How to track down water leak in NL camper

My camper lives in the Seattle area normally. I moved it to Portland for the next month to act as a cabin of sorts. The water was filled yesterday (assume 60F water). The air temperature in Portland today was in the 70s. I noticed a water puddle under the hot water heater this evening right under the plumbing (never turned on, but was full). The tank itself is wet with condensation and the puddle is not large. Although the water pump was accidentally left on I don't think it's water leaking.

Do others see significant water condensation off of a cold hot water tank such that a small puddle could form?

I bypassed the tank and drained it this evening, but I'm wondering if I should look at anything else?

Good info there! I decided to add a filter to my shop air and use air pressure since that doesn't require drying time. I made a soap water solution with dawn and sprayed it on joints I fixed. I did the same for my propane connection on the stove.

If there were other leaks, I'd have had to use the dye method as the next step.

If the problem returns and you go back to leak testing, pressure (as measured whether the pump cycles) isn't always a good indicator. Before I had replumbed my outside shower and was only blowing out the lines, enough water was left in the outside shower valves that it froze and cracked the plastic, which then leaked inside under my sink.

If you decide to go the dye approach remember that amount of fluorescense is dependent on the pathlength in liquid, the type, the concentration of the chemical and the UV source.

You can test if the fluorscent approach will be sensitive enough before putting it in your water system, by placing a drop or two of your proposed solution on a plate and using your UV light source.

Instead of adding it to your water tank, replace the inlet tubing on your pump so it will fit into a gallon jug or pail. Make up the fluorescent solution. Bypass the water heater (avoids having to rinse it out and you can test it later if you don't identify the leak origin the first time). Pump it into your system.

Common food grade items that are fluorescent are:

Quinine water, aka Tonic Water; blue emission; 25 to 65 ppm (parts per million w /v grocery store 2L bottles

Riboflavin, aka vitamin B2; green emission); solubility in water 80 - 100 milligrames per liter; grind number of pills depending on dose per pill. If the pills have lots of inert filler, filter before use. We used pure riblflavin at work.


Alternately, you could just make up a 50 ppm solution of hydrogen peroxide and sanitize your water system. They make test strips (0-50 ppm and 0-100 ppm) that are easy to use by touching these to a drop of water to verify its presence or absence and whether it was from your water system or rain. After rinsing out your water system you can use the low range test strips 0-5 ppm to show the hydrogen peroxide level is reduced to a safe level. We used this at work on a USP water system.

Same approach with 5 ppm bleach and test strips could be used. We usually run with bleach at 1 ppm in our water all the time, which the test strips can detect.

3% hydrogen peroxide = 30,000 ppm
Bleach is typically 5% - 6%, actual concentration can be found on the label under active ingredient.

I noticed some water on the counter after a heavy rain as well

The window may be innocent.

We had water on the counter that looked like it came through the window. In fact it came through the kitchen fan vent. The vent flap had developed a small gap at the top, routed the water inside the camper where it entered the inner window frame from the top.

If you have a similar issue, you do not need to disassemble anything on the inside. If you decide to disassemble the kitchen fan, beware of razor sharp edges. Ask me how I know...

As we do not use the fan, we just taped the flap shut.

I think I have it all sorted out now. I replaced the city water valve, bib, and the pex elbow. Air pressure tested and held 50psi for over an hour. I then started drying with a fan for the last couple weeks. I noticed some water on the counter after a heavy rain as well as some new drips inside. So, the window is definitely a source as well. I had caulk ed it months afo with some other panels, but there was already cracking. So, I removed all caulking, cleaned with mineral spirits, and resealed. I plan on having the dealer pull and reseal the window when they can get it in later this summer.

While I was working on the water, I also swapped the stock outside shower for one of the Phoenix quick disconnect kinds and am waiting for my coil hose to come back in stock. Now I'll be able to wash a dog off from less than 2' away with no water pressure!

I'll have to check again once I get more time in, but I pressurized with water last night and turned the pump off. This morning I turned it on and heard nothing! So, it's holding pressure and no signs of water today.

Edit: I don't remember if I mentioned earlier, so in case someone is just reading the conclusion... I also found the kitchen sink faucet had the wrong gasket so it effectively could have dumped as much under the cabinet as in the sink. I saw no evidence of leaking beyond my horsing with it, but it's fixed now. As for the other work, I pulled all drawers and the oven in order to gain access. At that point, it was easy to get to everything inside where the issue was. If I hadn't pulled that, I'd never have known the issue nor been able to fix it. For those nervous about it, don't be. Mine has 6 screws and a propane line. As long as you are careful about the propane and lines, it is not a problem. LEAK TEST AFTER WORK IS COMPLETE!

I have a book that says water fill tubing plumbed down to the tank is corrugated hose and needs to be caulked inside the hose or nipple at the water fill fitting on the camper body or it leaks when filling tank w/ freshwater. I had to do mine by cutting an access door in the top of the battery box with a razor knife, I could then get to the screw clamp and take off the corrugated hose and caulk around the nipple and slide the corrugated hose back on and reclamp. I then taped up the fist size access door inside the battery box.

Mine was leaking out the jack mount bracket each time I filled up with water and this book set me on the right direction.

sorry I wasn't clearer truck campers and the areas you will be working on should be considered like confined space and require extra precautions

Do not mix bleach and ammonia.www.doh.wa.gov

Right, which is why the cleaning products I tend to use are 1:10 bleach water solutions in spray bottles. The bleach will not penetrations unless soaked in, but since the spores are the concern, bleach is my go-to. Bleach is used in pools and most municipal water sources (called chlorine) and does not generally pose a significant health risk at low dilutions. Pure bleach is a very powerful and dangerous substance that needs care but at dilutions used for cleaning products is cheap, safe, and effective.

bkenobi wrote:
I don't have other cleaning products under the cabinets. I'm not aware of a chemical reaction to metals. Do you have any details on that?

I have to use something to kill any growth as my wife is deathly allergic to mold. She didn't detect anything this morning, but I'm not taking chances.

Mold only grows in areas that stay wet for long periods of time. Once an area dries out mold does not grow. Mold actually dries out as well.

I am not sure of the surface but here is some information:

For killing mold with bleach use a ratio of one cup of bleach per gallon of water (ie about 1 part bleach to 10 parts water). Apply the solution to non-porous surfaces with mold growth either by using a spray bottle or by using a bucket and a sponge or cloth.

Bleach and vinegar can both kill mold, but vinegar is much more effective for removing mold from porous materials. This is because bleach only kills mold spores on the surface of affected materials. Vinegar will penetrate porous materials and kill the mold at the roots

I use CLR Mold and Mildew Cleaner but not sure how that would work on an unfinished wood surface.