Ultraheat Melted Black Water Tank!

[SLE]

So, I come back from fishing to a prominent sewer smell. Look under the Cedar Creek and noticed a drip from the belly pan. Figured a fitting or something was leaking. Pulled the belly pan and insulation (which was a bit of a nasty job when it's full of sewage!) and start inspecting for a leak. Notice a very slight drip coming from the tape pad that holds the Ultraheat tank heater to the tank. I reach up and touch the tank heater and notice the darn thing is hot! WTH, I get out from under and go into the RV expecting one of the kids flipped the switch on and see that everything is off as it should be. Of course I grilled everyone and nobody had touched it. I went back out, snipped the wires and pulled it off to find it melted a fairly significant hole in the tank (that sucks).

This is where it gets interesting. I pull the pan for the grey tank and touch the heater and notice it's warm but not near as hot as the one I had just removed. Go back in and check the switches to see that they are indeed still off. Start checking a few things with my limited tools and decided I must a have a short somewhere and decide to just remove the 15 amp fuse that runs the tank heaters and the monitor panel. Low and behold and hour later the damn pad is still warm! At this point, I decide I better check the galley tank. Pull the pan to find that one is cold. Well this makes some sense as this heater is on a separate switch from the other two. At this point I clip the wires to the grey tank heater and taped off all of the wires to make sure I don't burn a hole in the grey tank also.

I'll be taking the multi-meter with me back to the lake next weekend to do some checking. If anybody has any suggestions where to start I'm all ears! Second, has anybody had any luck patching a tank? I am hoping to epoxy or jb weld the hole shut as a temporary fix until I can get it home to be worked on. If anyone has some advise, feel free.

Thanks

[Ron_Nielson]

Just to make sure you have the best advice, talk to the Ultraheat people. They are helpful and it only costs a little of your time. They have lots more experience than those of us on this forum, even those who have Ultraheat pads.

I have the dual voltage pads on my tanks and have never had any problems. My understanding is that they should not get HOT and if you have something in your tank, it should never damage the tank. The pads are supposed to be thermostatically controlled, on at 44* off at 64*. Red and white wires are the 12V wires; a black electrical cord with a male plug for a receptacle would be for the 120V circuit, at least that's the way mine came from Ultraheat.

It's pretty clear that you have a wiring problem, but exactly what it is isn't clear, at least to me. My GUESS would be that it's in the 12V circuit, like maybe wired directly to the battery, but not having seen it, my opinion isn't worth much in this case.

[SLE]

Without being able to look at it I know I only clipped one set of wires and the one that melted the tank is in the trash and there were two small separate wires so it must be only 12V. Thanks for the info.

[time2roll]

This pad has both:

Pic of electric connections

[SLE]

if the description from smkettner is correct, I would lean more towards the 12V as the wires were separated and I believe they were red and white but can't recall for sure at the moment.

[time2roll]

SLE wrote:
How would I know if they are 120v, 12v, or both? Just thinking ahead before I blow the fuse in my multi-meter trouble shooting!

120v has a common black appliance zip cord.
12v has short separate red/white wires.
Some have both.

[SLE]

The hot and cold wires were separate and could be cut one at a time. Unless I ground out the hot, I don't think it would matter either way.

[Our_Place]

SLE wrote:
How would I know if they are 120v, 12v, or both? Just thinking ahead before I blow the fuse in my multi-meter trouble shooting!

If they were indeed 120v you would have noticed that just as soon as you cut the live wires! I think most of the flat heating elements are 12v.

[SLE]

We have a garden hose flush option in which we do each weekend before we leave. Works good, been doing the same for many years via our last camper.

Called the local dealer (150 miles away) and asked a few questions. He said I wasn't missing any switches and I wasn't crazy. Figured the heaters were 120v and said it should say right on the heating pad. He was as perplexed as I. Said he's never seen this. He mentioned most of the time if it shorts out it doesn't work, not get hot. If I can't fix the tank and need a new one it's a pretty spendy deal with 5 hours of labor and about $300 for the tank. please keep in mind this is in the heart of oil country where the RV dealers are booked and the economy is booming. The service guy was really nice and pretty helpful, kudos to them.

Having it on a seasonal site is really convenient until you need to work on it. I would love to have it at home to do some trouble shooting. Oh well, I'll take some tools with this weekend and some product to see if I can seal it up good. I'll report back with the findings. Feel free to keep posting if anybody has any ideas.

[Bird_Freak]

If you are leaving your black tank valve open as you said you will soon have a lot more trouble with the poop building up.

[SLE]

How would I know if they are 120v, 12v, or both? Just thinking ahead before I blow the fuse in my multi-meter trouble shooting!

[jnharley]

We found that our fuses were mislabeled. We pulled a fuse and found it did not shut off the item it was supposed to. We took lots of time checking to see what went with each fuse and printed out our own list. Now we can tell at a glance what each fuse is for. You may have the same issue with your fuses.

[SLE]

The more I think about this, does anybody know where the switches are all located for our 2008 Cedar Creek. Buying it as a used unit maybe I'm missing something? Near the Kitchen sink we have the tank level indicators and in the same panel we have a switch for the water pump and the tank heater. Both light up red when switched to on. There is also a single stand alone red switch that is simply labeled tank heater that also lights up when turned to on. Near the entry door, we have a 4 switch panel that runs 3 exterior lights and the living room lights. We also have a single switch (not labeled) that apparently is a master switch for the slides as the rocker switch for the slides won't work without this flipped to on. We also have the rocker switch that actually moves the slides in/out. Of course we have the awning switch in this location also. Out side of this area, the bathroom only has two switches below the medicine cabinet, one for the lights and one that powers the fan. I'm just wondering if There's another switch or something that powers the tank heaters that I'm missing? I may have to call cedar creek today to see how they are suppose to operate. Maybe they are perfectly fine and I just don't know how to use my camper, lol.

[time2roll]

If it is black ABS plastic I recommend Plasti-Mend. Search amazon or get direct. With a sheet of ABS any leak can be permanently fixed.

Please let us know what you find electrically. Most my UH are 120v and the circuit breaker stays off.

[SLE]

Orion, your spot on for my first plan of attack. To be honest, this is our first year with the camper so for all I know it's been doing this forever. What may have not been an issue for the previous owner may have reared its head as we hook up to facilities at our seasonal site so the sewer remains open to drain dry. I expect this is why the problem just showed up as if the tank held any water I doubt it would heat it up enough to melt it. When I pulled the fuse and it didn't shut off I was kind of baffled, so I sat back and poured a whiskey and thought about it for a while, lol.