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Thursday, July 26, 2012

Keep Your Fridge Cooler And More Efficient - Clean The Burner!

Refrigerator Hatch
    Lately, I have been trying to get the best efficiency I can from my RV fridge. I've added a supplemental fan, checked all the seals, fixed the chimney baffle and added a remote temperature display. I really should have started with simple cleaning! It's not hard to do, and can pay off quite nicely. I've also made removable thermal insulation to fit all my windows. I probably should have started with basic cleaning and maintenance, but hind sight is always 20-20!

Most RV refrigerators are either "2 Way," meaning they run on Propane or 110V AC Electric (Generator or Shore power supplied) or "3 Way" which ads 12V DC to the mix. Yes, I know there are other definitions of 3-way, get you minds out of the gutter!

Behind The Lower Vent Door
Begin by shutting off the power to the refrigerator! Then locate and open your lower outside refrigerator vent. These usually have a simple twist latch and hinge at the top. If you're lucky, you can get it to stay in the up position without dropping every 30 seconds onto your head while working on the fridge. Mine, well... didn't. Once open, you'll see a bunch of wiring for the fridge (and maybe other things) the lower half of the refrigerators cooling system and a cover plate over the propane burner assembly. This is usually held in place with 2 or more Philips head screws. Next thing to do is remove the screws and gently lift up and slide out the cover.

Chimney, Wiring with Burner Cover In Place 
Underneath, is the base of the burner chimney, wiring for the thermistor that senses whether the flame is on or off, the gas line(s) and finally the burner itself.  These will likely be covered by a sheet metal "box" that protects the components. Mine simply pulled straight out. Remove it and put it aside.
 ***NOTE: Remember how it came out!***
If you have a self igniting model, you will also see the spark (piezo) igniter and its' wiring. Now is a good time to take a close look at the wiring and make sure it isn't frayed or melted or even hanging loose after coming apart at the connectors! Repair whatever is broken.

Burner, Igniter And Sensor Assembly
Take a close look at the end of the burner itself. It will be a rounded cylinder with several "gaps" running across it at the end. This is where the propane gas burns to create the heat that will ultimately cool your fridge. Sitting on top of this, in the path of the flame, is the thin stiff wire that heats up and tells the control board there is a flame present. If this isn't working, it can easily shut down your fridge for safety's sake. The refrigerator will still work on electric, so you may be able to keep your provisions cold. Next, blow out any dirt or debris from in and around the burner with low pressure compressed air. Too high a pressure could damage it! I applied a can of compressed air like the photographers use.. Then blow out the junk hiding in the chimney above the burner. You may find a few 8 legged critters have moved in, especially if you have had a propane leak. For some reason spiders LOVE the smell of propane. Not me...I mean it is DESIGNED to smell bad, so you know it's around. Without the special additive it would be odorless. Imagine trying to figure out you had an accidental leak. I shudder to think how bad that could be. But it isn't. Propane smells BAD! It will let you know it's around.

Proper Flame Operation
Once the system is clean, move everything out of the way of the burner and chimney and set the refrigerator control panel to LP or Gas mode. Mine only has AUTO and LP so I switched it to LP. You should hear the flame come on. If it doesn't start and you are SURE you have electric ignition, the refrigerator control system will try to light it a couple of additional times. If you still have no luck, check the obvious things first. Do you have propane in the tank? Is the main or tank gas valve actually on? Once you get it lit, go back outside and look at the flame coming out of the burner. Does it have a deep blue color? Does it have a distinct shape coming out of the gaps in the burner? Almost like "fingers?" The red/yellow hot spots are where the sensors intersect with the flame and glow red hot. This is normal and needed for proper operation. When you are satisfied that everything is working properly, go and turn off the refrigerator. Come back out and confirm the flame is out.

LET IT COOL OFF!!!

Slide the cover back on the burner assembly and then screw the cover plate back over everything. You're good to go. You may not have fixed anything. In fact, it all could have been perfect to begin with, but it's a good idea to check this at least once a year. Especially if you winterize and store your RV for the cold months.

Be Seeing You...Down The Road,

Rich "The Wanderman"
www.thewanderman.com



6 comments:

  1. Dometic 3-way caravan refrigerator will not cool on gas. Burner is on but will not respond to thermostat settings, what should i do?

    ReplyDelete
    Replies
    1. Hmmmm....most likely the control board (or the "eyebrow board" could be fried. If you search online there are various testing procedures you can follow to locate the issue.

      If it cools on 120V AC than you know the cooling system is still functional and the problem is electronic in nature.

      Also, check for a clogged chimney....you never know.

      Rich "The Wanderman"

      Delete
  2. I bought one of those battery operated fans you sit in the bottom of the frig. Not sure if it is a joke or not. Is it better to install a fan that sucks up in the vent?

    ReplyDelete
    Replies
    1. Anon,
      I have a fan in my chimney. Look at the other articles on Fridge cooling I've written. The fan inside the fridge is for keeping the temperature more uniform inside.

      The chimney fan is designed to increase the overall efficiency of the cooling system.

      Rich "The Wanderman"

      Delete
  3. I cut a piece of window screen to place behind the outside cover to keep all the bugs mud dovers etc out .I cut a small hole so the lock fits thru and trimmed it to fit just with the door . Works like a charm.

    ReplyDelete
    Replies
    1. Anon,
      Great idea! That's next weeks small project.

      Rich "The Wanderman"

      Delete

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