Ammonia Conundrum

Shortly after arriving home a few weeks ago with my 2005 2720SL, I had just backed it into the garage. As i walked around the passenger side of the trailer, i got a faint whiff of ammonia. The trailer had come to us after a nasty mice infestation (and a live mouse), and we had been doing a lot of cleaning. So i figured it was probably a little left over chemical that had spilled somewhere. The next time i backed it in the garage, i got the same odor. I looked around for the bottle of ammonia that i'd run over, but it was nowhere to be found. This has been the case now for much of the last month. Everytime i back the trailer into the garage...a faint smell of ammonia. That's the only time i ever get the smell of ammonia. It never is noticable inside or out of the trailer when the trailer is out of the garage. It dissappears quickly once the trailer is inside. After some research on this board and around, I discovered that ammonia is a prominent part of the refregerator brew. I quickly resigned myself to replacing either the cooling unit ($400 from the Amish) or the entire Norcold N300 ($900) and starting dropping clues to my wife...."I'm smelling a little ammonia around the trailer", and "turns out the refrigerator runs on ammonia" so the shock wouldn't be completely unexpected. Fortunately, she had decided that we would purchase the trailer so this was going to be a little less painful. (As a side note, we were out looking for Tent trailers. When we looked at one guy's Coleman, i asked him why he was selling it. He said: Cuase i upgraded to that...and he pointed to a Trailmanor parked next to his house. I'd never seen one, and didn't pay much attention to it, but as we drove away my wife said: "what's a Trailmanor?" If that guy had kept his mouth shut, we'd probably own his old Coleman now). Back to the problem at hand. I pulled the TM out of the garage last night, turned the frig on to propane. and listened for the expected 'gurgling noise' of impending frig death. No noise. 2 hours later the freezer was at 10 degrees. I put the frig on AC and left it overnight. This morning the center of the frig box was 30 degrees. No gurgling, no ammonia smell, no temperature problem. Any ideas? Does anybody know of a way to identify an ammonia leak besides smell or observation? I've looked all around the frig in and out, and don't see or smell anything.

[ShrimpBurrito]

The smell of ammonia is definitely a classic sign of a cooling unit leak. I'm no expert, but I wouldn't be surprised if, even if you had a leak, it would still initially cool. But it wouldn't stay that way, and my guess is would warm up again within no more than a few days, less if it were hot outside.

I believe a yellow residue will often appear on the cooling unit of a fridge that has leaked. Pull off the two vents on the outside of the TM that cover the back of the fridge and you'll see all the metal tubes running all over the place. That entire maze of metal tubing is the cooling unit, and some of it is probably covered in insulation. Check all around there for yellow, peaking behind the insulated areas as well. If you see any, the cooling unit is shot and cannot be fixed.

Dave

thanks Dave, i'll take a look.

[B_and_D]

We live out in the country and have had to deal with BIG rat nests in the willows. Once the kids abandoned their tree fort, the rats took over so fast that it was one huge pile of rat nest sticks and rat excrement.

The rat excrement tends to have an ammonia smell, kind of like dirty diapers except it's much, much worse.

Not to get your hopes up, but maybe you're just smelling left over mouse excrement.

[Barb&Tim]

Since the fridge seems to be cooling properly, i doubt that you have a leak. I would look elsewhere for the smell.

Tim

B&D, thanks for the ray of hope! That reminded me that the entire trailer did smell of ammonia when we first recieved it. We disinfected it with cleaner and bleach, and it still smelled horrible. We ended up using a chemical for pet urine that breaks the residue down and it got ride of most of the problem. The last bastion of stink was the oven. The mice had gotten into the insulation between the outer and inner shell and lived there. I had to pull it out and disassemble the entire oven down to the last pieces, disinfect it, and replace all the insulation. But there may be a spot near exterior where there is still some mouse pee pee. The whole infestation might have happened over a short period of time, there is no evidence of any fabric or wiring damage. It's the danger of a long distance transaction! At least the seller chipped in $500 for the cost to clean it up.

Ammonia detectors DO exist. My former blueprinting company used a lot of ammonia to develop blueprints.

A cheap and fun way to check for leaks is with some blueprint paper.
Check in the yellow pages under "blueprinting" or "reprographics". Start calling the closest ones and ask if they still develop blueprints with ammonia, and if so can you buy some sheets to find ammonia leak(s).
A couple decades ago I would have charged about $3 for 10 sheets of 24"x36" paper. Also ask if you need to bring a tube to put it in or if they have extra black bags that it comes in. The tube must be light-proof, caps can be duct tape. Diazo paper is available online also, but I haven't found small quantities for sale.

Technically "blueprints" were blue with white lines. Modern diazo chemistry makes blue or black lines (blueline or blackline) on white paper for easy reading and notes. (Redline and brownline were also available but cost alot more.) The industry has mostly moved to LED printer/xerox process on uncoated paper. But they are all still called "blueprints".

How it works for printing : The sheets start as white paper with a yellow coating on one side. The original drawing (on translucent material) is placed square on the paper then exposed to bright UV light. At this point the paper will be mostly white with yellow lines copying the original. Then the paper is run thru strong ammonia to develop into blue (or black) lines on white paper.

How you can use it for detecting ammonia leaks: Just get the unexposed paper near any ammonia and it will quickly change color. You can wrap pipes or sections of the fridge with the paper to locate leaks. Ammonia quickly goes thru the paper - so you can have the yellow side out to see color changes.
Warning: the paper is very sensitive to light. In direct sunlight it will expose and be useless to you in a few seconds. Inside in office light 10-60 minutes. SO, do this at night or in a dim garage.

To find "pee pee" you could stick some pieces of the paper at cracks, openings, cabinets, furniture, etc. Then leave it in dark (or cover with cardboard) for a few days/weeks to find trace ammonia.



Fun with extra paper: Cut or rip a piece larger than you hands. Hold firmly between your hands and spread your fingers. Step out into sunlight and expose yellow side until it turns white. Keep your hands on the paper until you get back inside. Develop the shadow picture by rolling up and holding over a bottle of household ammonia. A plastic tube with the paper held over the ammonia is less stinky.

Kids like to lay things on the paper in a bright room and in a few hours the paper will expose. Then develop it.
Also they can slide a sheet over the top of the ammonia bottle to "draw".
.

"Fun with extra paper": or just pee on it to see what happens! Thanks for the suggestion, i called a friend of mine who owns a print shop. He said it's hard to find that paper..."old school"... but he's going to check around.