened before cycling 3 times before shutdown.

What did I break now?

[wmtire]

Originally Posted by kenandterry

Well now I have this problem.....

I removed the entire burner assembly and manifold outlet. Then I removed the electrode, and cleaned the end pieces with steel wool. The gap between the spark electrodes was 1/8". I reinstalled all the pieces, put lubricant on the threads of all the nuts and bolts for assembly.

Went inside, and turned on the switch for the gas to the water heater......and nothing. No light, no clicking, no flame. Nothing.

At least lights, clicking and flames happened before cycling 3 times before shutdown.

What did I break now?

Assuming you do have water in the tank (always make sure before trying to use the water heater)

That is going to be hard to really diagnose, as to what you may not have reassembled correctly. I would start with the easiest, and make sure you made the electrical connection to the electrode correct (The rusty orange wire) in the bttom right hand side of the pic below.

Then push the ECO/hi limit reset buttons under the rubber covers, to make sure one or both have not tripped.

[donniedu]

Originally Posted by SeaDog

I was leaning toward the high limit switch, but if it works on electric sort of rules that out. You might want to check the gas pressure at the valve with a manometer and ensure you are getting proper pressure.

Not necessairly. There are two seperate limit packs. One is 120VAC, which is on the left side. The second one is 12VDC. Which is used when using propane. To check the limit switch packs, remove the rubber cover which is about mid height on the left side of the heater. Using an ohm meter check for contunity.
Using compressed air set at about 25PSI be sure to blow out the orifice tube too.

[rvdoctor]

Make sure the ceramic on the ignitor is not cracked or loose and connections are clean tight. I've also seen power boards pass bench test and still not work when installed on the unit. Remove reset button cover, check tsat, and eco connections. You can bypass the eco and tsat with a jumper wire to see if that is the problem. Just make sure you don't bypass for more than a couple of minutes.

[kenandterry]

Our cell and Internet service is minimal at best over the next few days as we travel.

I have full operation of the electric circuit for the water heater for the rest of the road trip.

I'll update and continue working on my propane problems with the water heater when I get home.

Thanks for everyone's input and suggestions so far, and I'll get back to you all soon.

[kenandterry]

Okay.

Back on the Homefront. Didn't do any work at all to the water heater.

Now when I start the water heater using propane, I turn on the switch, the interior red light lights for a few seconds, the light goes out, the burner fires up and it heats the water. So....when I started this thread, I had a propane problem with the water heater. No I don't?

The flame is pretty much a blue colour, so that's good. Not sure if it's the hottest flame available, but I do hear the roar of the burner. Is it necessary to have a professional repair person judge if it's burning 100% correctly?

I can't fix what's not broke right?

[donniedu]

Altitude issue?

[Grampa Jim]

kenandterry,,,,,sounds like it's running normal.....yes, a blue flame,,,,yes, a dull roar,,,,yes, hot water.

[rockfordroo]

Originally Posted by donniedu

Altitude issue?

X2 - recent thread about fridge not working above 9000 ft. Where were you when you were having problems? Was your fridge running OK on gas?

[kenandterry]

We were just touring around Northern Ontario when the propane water heater trouble started so elevation is not an issue. And yes, all other propane appliances worked fine on full tank.

Just one of those things I guess.