Reply
 
Thread Tools Display Modes
Old 05-29-2014, 01:45 PM   #1
Junior Member
 
Join Date: Feb 2012
Posts: 16
Dometic Fridge OK on shore power, not OK on gas

When I'm running on 120V shore power the fridge is plenty cold. When running on LP the freezer is cold enough to freeze water but refrigerator isn't as cold as on AC. Burner is lit and flame looks OK. Any ideas or suggestions?
__________________

__________________
George359 is offline   Reply With Quote
Old 05-29-2014, 06:05 PM   #2
Senior Member
 
Join Date: Aug 2011
Location: Albany, GA.
Posts: 799
I have to ask this: Are you checking the fridge temp with your hand or a thermometer? My understanding is that an RV fridge works on "heat absorption" rather than creating cool circulating air as a home fridge does. IF there is nothing in the fridge then it may feel as if it is not cooling properly. I had somewhat this same problem with my units fridge after I bought this used unit. I leave my unit hooked up when it's in the back yard to allow the fridge to run on a low setting. My fridge didn't "feel" as if it were cold enough yet the freezer felt fine. When I mentioned this to a friend of mine who has had an RV for years he told me to put as many water bottles in the fridge as I could. Even filling old milk jugs with water would be good for it I was told. That worked! For some reason having the fridge cool the water bottles down made it seem to work better. And- -I have cold water bottles at hand when I'm working outside.
__________________

__________________
Thurman is offline   Reply With Quote
Old 05-29-2014, 06:17 PM   #3
Junior Member
 
Join Date: Feb 2012
Posts: 16
Thanks for the tips. My test for the temperature has been to hold and taste a beer that's been in there. Will try to put more inside, like you say, water bottles make sense. or a full case of beer, though those have a tendency to disappear
Also heard that increasing the airflow from the side vent to the roof vent can help so am looking into solar fans that are used to do that. Anyway, appreciate the response. Happy summer!
__________________
George359 is offline   Reply With Quote
Old 05-29-2014, 06:21 PM   #4
Site Team - Lou
 
Herk7769's Avatar
 
Join Date: Oct 2009
Location: South Eastern PA
Posts: 21,168
Normally, it is the other way around. The propane has a much higher and faster heat transfer to the boiler and thus cools much more quickly than the AC heater element.

For AC to be better means the flue might be blocked with something (perhaps a wasp/bug nest) limiting heat transfer due to wasted heat coming out the bottom instead of up the flue.
__________________

Lou and Laura with Bella - German Short Hair Pointer
2008 GMC Sierra 2500HD Crewcab SB Allison Duramax
2010 Flagstaff 8526RLWS - Superglide 3300
HAM CALLSIGN - KC3FFW
Herk7769 is offline   Reply With Quote
Old 05-29-2014, 06:27 PM   #5
Junior Member
 
Join Date: Feb 2012
Posts: 16
Yep, planning to look in there and clear out any obstruction. That's what I've heard though that the LP usually works better than the AC. Thanks.
__________________
George359 is offline   Reply With Quote
Old 05-29-2014, 08:14 PM   #6
Senior Member
 
Join Date: Oct 2013
Location: Georgetown, TX
Posts: 276
Can't happen - the method for cooling the freezer and frig is exactly the same regardless if on propane or electric.

What is happening is the thermister that controls the temp is on the fins at the top of the frig portion. By adding "stuff" you make the inside of the frig warmer signaling the frig to produce more "cold". It will do so until the temp reaches the preset level and it will stop cooling. The end result is the "stuff" in the frig cannot get any colder than the preset level whether you have got one or many "stuffs".
__________________
cadman99 is offline   Reply With Quote
Old 05-29-2014, 08:29 PM   #7
Junior Member
 
Join Date: Feb 2012
Posts: 16
OK, so something is triggering the thermister to think it's gotten cold enough. putting warm stuff near the thermister should trigger it to cool more...maybe. Another clue. thanks.
__________________
George359 is offline   Reply With Quote
Old 05-29-2014, 08:39 PM   #8
Senior Member
 
Join Date: Oct 2013
Location: Georgetown, TX
Posts: 276
I am sure you will see a 3-5 difference between when to turn on and when to turn off. However it is hard to believe that adding jugs of water make a huge difference. It only gets as cold as it gets. Disable the thermister and it will freeze everything in the frig.
__________________
cadman99 is offline   Reply With Quote
Old 05-29-2014, 08:45 PM   #9
Site Team - Lou
 
Herk7769's Avatar
 
Join Date: Oct 2009
Location: South Eastern PA
Posts: 21,168
Quote:
Originally Posted by cadman99 View Post
Can't happen - the method for cooling the freezer and frig is exactly the same regardless if on propane or electric.
With greatest respect, you are correct that the method for cooling is the same; Heat, from whichever source, "boils" the ammonia in the reservoir when cooling is needed.

Just saying, like heat from an electric range vs a gas range, the gas flame will get get the water in the pan to boiling quicker than the electric element on High. The water will not care as it boils at 212 degrees F; just it will reach it faster on gas.

In this case, if the available heat from the propane is being diverted (or corrupted - reduced - by a bad mixture), the AC heater might out perform the gas flame; which is normally not the case.

The "ON" time of the heat is dependent on the outside air temperature.
The hotter it is outside, the more often you will need to cycle the coolant.

The worse the efficiency of the heat source, the "warmer" the interior of the fridge will be for the same "fin" thermistor setting.

Obviously, if allowed to stabilize, the temperature inside will be identical. The wild card is the "weather" and the amount of cooling actually needed to maintain that temperature.

Hope that explains what I am trying to say, better.
__________________

Lou and Laura with Bella - German Short Hair Pointer
2008 GMC Sierra 2500HD Crewcab SB Allison Duramax
2010 Flagstaff 8526RLWS - Superglide 3300
HAM CALLSIGN - KC3FFW
Herk7769 is offline   Reply With Quote
Old 05-29-2014, 08:45 PM   #10
Junior Member
 
Join Date: Feb 2012
Posts: 16
Things seem to be pointing at that thermister and it makes sense, but why doesn't it act that way on AC? Will look at it when I get back to the rig and mess around there a bit too.
__________________

__________________
George359 is offline   Reply With Quote
Reply

Tags
dometic, fridge, gas, power

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off



» Virginia Campgrounds

Reviews provided by




ForestRiverForums.com is not in any way associated with Forest River, Inc. or its associated RV manufacturing divisions.


Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -5. The time now is 12:00 AM.