Fridge runs on propane but doesn’t cool

[DanHoug]

one other caution... that reamer is VERY fragile. the hair-thin tri-lobe hardened steel ream breaks off if you drop it. BTDT!
_________________
-dan
60% of what you find on the internet is wrong, including this post.

'87 Westy & '89 Westy both 2.1 4spd

Past projects can be found at--
www.thefixitworkshop.com

[jpbarnes]

[latelogan]

my understanding is the click is the 120VAC heater switch in the thermostat

I recall that the high flame came on right about where the click was. (I had mine out on a bench with a BBQ setup a couple of times)

I agree with others here that the thermostat gas side function is the root cause. You might just try moving it up and down rapidly many times, that might unstick it. You might also apply a bit of heat to it (NO FLAME: hot wet rag or a bit of boiling water) while you are moving the thermostat control up and down.

I have not seen anything on rebuilding these on the gas side, but I'm guessing it is possible. especially since the 120 is coming off and on.

(FWIW: 12VDC runs flat out, no thermostat control)
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1991 Westy stock 2.1 auto transmission
1978 Westy (Sold)
1971 Westy (Sold)

[strawman]

Hey guys
I’ve had to put the fridge issue on hold while I’m dealing with some other things with the van. Just wanted to let you know that I will definitely get back to everyone once I have this fixed.
I really like the idea of applying some heat to the thermostat dial first. I’ll try rapidly moving it as I use my hairdryer to heat it up. I’m considering buying a heat gun, do you think that would be too much heat?

I’m also thinking of swapping the thermostat controls of my two fridges. There is a coil of silver tubing that goes into the back of the fridge. I think this sends a signal to the thermostat to crank up the flame if it gets too warm in the fridge.

Can I simply remove the caulking holding it in place and pull it out? Or is this something that involves removing the fins inside of the fridge?
Thanks

[coastdog]

Hi Dan,

I won’t claim expertise on the inner workings of the thermostat but I have switched them out before with success and to the best of my knowledge that silver wire referred to in the linked manual as a capillary tube is a temp sensor for the thermostat. My best guess is that based on the set position of the thermostat dial and the capillary tube sensed temperature of the fridge, the thermostat will cycle between its only two settings, idle and full.

If you decide that you need to switch out your thermostat, the end of the capillary tube is tucked in a channel on the back of the ice tray fin assembly. As described in the linked manual on page 8, you have to pull the ice tray fin assembly away from the evaporator tube gently. It is held together with thermal mastic and should stick back in place after you have installed the capillary tube from your replacement thermostat.

I’ve never tried heat on the thermostat before but if you use a heat gun be very carful of any plastic parts nearby.

http://techsupport.pdxrvwholesale.com/wp-content/uploads/2019/01/Dometic-Service-Manual-RM182.pdf

Bill

[jocoman]

I'm in the same boat as well. The flame that I see in the little viewing hole does not get any brighter when I increase the thermostat.
I would think that even if the jet was not the perfect size (i.e. some buildup) you would still see a noticeable different in the flame as you increase the thermosta?.
I have a spare fridge for parts but is there any way I can actually test the thermostat?
The spare fridge works on propane as well and displays the same issue. So I am at a loss on moving forward. I really, really like the propane fridge, so I want to keep going with it.
_________________
'86 Westfalia 2.0L Zetec
'97 Volvo 850 AWD Turbo
" The fun never stops"

[coastdog]

This is the combustion flame on full. I don’t have picture at idle but it’s just a slightly smaller flame.

The only way I know to test the thermostat is to take the fridge out of the van and visibly watch the flame change as you rotate the thermostat. Before you remove the fridge you can also watch the camper panel LED change brightness slightly as you rotate the thermostat. This works best with the GoWesty LED camper panel installed as the blue fridge light is bright compared to the stock green LED.

Bill

[jpbarnes]

[jocoman]

Or is it possible to service an existing thermostat?
_________________
'86 Westfalia 2.0L Zetec
'97 Volvo 850 AWD Turbo
" The fun never stops"

[strawman]

Hi guys
Super excited to say the problem has been solved!

So I did all the things people recommended except for one thing which I’ll reveal later. I cleaned the fire box and the drain tube. I blew compressed air into the propane pipe while holding in the propane bypass valve. This was after it was disconnected from the firebox. I did all the recommended vacuuming of intake and exhaust. All of the above are great things to do, actually the vacuuming thing should be a yearly thing. My old 82 van fridge wouldn’t light up after sitting 2 years and after just vacuuming it sparked right up.

I took the jet out and soaked it for a couple of days in lacquer thinner then used compressed air to blow it out. No change. I then took the jet to our only jewellery store , I live in a small town, and asked if they could clean it in their ultrasonic cleaning machine. Wow after 1-1/2 hours I could see lots more light though the jet opening.

Problem solved, I can now hear the roar of the stage 2 setting and then shutting off in the idle mode. So thanks to DanHoug for putting that idea in my head. As well thanks to everyone else who contributed to this thread.

On a sidenote, when I bought this 1991 van I asked the seller if the fridge worked. He said no but oh well you know these fridges never work. After having fixed my 82 fridge I kind of just chuckled inside knowing that that was not necessarily true.

Cheers
Dan

[coastdog]

Great news Dan! Glad you got it working and that’s good information to take forward. Over the years of looking through these gas nozzles I’ve gotten used to looking through them after soaking and blowing them out and I’m used to the pattern I usually see. I haven’t run into a badly restricted one yet but based on your experience I’ll be ready for a trip to the jewelry store.

Do you have any idea what was causing the restriction… corrosion?

It’s amazing what you learn on here. I do have a slightly damaged thermostat that I plan to take apart and learn from. I’ll post info and pictures when I do. Earlier on this thread you mentioned the click that you heard on your thermostat. Latelogan mentioned above that the click is part of the thermostats 120v function and although I can’t verify that yet I suspect he is correct. So ‘I think’ in the 120v mode, the thermostat has linear control of fridge temperature like a house thermostat and the click is the variable cut out point determined by demanded temperature and sensed temperature. In gas mode as discussed here, there is just full flame and idle flame. What I don’t know yet is if that is a fixed point on the thermostat dial for that transition. I will find out on the next fridge and report back. And in 12v mode, there is no thermostat control and it’s just 84watts/12v=7amp draw.

Thanks for following through to you and others who helped solve your problem.

Bill

[jocoman]

Just piggy baking on this thread, because it has a great collection of wisdom.
My fridge does not get very cold as well. I cleaned the burner chamber etc. but still no joy. Here are pics of low flame and high flame. Do they look resonable?
Also the OP said he heard a roar when he put it to high. Mine is quite silent on high. Wouldn't know it was running unless you touch the exhaust. Thanks all!

_________________
'86 Westfalia 2.0L Zetec
'97 Volvo 850 AWD Turbo
" The fun never stops"

[jocoman]

I'm suprised nobody commented on my flame, however looking at one of the posts from above, I would say my flame is poor. It looks blue on the sides but nothing in the center of the burner. I wunder what could be the cause? The jet looked very clean. Comments? txs
_________________
'86 Westfalia 2.0L Zetec
'97 Volvo 850 AWD Turbo
" The fun never stops"

[coastdog]

Pictures are a bit dark to tell. Might need to check your gas regulators water column pressure, or thermostat function. If the flame looks small when the thermostat is full, something is restricting gas flow.

Dan above said that even though his jet nozzle looked good it needed ultra sonic cleaning and he got that done at a jeweler. Maybe…

Bill

[strawman]

Hey Jocoman
When I first started this process the exhaust and burner box got quite hot. I could touch both of them but not for too long. Having no experience of bench testing with propane I thought this was good enough.

So I removed the jet and soaked it for a couple of days in lacquer thinner. I could see light though it but having no reference point I assumed it was plenty good enough. Reinstalled it and no improvement.

Reading my previous post you’ll see what happened when I tested my spare fridge. Burnt my fingers touching the burner box after only 15 minutes of run time and super cold fridge after 45 minutes.

I was thinking of swapping jets but then remembered DanHoug suggesting I ultrasonically clean the jet. When that was done I could see twice as much light through it. When bench testing again the second stage flame had a wonderful deep rumble to it and the fridge cooled quickly.

I installed the fridge yesterday then went for a hour long drive. While I normally only drive with the fridge on 12v I was pleased to see that the flame never blew out while on propane. I took that to mean I’ve got a healthy flame going on.

I did buy the jet cleaning tool which I would have used if the cleaning hadn’t worked. Man it’s nice to have a great running fridge. Keep at it, you’ll figure it out.

[jocoman]

@strawman
Thanks for the words of encouragement. I'm getting kind of tapped out on this one. According to Frank Condellini maintenance procedure, I should be able to get the temp down to -7 C after one hour. The best i can do is 3.6 c after 2 hours. So I'm not where I need to be. Can you reach -7C in 1 hour?
Also the 24# on the jet refers to flow not orfice size according to chatgpt. I believe the orfice is just under .0135" or .343mm
I have a small ultrasonic cleaner 40 watts. I have run it thru several times with a vinegar solution.
I am trying again today with a simple green solution. I don't know if my cleaner is poweful enough. Apparently the E-string of a guitar should be close to the diameter and could be used as a reamer.
That's where I am at. txs
_________________
'86 Westfalia 2.0L Zetec
'97 Volvo 850 AWD Turbo
" The fun never stops"

[dobryan]

[Tobias Duncan]

The temperature of your fridge is dependent on the temp in the van. That fridge will only cool 40 degrees below whatever the ambient temp is at the moment.
This is a moving target I think right?

I mean the thermostat will shut down before things get too cold if you are camping in the shoulder seasons(I think) but it cant exceed the 40 degree f limitation.

I am right about these assumptions?

[jimf909]

[Ahwahnee]