This may have been self inflicted water heater

[BobinICT]

First off, specs. Dinosaur UIB 64 installed over a year ago. Situation. Had the leak down test done. Got around to purging the propane lines as far as I could go, took a little while for the three burners on the stove to light. Put the fridge on propane, all good so far. Flip the switch for gas on the water heater, listen for the light. No light, DSI light on. Off and on again, again and again. Getting hot. Went back out after a few hours and turned on the AC, on shore power. Now cool enough the stand there inside and cycle the on off switch. I'm about 30 to 40 times, on, off. In quick recession. Finally get a no DSI light. Good, we have a fire. Go out and around. Smell burning something. Plastic? Wiring? Open WH cover and find this. No fire anymore in the burner area, thermal link toast.

So, did I violate procedure and create my own problem? Is there something I should check before replacing the thermal link before attempting a relight?

Feel like I'm reliving the flameout in the Huey at 10,000 and in autoroation and get a relight at about 5,000.

[Country Campers]

If you are sure the thermal link is bad then you will need to replace it. Yes I believe that you caused this issue by turning the heater on and off and getting a little propane each time filling the chamber and then causing the event ( see I did not say burst into flames, whoops). I am not sure if the Dino board will still be good.

Brian

PS: Love the autorotate analogy.

[Jlawles2]

I'm tempted to ask if you have an obstruction in the flame chamber or exhaust.

Yes cycling the switch is BAD, but a quick fireball would have made a loud noise, and possibly caused some heat damage, but that looks more like sustained heat.

[BobinICT]

I'm tempted to ask if you have an obstruction in the flame chamber or exhaust.

Yes cycling the switch is BAD, but a quick fireball would have made a loud noise, and possibly caused some heat damage, but that looks more like sustained heat.

The board survived, thermal link didn't. I have removed, inspected and confirmed there are no obstructions in the chamber or gas tube leading from the gas orifice by removing, cleaning and a small wire in the orifice. I did discover like the OEM board, it will attempt a light three times before it times out. Igniter is functioning. Wondering if I have an obstruction preventing gas flow as a result of the leak down test. I SO want to slide the air shutter out of the way and see when it cycles if I can get a flame at the orifice but I'm not in the mood for a flame thrower today. Thinking I'll go to Lowe's, buy a sniffer and, (be a bad boy and return it when I'm done with it). I spend enough money there.

I was inside with the AC running so I was unable to hear anything like a fireball or such. Other than the plastic cover that melted, I don't see any additional damage so I'm confident there was no additional fire damage.

[howson]

BobinICT -- can you be more specific about what is meant by the "leak down test" (in your words)? If it's what I think it means, I'm curious as to why it was done as a standalone test. Was the regulator's Water Column output tested under load?

[BobinICT]

BobinICT -- can you be more specific about what is meant by the "leak down test" (in your words)? If it's what I think it means, I'm curious as to why it was done as a standalone test. Was the regulator's Water Column output tested under load?

The test was required by GD for when they sent me the replacement regulator for the recall. The RV repair place I took it to knew all about preforming a leak down. As for "under load". I believe whatever the procedure it was he did it. He explained it to me when I made the appointment. If I remember correctly, something like they run the stove at full pressure then draw down and preform the test or, something to that effect.

I did buy a sniffer at Manards and I think I will keep it. The wind has come up so I need to wait until morning when the winds are calmer because the rig has a direct side wind and I feel testing for propane would be worthless. Besides, it's 105 out there now and direct sun to that side as well.

[howson]

BobinICT OK, they probably did a check with a manometer to ensure there was 11" WC (water column) of propane at the output of the regulator. This is done correctly with a "50% load" (or 1/2 of the possible 100% draw if everything that used propane was on at once).

For "leak down", what that probably means is they checked for leaks after installing the new regulator. The proper way to do this is pressure the system, close the tank valves, then reduce the WC on the manometer to around 8" of WC (I forget the exact value but that's close). Over 5 minutes the manometer is then monitored to ensure it does not change value. Any change = leak.

So...all that write my guess is it's doubtful there's a leak sufficient from the system that would affect the firing of the water heater that your sniffer wouldn't detect.

Look forward to reading the resolution to the issue with the water heater.

Howard

[BobinICT]

BobinICT OK, they probably did a check with a manometer to ensure there was 11" WC (water column) of propane at the output of the regulator. This is done correctly with a "50% load" (or 1/2 of the possible 100% draw if everything that used propane was on at once).

For "leak down", what that probably means is they checked for leaks after installing the new regulator. The proper way to do this is pressure the system, close the tank valves, then reduce the WC on the manometer to around 8" of WC (I forget the exact value but that's close). Over 5 minutes the manometer is then monitored to ensure it does not change value. Any change = leak.

So...all that write my guess is it's doubtful there's a leak sufficient from the system that would affect the firing of the water heater that your sniffer wouldn't detect.

Look forward to reading the resolution to the issue with the water heater.

Howard

Yes Howard. That pretty much sounds like the way it was explained to me. Apparently I DID have gas at one point. I'll continue to mess with it when its cooler out and report back. I'm thinking I may remove the orifice and turn it one and see if that might blow out accumulated oil perhaps. In fact, a windy day just may be the conditions I need to disburse the propane if it discharges now that I think about it.

[Jlawles2]

I've used this to track down gas leaks before. https://www.homedepot.com/p/Oatey-8-...2092/100151681 That funny blue water will bubble like you would not believe.

[BobinICT]

Got it fixed. Messed with wire connections at the solenoid but couldn't the connections to budge. The blade connectors must have been squeezed at the factory. Removed the heat blasted plastic cover and disconnected, cleaned the connectors and reinstalled after removing the board for inspection. There was a little of black soot that wafted up during the blast so I cleaned that up as well. Got a hit on the sniffer. Preformed a field expedient repair on the cover and reinstalled everything. Got a light on the first try. Checked the flame and a good blue flame in the chamber.

[BobinICT]

Well, I'm back with the same issue. Can't get the water heater to lite. I have cycled the switch, slowly this time and even let it cycle on its own for the initial lite attempt and the two relite attempts that are spaced one minute apart.

What I've done so far. Was checking systems after having sat since early July. Purged the water system and checked for leaks among other things. Attempted to light the water heater yesterday afternoon. No lite. Went to the stove and fired up all three burners. In doing so, had air at first then they lit. OK, I'm thinking I've purged the gas line now. Still no lite. On and off for at least 50 times, no joy. Before calling it quits for the day I started the fridge on gas, that took two attempts and it lit. Figured I'd let it run overnight and hopefully get more air out. Fridge this morning was good and cold just like it should be. Attempted to lite the water heater this morning, same thing. Took the sniffer out and during a attempted relite checked for gas at the opening of the fire chamber. It didn't sound off. Checked the sniffer at the stove but just turning on one burner and got the warning so sniffer works. Pulled the thermal link and tested it, good. Fired up the furnace to check it anyway and burn off the dust. Still not getting a heater lite.

Last time it didn't take so many cycles to get it going.

Strange thing is, I've had the propane connected the whole time and the tanks on with the exception of removing one to get it filled so the air in the lines is a misery. The water heater worked just fine in May, June and July. Oh and, I did test the electrical heater and it is heating. Did that yesterday while I was cycling the switch.

So, I'm at a loss currently what to do next. As stated above, any attempt to check the wire connections to the gas solenoid are a no go, they are on tight!

[TedS]

Sounds like the solenoid gas valve on the water heater is not working. Sniffer did not detect gas.

[howson]

BobinICT -- I've read about oil getting into propane lines (I haven't seen it myself) but I wonder if that could be related to the issue. This article appears to explain the cause and fix well: https://blog.goodsam.com/rv-doctor-propane-lines/

The water heater line is the first that branches off of the main line. That may or may not mean anything.

And no, I can't explain how the oil could only affect this one system. (Admittedly I'm spitballing here.)



Howard

[BobinICT]

Well, I did a YouTube search and found a couple of things to check. Before that, I went down the street and borrowed the neighbors gorilla and was able to break loose the gas connection to the valve system. I verified I did in fact have clean gas flow. Then I started to check voltage to the solenoid gas valve and found I was only getting 10.65 volts when it attempted a refire. So, I checked the two thermostats that the wires plug into and both had continuity, removed each one to inspect behind as there could have been dirt behind them or something. Long story short, after reinstalling them I was disconnecting the thermal wire and reconnecting to force a refire rather than wait a whole minute while checking voltages. Well, that blew one and the board went dark.

I'm cutting to the chase and ordering a new Dinosaur UIB 64 board and replacement thermostats. They'll be here Monday. I suspect one or more of the components were weak and going out, considering the abuse the Dinosaur UIB 64 got last time.

Rather this happened now and not on the road. That's why I am so adamant about checking systems. Bust it if it's going to bust it while not in flight.

I'll update once the components have been installed. Now on to washing and waxing the rig.

Oh, one other point. I found out why the connections are so tight to the solenoid valves. They are hard soldered. Duh

[BobinICT]

Fire in the hole! But, not right away.

Received the replacement thermostats and board. Installed both, go in and hit the switch. Hear clicking, light flashing with the clicking. Now what? I'm starting to feel like Mark Martin, if it wasn't for bad luck, I wouldn't have any luck at all. Reinstall the original Dinosaur board and back to no lite.

So there's ONLY one electrical component left to replace. Yes, TedS the solenoid gas valve. Call a local trailer place and the parts guy gives me news I didn't want to hear. After cross referencing part numbers based on the model of the water heater he comes up with a replacement one this while telling me the story of Dometic having bought out Atwood, and, the big Texas freeze a few years ago, they are no longer making the Dometic style that is in our rig, and, they are no longer making replacement parts for said type of heater but, there are some knockoff brands in the supply train. He did have what I needed but it would be $275 before tax and he right out said I could find one much cheaper online.

Armed with the part number he gave me I of course went to Amazon and a few other places. Settled on the Amazon one for $128 and decided might as well roll the dice. It only has like four reviews so I'm just hoping for the best.

It came in the next day. The photo on Amazon shows just the valve with no brass fittings. No problem, I have that gorilla down the street. Open the package up and lo and behold, it has fittings! And, the slip of paper is actually from Dometic. Great, no need for the gorilla, besides, they eat a lot to boot.

Install the valve, bleed air at the connection to the valve and tighten it up. Hit the switch, fired right up. Do the soap test at the connection and all is good. Return the replacement board and all is fixed.

I have to wonder if it has been the valve since we got the rig at one year old and it was intermittent the whole time as we have had fails from time to time even after installing the Dinosaur board. Who knows.

Thanks for all the help and insight on this and hopefully this endeavor will help someone later on.