Hello! Log in or Register   |  Help  |  Donate  |  Buy Shirts See all banner ads | Advertise on TheSamba.com  
TheSamba.com
 
Dometic question #94567
Page: 1, 2  Next
Forum Index -> Vanagon Share: Facebook Twitter
Reply to topic
Print View
Quick sort: Show newest posts on top | Show oldest posts on top View previous topic :: View next topic  
Author Message
Californio
Samba Member


Joined: May 17, 2007
Posts: 1280

Californio is offline 

PostPosted: Mon Mar 18, 2019 4:23 pm    Post subject: Dometic question #94567 Reply with quote

Ok. Given all the Dometic threads you'd think I could find the answer, but no.

My later-model 182B (auto-electric spark) is running on propane. The flue pipes are hot, and the led is on. But it isn't getting cold. I've tried different thermostat settings. Not cold. Nope.

I removed the fridge, aired out the flue, disassembled the combustion chamber, and aired that out. Cleaned the inside of the burner orifice using electric contact cleaner and compressed air.

The sparker works fine and the flame lights. But no cold.

It works perfectly on 12V. Cold.

This is impossible, right?
Back to top
View user's profile Send private message Gallery Classifieds Feedback
dlb154
Samba Member


Joined: December 27, 2006
Posts: 359
Location: Reno, NV
dlb154 is offline 

PostPosted: Mon Mar 18, 2019 4:40 pm    Post subject: Re: Dometic question #94567 Reply with quote

Possible if the refrigerant has leaked out of the system. It's a closed loop system changing from liquid to gas and back again. If it's leaked out (rusted tubing or puncher in the tubing) it won't work...
Back to top
View user's profile Send private message Gallery Classifieds Feedback
Californio
Samba Member


Joined: May 17, 2007
Posts: 1280

Californio is offline 

PostPosted: Mon Mar 18, 2019 4:50 pm    Post subject: Re: Dometic question #94567 Reply with quote

But if the refrigerant had leaked out, it wouldn't work on 12 vdc, right?
Back to top
View user's profile Send private message Gallery Classifieds Feedback
Ahwahnee
Samba Member


Joined: June 05, 2010
Posts: 9778
Location: Mt Lemmon, AZ
Ahwahnee is offline 

PostPosted: Mon Mar 18, 2019 5:00 pm    Post subject: Re: Dometic question #94567 Reply with quote

Are you running it om AC for a while (say overnight) before switching to propane?

The 110V setting gets a nice draft going in the flue that helps the gas do its work.
Back to top
View user's profile Send private message Gallery Classifieds Feedback
Yellow Rabbit
Samba Member


Joined: August 31, 2005
Posts: 1145

Yellow Rabbit is offline 

PostPosted: Mon Mar 18, 2019 5:12 pm    Post subject: Re: Dometic question #94567 Reply with quote

How long has it been running? It can take an hour or two to cool down.
Back to top
View user's profile Send private message Gallery Classifieds Feedback
Californio
Samba Member


Joined: May 17, 2007
Posts: 1280

Californio is offline 

PostPosted: Mon Mar 18, 2019 5:21 pm    Post subject: Re: Dometic question #94567 Reply with quote

It's been running a month or so. So warm inside I didn't even know the flame was lighted!
Back to top
View user's profile Send private message Gallery Classifieds Feedback
davevickery
Samba Member


Joined: July 16, 2005
Posts: 2887
Location: Fort Collins, CO
davevickery is offline 

PostPosted: Mon Mar 18, 2019 5:34 pm    Post subject: Re: Dometic question #94567 Reply with quote

That is a weird one. The clue is 12V or 110 works and LP doesn't. They all use the ammonia absorption cycling process to cool so that rules out a leak. You have to consider what it different in the 3 modes of operation.

In LP and 110 the thermostat dial is used. In 12 V it is ignored. So you probably should confirm it works on 110 to rule out something going on there.

The 110/12V heating element is shared but obviously the LP heating element is different. So could it be lit on LP but the pilot is too small? Are you able to observe the flame? Does it go up in size when you move the thermostat from its lowest setting to mid-way? You should be able to hear the thermostat click when you turn it. It just goes from pilot to full and back to pilot as you turn it down up down.

And do you have a wireless thermostat you can position under the fins to test it and give specific numbers? I would think you would get a little bit of cooling even it can only come on to pilot light setting.
Back to top
View user's profile Send private message Gallery Classifieds Feedback
DanHoug
Samba Member


Joined: December 05, 2016
Posts: 4720
Location: Bemidji, MN
DanHoug is offline 

PostPosted: Mon Mar 18, 2019 5:39 pm    Post subject: Re: Dometic question #94567 Reply with quote

okay, if it has been running a month or so, the flame is not raising above the pilot level. otherwise, you'd go 2 weeks max on a tank of propane.

you should be able to see the flame difference in the sight glass, and hear it with your ear to the flue vent, between the minimum pilot setting and the call for increased cooling when the temp knob is turned. if there is no difference, your control valve/thermostat system is haywire.

the fact that it works on 12v means your refrigerant system is working. further, the 12v system is not controlled by the temp knob. it's either on or off according to the rocker switch.
_________________
-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
Back to top
View user's profile Send private message Send e-mail Gallery Classifieds Feedback
Californio
Samba Member


Joined: May 17, 2007
Posts: 1280

Californio is offline 

PostPosted: Mon Mar 18, 2019 5:49 pm    Post subject: Re: Dometic question #94567 Reply with quote

I only have the LP and 12vdc options as I eliminated the AC long ago.

I can't see the flame through the sight glass, not sure why. The burner tube and all the rest look normal when I take them apart. I know for sure it's lighted as the flue is too hot to touch.

It seems to me that if the combustion chamber gets hot with propane, and the fridge cools on DC, then it ought to work.

Maybe the thermostat is the culprit. That seems like the only possibility.

I'm starting to wonder if it's worth a fix, though I do like the ancient, inefficient Dometics. They seem like the perfect fit for the Vanagon in so many ways.
Back to top
View user's profile Send private message Gallery Classifieds Feedback
Californio
Samba Member


Joined: May 17, 2007
Posts: 1280

Californio is offline 

PostPosted: Mon Mar 18, 2019 5:51 pm    Post subject: Re: Dometic question #94567 Reply with quote

Dan, I actually have two propane tanks installed...the Dometic usually runs at least six weeks without a refill.

Yes, I'm thinking it has to be the thermostat.
Back to top
View user's profile Send private message Gallery Classifieds Feedback
DanHoug
Samba Member


Joined: December 05, 2016
Posts: 4720
Location: Bemidji, MN
DanHoug is offline 

PostPosted: Mon Mar 18, 2019 5:55 pm    Post subject: Re: Dometic question #94567 Reply with quote

i have a similar soft spot for these irrascable Dometics (and would gladly take a throw away.. hint hint). i keep a day's worth of meat perishables and just don't rely on it for long term storage. doesn't matter if things warm up a touch if used within the same day (i'm a former Health Inspector). and it keeps my chocolate and butter from melting regardless of interior temps.

the ice cube tray affords a single cold gin&tonic at the end of the day. the rest are drank warm <grin>.
_________________
-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
Back to top
View user's profile Send private message Send e-mail Gallery Classifieds Feedback
DanHoug
Samba Member


Joined: December 05, 2016
Posts: 4720
Location: Bemidji, MN
DanHoug is offline 

PostPosted: Mon Mar 18, 2019 6:11 pm    Post subject: Re: Dometic question #94567 Reply with quote

there's 3 key elements to the sight glass....

- the glass window on the combustion chamber needs to be clean on both sides of the glass.

- the end of sight tube near the combustion chamber gets fogged over. simply polish it by furious rubbing on your thigh while wearing blue jeans will polish it clear and shiny.

- the alignment of the sight glass needs to be correct. the end near the chamber window is slanted and this slant must be in parallel with the angle of approach to the chamber window.

hint: the sight glass is a friction fit in thru the frig insulation and can be removed from while the frig is in place by grabbing it with a locking forceps. slight digging into the foam insulation may be necessary.
_________________
-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
Back to top
View user's profile Send private message Send e-mail Gallery Classifieds Feedback
davevickery
Samba Member


Joined: July 16, 2005
Posts: 2887
Location: Fort Collins, CO
davevickery is offline 

PostPosted: Mon Mar 18, 2019 6:11 pm    Post subject: Re: Dometic question #94567 Reply with quote

Californio wrote:
Dan, I actually have two propane tanks installed...the Dometic usually runs at least six weeks without a refill.

Yes, I'm thinking it has to be the thermostat.


What do you mean you eliminated the AC? There is a cord on the back of the fridge that normally plugs into the 110 outlet under the sink. You could just plug the fridge into an extension cord and test it on 110. That would help pinpoint or rule out the thermostat.

And if you figure out what is broken, I just parted out a fridge and probably have whatever you need.
Back to top
View user's profile Send private message Gallery Classifieds Feedback
Californio
Samba Member


Joined: May 17, 2007
Posts: 1280

Californio is offline 

PostPosted: Mon Mar 18, 2019 6:33 pm    Post subject: Re: Dometic question #94567 Reply with quote

I replaced the 110VAC wiring with an onboard battery charger that connects to the AC plug on the side of the van. In 15 years of camping, I'd never once been close enough to AC power to use it. I have an inverter for 110VAC anyway, connected to the wall outlet.

So, I just went out and bypassed the thermostat altogether and relit the fridge. Now, the wait.

I'll try cleaning the sight glass per instructions as well.

If jumping the two black wires on the thermostat doesn't do it, then?
Back to top
View user's profile Send private message Gallery Classifieds Feedback
Californio
Samba Member


Joined: May 17, 2007
Posts: 1280

Californio is offline 

PostPosted: Mon Mar 18, 2019 6:35 pm    Post subject: Re: Dometic question #94567 Reply with quote

Yes, correct, I didn't think of just running the fridge off an extension cord.
Back to top
View user's profile Send private message Gallery Classifieds Feedback
spitsnrovers
Samba Member


Joined: December 17, 2005
Posts: 924
Location: Calgary, Canada
spitsnrovers is offline 

PostPosted: Mon Mar 18, 2019 6:51 pm    Post subject: Re: Dometic question #94567 Reply with quote

I'm confused by your description of the 2 black wires on the thermostat.

This diagram from a 1988 model shows a black and a brown, and it only controls the 110V heater element.
Image may have been reduced in size. Click image to view fullscreen.


As stated earlier, the 12V is not controlled by a thermostat. And I believe the propane valve is not a thermostat at all. It simply opens more or closes more between the low and high setting.

Does that help in your troubleshooting?

NOTE however, the switch, labelled SWITCH is as shown on the Dometic label. It is incorrect. That switch layout would never work! It is correctly a double pole, double throw switch, where the centre terminals are both either connected to the top terminals, or to the bottom terminals.
_________________
'88 VW Westfalia
'75 Triumph Spitfire 1500
Back to top
View user's profile Send private message Visit poster's website Gallery Classifieds Feedback
Ahwahnee
Samba Member


Joined: June 05, 2010
Posts: 9778
Location: Mt Lemmon, AZ
Ahwahnee is offline 

PostPosted: Mon Mar 18, 2019 7:04 pm    Post subject: Re: Dometic question #94567 Reply with quote

One other thing to consider is (if you have not recently done so) removing and cleaning the jet. The orifice can get really small with use and that will inhibit cooling a lot.
Back to top
View user's profile Send private message Gallery Classifieds Feedback
DanHoug
Samba Member


Joined: December 05, 2016
Posts: 4720
Location: Bemidji, MN
DanHoug is offline 

PostPosted: Mon Mar 18, 2019 7:04 pm    Post subject: Re: Dometic question #94567 Reply with quote

spitsnrovers wrote:

As stated earlier, the 12V is not controlled by a thermostat. And I believe the propane valve is not a thermostat at all. It simply opens more or closes more between the low and high setting.


on my '87 frig, i observe a single flame small/large change between pilot level and the call for cooling. it is not proportional. further, this call for cooling set point varies according to frig temp. so that suggests to me, at least on my 87 frig, the thermostat is regulating a high/low flame level dependent upon interior temp.
_________________
-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
Back to top
View user's profile Send private message Send e-mail Gallery Classifieds Feedback
Californio
Samba Member


Joined: May 17, 2007
Posts: 1280

Californio is offline 

PostPosted: Mon Mar 18, 2019 7:13 pm    Post subject: Re: Dometic question #94567 Reply with quote

The thermostat I was referring to is controlled by a knob on the front panel. My Dometic is from a 1990 or 91, maybe there's a difference in circuitry? On the back, a green wire on top of the thermostat goes to ground, and two black wires go to into the device itself. I jumped the two black wires.

Bentley 97.33c doesn't show this thermostat either.

No difference with the two wires connected...still not cooling though the flame is on...
Back to top
View user's profile Send private message Gallery Classifieds Feedback
Californio
Samba Member


Joined: May 17, 2007
Posts: 1280

Californio is offline 

PostPosted: Mon Mar 18, 2019 7:17 pm    Post subject: Re: Dometic question #94567 Reply with quote

I cleaned the jet with solvent by spraying it in where the propane connects and then blowing it out with compressed air. Three times. I didn't take the burner assembly out of the box, however.

I seem to remember something about gauze? Anybody know what that is?
Back to top
View user's profile Send private message Gallery Classifieds Feedback
Display posts from previous:   
Reply to topic    Forum Index -> Vanagon All times are Mountain Standard Time/Pacific Daylight Savings Time
Page: 1, 2  Next
Page 1 of 2

 
Jump to:  
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum

About | Help! | Advertise | Donate | Premium Membership | Privacy/Terms of Use | Contact Us | Site Map
Copyright © 1996-2023, Everett Barnes. All Rights Reserved.
Not affiliated with or sponsored by Volkswagen of America | Forum powered by phpBB
Links to eBay or other vendor sites may be affiliate links where the site receives compensation.