Vanagon Fridge Syndrome -- won't run on LP


Capt. Mike

Moderator
No, there are no electric solenoid valves in the LP system. The 'push to start' button opens air to the pilot light. That your's shuts off indicates it is not getting it's operating air supply, no doubt a flue problem. Remember, this is a two-way flue supplying air and exhausting heat at the same time. See the flue bulletin posted on the Tech Drawings link. It may look good but have lost it's seal or have an out-of-sight blockage that the 'push-to-start' is just bypassing.
 

cpgill

New member
I've owned my 1990 Westy for three years now and have always done all the above mentioned proceedures to get the fridge to run on LP. Two week ago before our first camping trip of the season I prepared to start the check list by running the fridge on AC overnight in order to preheat the flue. Just for the heck of it when I opened the door to push the plug button I decided to see if it would miraculously start on LP. I pumped the air three times and it started first try? I ran it overnight on LP, drove two hours to the campground on DC, and it started first try again on LP.

Last weekend the fridge started first try everytime again! I have done nothing in the way of maintainance over the winter. The first time I started it I could smell a strange burning odor that lasted about 15 minutes and went away. It conerned me enought that I monitored things to make sure nothing behind the cabinet was on fire.

So now I have a dometic fridge that starts first time everytime. Eat your hearts out people. Unfortunatly my water pump stopped working over the winter and I have to troubleshoot that one.
 

guest

New member
Capt. M., are you sure that button opens air to the pilot light? I'm pretty sure it permits propane to travel to it, instead of air. Or perhaps it's a combination of propane and air.

If you look at the layout of the propane lines on the top of the fridge, the start button seems to actuate a gate valve for the propane intake to the combustion chamber on the bottom. I believe the Dometic service manual called this thing a "safety button" or some such - it's not handy to me right now. I'm pretty sure that no propane flows to the combustion chamber unless that button is pressed (my "nose" and "match" tests seem to confirm this assumption, after first removing the spark plug from the side of the chamber). I think air is provided to the combustion chamber by the "pump" dial & ignitor button - ie. the far left control. The start button that I'm talking about is the button to the right of that thing.

This is why I am puzzled that there is any possibility of continued flame burning at all once the start button is released - how would that gate valve on the top of the fridge continue to permit propane to flow when the button is released, if it wasn't through the use of an electric solinoid?

Can someone set me straight here?
 

lono

New member
I think the flame drives a thermocouple which generates a voltage that drives a solnoid gas switch. This keeps the propane flowing. In this way the gas will shut off if the flame goes out.

Lono
 

Capt. Mike

Moderator
guest: I think you're right. Too many reference materials and not doing my homework. The Dometic manual calls it a control button with little discussion of it's role, despite a very good diagram and description of the air-pump & piezo-electric starter. The control buttom is mentioned about 3 paragraphs down almost as an afterthought with little description of its role. I presumed (wrongly) it contolled the flow from the air pump since the Dometic manual had in that sequence.

The factory camper manual calls it a safety button. Seems an odd description since it's normal position is 'off' but I suppose manual control of the gas with an automtic shutoff when the button is released could be considered a safety button.

Glad someone is checking up on me. I sometimes get a frustrated and then careless after an hour of cleaning up new posts that are identical to what's already posted if the member would only look at an index. Thanks again.
 

icarus

Moderator
While I have never had to take my fridge out of my syncro so I can not say for sure if the following is true; My other dometic fridges all have a thermocouple in the burner flame. Holding the button overrides the thermocouple, which is why it lights but goes out when you take your hand off. The thermo couples have a very long life. ( I have one that is been in the flame of a dometic continiously for 15 years) They are cheap and easy to replace, once yo remove the fridge!)

Good luck,

Icarus
 

terrydarc

New member
Just a nice thanks to all here and especially Capt. Mike for the invaluable help in getting my '88 Westy Dometic to light up on gas - finally! We just bot our rig a month ago and took it camping, naively figuring to light the fridge when we got to the campsight. No way! Read this thread and did the prep work (blow thru the drain plug, remove and clean the flue, run fridge on 120v for a couple days, fire up the stove for a couple minutes...). The latter was nice cuz it made the camper nice and warm inside, too.

Went thru the motions of pumping, priming, sparking, pumping, priming... and would not have known the darned pilot light was on except I turned the panel status light on figuring it couldn't hurt and there was the blessed green light. Lying on the floor and trying to see the pilot light is a joke in the daytime! Spose feeling the flue after a while would also have worked but that status light sure made me feel good. Thanks all!
=Terry
 

Trout_Teaser

New member
My insight on the Westy fridge. My 1984 system is as stuburn as most when it comes to lighting on the l/p setting. I am not really talking about the system getting cold just getting the pilot light lit and staying on. Assuming that everything else is working correctly here is what I have observed and do.
First part is all settings need to be correctly set.

Observations:
The area around where the pilot light lives seems to be a poorly ventilated area and possibly very small in capacity. Because of this it is possible to have too much l/p present and lighting the pilot will be nearly impossible (too rich). On occasion I have seen and heard a much larger flame then should be present for a good ignition of the pilot light. Sometimes this little explosion will occur a few minutes after I have stopped pressing and holding the button in for the propane. I will have continued to pump the air pump and engage the ignitor. At some point I will light the fuel that remains in the chamber and will have a good flame up. I suspect the pumping has served to lean out the mixture until an igniteable air/fuel ratio was established to burn off the remaining gasses. The other way I have seen this happen is when the pilot light is lit and running. When I lift off of the button for the l/p the flame will continue to burn a few seconds then weaken and die. The thermocoupler still has some residual heat from the flame and will continue to flow l/p for a period of time after the flame has gone out. When this happens a "rich" environment is created. Keep pumping air and every once and a while engage the ignitor. At some point you might observe the mini explosion. During this period do not depress the l/p button as that will only add more l/p into the system and you want less.


Important: Depressing down the l/p button for long periods of time will only "flood" the chamber and make it harder to start on l/p. The button is an override for the thermocoupler and will continue to release gas as long as it is depressed. L/p gas is heavyer then air and will force oxygen up the intake pipe flue. If this happens it takes a lot of pump strokes to clear things out.
To get things started I will pump the air pump several times to get oxygen into the system. Then depress the l/p button for just a few seconds (no more then 5) before using the ignitor. Most often it lights on the first depression.

Sometimes even with the flame burning and the button depressed the flame will weaken and die. I suspect that this is due to not enough oxygen coming in. The system needs a good amount of heat to create a strong enough updraft to pull in more oxygen. While still continuing to hold the button in I will as needed continue to pump the air pump. In the sight glass I will see a much improved flame and the monitor panel l.e.d will glow brighter.

At some point I will release the l/p button and watch the flame thru the sight glass. If I see the flame weaken immediatley I depress the l/p button again and give a few pumps with the air pump. Heat must soak into the thermocoupler. If the thermocoupler is not hot the fuel will shut off right as the button is being released. Once the thermocoupler is hot I can release the button and the flame will stay lit, sometimes this might last for only 10 seconds and then the flame will get small and weak. No updraft and the oxygen is being burned off. If I observe this I will pump the air pump several more times quickly. As I do this the flame will dramaticaly improve in strength. After a few minutes enough heat, updraft, will be created by the pilot light that it will be able to sustain itself.

While going along this learing curve I have had it so "rich" that the ignitor would not even spark. I would have to pump almost 50 times maybe more to get things "cleared" out. Every 10 pumps I would engage the ignitor. No depressing of the l/p button. Typically at some point I would get the mini explosion. When that occured then I knew I was ready to try and light the pilot light with the l/p button held in.

Having done this a few times I have learned a few tricks.
Even if it has been sitting for months unused I can get it to light first time and almost always stay lit.
I pump the air pump several times. Then hold l/p button down for just a brief period time before depressing the air pump to the ignition position. If it does not light on the first click I click it several more times. I then observe the flame and pump the air pump as needed to maintain a strong flame. After about 30 to 45 seconds I release the l/p button and continue to observe the flame in the sight glass. If the flame weakens I give several more pump strokes till it looks strong again. After about 3 minutes maybe less the flame stays steady and I no longer need to watch it.

If the system has been running on 12v or 110v it seems to stay lit much easier and I think that is due to the heat rising and generating the needed up draft to pull in more oxygen for the flame to burn on l/p.

Hope that helps :

I am only guessing as to how things work in regards to the flue and pilot light on the backside of the fridge as I have never had to pull mine out.
 

Capt. Mike

Moderator
Transferred to consolidate same topic.

matthew greenleaf Junior Member posted May 22, 2005 05:21 AM

I have a 84 Westie and my original fridge runs strong while we are plugged in but I get nothing when I try to run it off propane. My stove runs great off the propane. I am confused and any help would be grateful.

zookz Power Member posted May 22, 2005 06:01 AM

Have you read through all the posts in the:
"Vanagon Fridge Syndrome --- Fridge won't run on LP" thread?
http://westfalia.org/eve/forums/a/tpc/f/64160255/m/9256040411

matthew greenleaf Junior Member posted May 22, 2005 07:59 PM

The 20 step process posted by Capt. Mike under working on the fridge worked. I followed each and every step and within 5 minutes after placing the fridge back in her home the pilot light worked. I am absolutly thrilled.


Thank you so much.

zookz Power Member posted May 23, 2005 04:21 PM

Wooohoooo!

A. Cooper Super Member posted May 23, 2005 05:12 PM

... and yet another Westy fridge is restored to functionality, and saved from the scrap-metal crusher. Congratulations!

To get the most from your fridge, and to keep it working for years to come, be sure and browse thru the numerous other posts under the FRIDGE section. Of special note is the necessity to run the fridge nearly level; that is, tilted no more than +/- 8 degrees in any direction, according to the VW Owner's Manual (although other industry experts suggest 4 degrees). I suspect failure to follow this simple rule is the cause of many inoperative Westy fridges.

If you are not inclined (no pun intended) to purchase store-bought RV levelers, Capt. Mike offers his instructions for making your own here:
http://westfalia.org/eve/forums/a/tpc/f/87160555/m/2496022211

Congratulations again, and when you open that first cold beverage in your campsite, remember to raise a toast to Westfalia.org!

Jeffrey "Cooper" Earl
1983 diesel Westfalia "Vanasazi"
http://www.vanthology.com/
 

jerepowers

New member
Thanks to both Trout Teaser and Capt. Mike for help with the refrigerator.

I finally got around to installing the check valve upgrade on my 1984 Westy. After reading Trout Teasers post, I had a better understanding of how the pilot light ignites and what its prolems are. By understansding that the chamber becomes flooded, I now stop pressing the pilot override button while I pump air. Basically I pump air, when I'm about five seconds from being ready to press the igniter, I press the overrride button. Got it lit for the first time in three years and it took about five minutes of experimentation. I did get a couple of mini explosions. As recommended, I had beeen powering with 120-volt to heat up the chamber.

Also, as usual, the Bentley is confusing as to upgrade the check valve. I bought the kit from Go Westy. Go Westy provides the same instructions as the Bentley. It was confusing as to where to put the 'O' ring. I finally put it in between the two large steel washers, in a sense in line with the main rubber plunger. I assumed it's main purpose was to prevent air from running along the shaft. I also used some Nikon Nikonos 'O' ring grease to help seal things up. My original one-way check valve was a small steel one that is fitted to the end of a rigid pipe that runs down to the combustion chamber. As it also served as the thing to attach the hose from the pump, I removed it, discarded the tiny steel and rubber valve and drilled it out with the same 9/64 drill bit as is recommended during the retrofit of the new check valve. I sealed all hose connections with adhesive caulk, the newest Handyman's Secret Weapon.
 

tklos

New member
I have an interesting one. I had may problems lighting my fridge. After cleaning the flu with a vaccum cleaner, it started the first time and ran for 12 hours. Then it stopped. It lights the first time and goes on but it stops after 1/2 hour. The other unusaul thing is that the green pilot indicator never turns on. However, when I flip the switch to 12VDC, the green pilot light is always on???
 

Trout_Teaser

New member
I think I've read some posts about the pilot light going out after running for a while and it may have had to do with filling the tank correctly and purging (sp?) the tank of air. If you look around on the board you might find that in some of those older posts. Just use the search. Without running out to my Westy and checking I seem to recall that it is normal for the bottom indicator light to be on when the system is running 12vdc with the ignition key in the on van running position. No light when the key is in the off position.
 

tklos

New member
Thanks for the reply. My fridge is getting better everday. This time it ran for 18 hours and then shut off. There is still propane in the tank since the burners work. At this time I noticed that the second battery was dead because the over the counter light was dead as well the display LEDs above the fridge. I read in the propane section here that the fridge cycles to 12v sometimes. My question - Does the fridge need any 12v when operating?
 

Capt. Mike

Moderator
What year, model? Mods? Guideline #3!

The LP phase requires 12v DC to run the cooling fan. Failure would probably trip the overheating safety. The LP fridges in Vanagons do NOT automatically switch to 12v if the LP fails. See your owners manual on how switch-over is completed. Since the 2nd battery is not OE for most N. Amercian Vanagons, yours has probably been modified. Most 2nd battery installations do NOT switch the factory counter light to the 2nd battery -- it's too complex to be worth while.
 

tklos

New member
Thanks for your help and all the valuable posts here. I am getting good progress on my fridge now. At the beginning it was not lighting. I read a lot of posts here which did the trick. The problem with mine was probably that it was not used for a long time. It is important to clean the flute and the intake pipes with a vacum cleaner (put a cheese cloth to see how much junk you actually got rid of. My fridge lights quickly now but the LED on the front panel does not work or sometimes it is very weak. My indication of the fridge working is the pilot light but as you know it is hard to see in daylight.
90 Vanagon
 

glhoman

New member
The posts on this thread have been very helpful and educational, but I still have a problem with my 83 Westy fridge staying lit. I've owned this van for 13 years now and have only had this problem for the last year or so. I don't have any problem getting it to light initially, but it is very inconsistent when it comes to staying lit. I removed the fridge, cleaned the exhaust, intake, and burner area, made sure there is a good seal around the vent. I am wondering if it might be the thermocouple? If it is defective could it incorrectly sense that there is no flame and shut off the gas supply? If so, could this be intermittent so as to allow the flame to burn for 15 minutes one time and 2 hours another time before shutting off? By the way, the electric (120/12v) modes work fine. Any insights are greatly appreciated.
 

icarus

Moderator
Sounds like a tired thermocouple. It is cheap to buy but a pain to pull the fridge to change. The other thing to look for is to see if it is properly in the flame.

Good luck
 

Trout_Teaser

New member
I am seconding the thermocoupler. Funky little beasts. They are great when they work but they do get tired. If pulling things out to check if the thermocoupler is in the flame might as well replace it. I hear they are cheap.
 

howzbayou

New member
I've had the same problem with the pilot light under two different circumstances...One, when the van wasn't level...and two, at higher elevations when the air is thinner...are those ruled out?
 

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