Fixing the Fridge, Again!

The fridge broke again.  Sigh.

As I've mentioned before, this is a Norcold Gas Absorption Refrigerator model 6162.  It works by heating a loop of ammonia - pressurized so it is liquid at steady state but transforms to a gas when heat is added.  Our fridge is a 2-way, which means the heat comes in the form of either AC heating element or an LP gas flame.  (3-way versions are slightly more expensive and feature a DC powered heater, typically hooked up to the chassis battery.  This is nice because it means you don't need to run the generator or use LP gas, but it quickly drains the battery.)

Over the past several days while we've been dry camping at The Grand Canyon, we've had to run the fridge off of LP gas.  This is a change from all the other places we've been - the fridge has run well on AC power.  However, after just a day, the fridge failed and we had to quickly either eat the food in the fridge or put it into our backup cooler we'd brought along just in case.

Here's where I got myself into trouble.  The panel to access the fridge guts is easily accessible on the outside of the RV.  There are some aluminum tubing LP lines connecting the main LP gas source to the burner.  Thinking that they were clogged or kinked (which they were) I started to disassemble the lines.  The aluminum was so old and corroded to the brass fittings that instead of coming apart cleanly, the parts folded, bent, and twisted off.  It was a complete mess, and in the end I wound up with a bunch of valves and a whole mess of broken LP lines.  To make matters even worse, based on some previous calls to customer support, I knew I could no longer easily get parts for the fridge, especially on the road.

 

Link to the annotated picture of these parts...

We stopped in Kingman, AZ on the way to Las Vegas and I purchased some parts and tools to try and rebuild the fridge LP system.  The goal was to recreate the aluminum tubing using copper tubing I'd found at Home Depot used for ice maker hookups.  It was a little tricky because the bends were aggressive, nearing the minimum bend diameter of the tubing used.  Additionally, the ends needed to be flared - to fit into a flare fitting.  I'd never done any of these operations, so I made sure I had extra tubing to play with.

Making new tubing parts

After a couple of trials, I was able to rebuild the necessary LP system tubing completely.  Using a toothbrush and some soapy water I checked for leaks and then fired it up. 

Checking for leaks

The size of the flame in the LP chamber seems to indicate that the fridge should work much better now!