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Foretravel Motorhome Forums => Foretravel Tech Talk => Topic started by: Jon H on May 21, 2012, 10:44:49 pm

Title: Dometic RM 7130 refridgerator won't cool below 41 degrees
Post by: Jon H on May 21, 2012, 10:44:49 pm
Having a new problem with my 1995 Dometic RM 7130 double door refridgerator / freezer.  Freezer & internal icemaker are working fine but can't get refridgerator temps below 41 degrees.  Have tried all 5 positions on the thermostat control, checked shelf loading for air circulation, and tried adjusting the "slider" without success. Have never had this problem before. Just had a level 1 and roof paint done at Xtreme.  Will get out the ladder in the morning to see if there's a new roof vent installed.  Can't find anything else in the original Dometic manual - will try Dometic's site tomorrow. Any other suggestions appreciated as usual.
Title: Re: Dometic RM 7130 refridgerator won't cool below 41 degrees
Post by: John Haygarth on May 22, 2012, 02:20:25 am
Had the same problem a few months ago on my side by side fridge Dometic and it finished up being the cooling unit. Decided to heck with it and got the whirlpool from Lowes in Nac' and installed that. Now all is fine. It cost 1/3rd the repair cost and we finished up with a nice pantry on the side (to use the left over space). Lost a bit of fridge cabinet space but what the heck.
John h
Title: Re: Dometic RM 7130 refridgerator won't cool below 41 degrees
Post by: Kent Speers on May 22, 2012, 10:33:39 am
Jon, it was great seeing you last week in NAC. Hope you and Linda have a safe trip to your new home in Florida.

Actually, 41 degrees in the 90 degree heat doesn't sound too bad. Where did you have the thermometer?

If that's just not cool enough, I had some issues last summer primarily due to the very high temperatures in Oklahoma. I added two RV Fridge Fans, Amazon.com: Valterra A10-2618VP FridgeCool 12 Volt Exhaust Fan: Automotive (http://www.amazon.com/Valterra-A10-2618VP-FridgeCool-Volt-Exhaust/dp/B002N5YDG2/ref=sr_1_7?ie=UTF8&qid=1337697342&sr=8-7), and dropped the inside temps to the appropriate levels. I installed mine using a toggle switch to manually turn them off and on rather than the thermostatic switch that came with the kit. You have to remove the roof vent and install them/it right on top of the coil. One fan probably would be enough but if one is good, two is better. Installation takes about two hours total.

You can find these fans at some RV stores but not at Camping World. There is also a kit with a solar panel to power the fan for about $59.
Title: Re: Dometic RM 7130 refridgerator won't cool below 41 degrees
Post by: Dan Stansel on May 22, 2012, 10:58:33 am
I just got a fan off ebay.  Hooked it up but have not had it on the road yet.  "Dometic/Norcold refrigerator Fan for RV 12 volt"  $15.40 plus $2.60 Shipping item # 250905640959.  Blows air into fins in back of unit at top.  Hooks right into the light switch/ constant hot.  I tried the small battery fans and they seem to help.  The problem with these units is the recovery time when the door is opened.  I keep a "Chaney" temp on the front of the unit so I can read the temp at all times with the door closed in the freezer and refrig. I am learning only to travel with fresh product and a small amount.  Luckily have an outside refrigerator /freezer in the bay.  Dan. 
Title: Re: Dometic RM 7130 refridgerator won't cool below 41 degrees
Post by: Jon H on May 22, 2012, 10:13:52 pm
Thanks to all for the suggestions. Tried running the unit on propane and refer temp dropped to 37 degrees.  switched back to electric and refer temp went back to 41.  Had a full bag of ice in one of the freezer shelves and removed that to see if air circ in the freezer was affecting the refer temp. After removal refer temp dropped to 37 on electric. Can't tell you why but happy with the results. ;D
Title: Re: Dometic RM 7130 refridgerator won't cool below 41 degrees
Post by: Patricia on May 23, 2012, 12:36:49 am
I just got a fan off ebay.  Hooked it up but have not had it on the road yet.  "Dometic/Norcold refrigerator Fan for RV 12 volt"  $15.40 plus $2.60 Shipping item # 250905640959.  Blows air into fins in back of unit at top.  Hooks right into the light switch/ constant hot.  I tried the small battery fans and they seem to help.  The problem with these units is the recovery time when the door is opened.  I keep a "Chaney" temp on the front of the unit so I can read the temp at all times with the door closed in the freezer and refrig. I am learning only to travel with fresh product and a small amount.  Luckily have an outside refrigerator /freezer in the bay.
Dan, last year we also bought one of the RV refrigerator fans on eBay (DOMETIC NORCOLD REFRIGERATOR FAN FOR RV 12 VOLT | eBay (http://www.ebay.com/itm/DOMETIC-NORCOLD-REFRIGERATOR-FAN-RV-12-VOLT-/250905640959?hash=item3a6b243fff&item=250905640959&pt=Motors_RV_Trailer_Camper_Parts_Accessories&vxp=mtr#ht_8624wt_1139)) and while it does work as advertised, it is quite "localized" - ie, frost would begin to form on fins not directly receiving benefits of blowing air - so I bought a second unit.  Both units together (alligator clips attached to the fins) still left a gap in coverage, so I would move the fans every day to insure coverage.  The other problem was noise - due to the fact that they are clipped to the fins, they rattle somewhat and could be heard during a quiet night.  So, before we left on our trip this month, I purchased a third fan - and George attached them to an aluminum strip (see photo below).  Since they hang in front of the fins, there is no noise - and since they are contiguous, they provide complete coverage - no frost build-up since we left!  (Peter, I know you mentioned you also use three fans - but riveted them together rather than attached to a strip to hang in front of the fins.  And, of course, there is Steve's elegant solution:  Refrigerator Fans Modification (http://www.beamalarm.com/Documents/refrigerator_fans_modification%20.html))

We also use the Chaney remote (wireless) thermometers to monitor temps in both the fridge and the freezer without opening the doors.  This product works great - I posted about it last year:  Refrigerator not Cooling ??? (http://www.foreforums.com/index.php?topic=12953.msg69694#msg69694)

You may want to order a couple more fans for complete coverage.  Also, you should not have to travel with a small amount in the fridge and freezer - they are much more efficient when filled with cold/frozen food.  Good luck!
Title: Re: Dometic RM 7130 refridgerator won't cool below 41 degrees
Post by: TheBrays on May 23, 2012, 07:33:58 am
Thanks to all for the suggestions. Tried running the unit on propane and refer temp dropped to 37 degrees.  switched back to electric and refer temp went back to 41.  Had a full bag of ice in one of the freezer shelves and removed that to see if air circ in the freezer was affecting the refer temp. After removal refer temp dropped to 37 on electric. Can't tell you why but happy with the results. ;D
Last year we had similar problems with our 7130. FOT determined that one of the electric heating elements was bad and the other marginal. Replaced both electrical elements and replaced the propane 'nozzle' (not the right word but you get the picture).
Has worked fine.

HTH
Title: Re: Dometic RM 7130 refridgerator won't cool below 41 degrees
Post by: Steve & Kathy B on May 23, 2012, 02:15:37 pm
Oh man!  I just put one of those single fans in my reefer fins, but only bought one.  Haven't tried it out yet.  May have to get some more!  Great mod regarding the fans on top too!
Title: Re: Dometic RM 7130 refridgerator won't cool below 41 degrees
Post by: Kent Speers on May 23, 2012, 03:26:34 pm
Oh man!  I just put one of those single fans in my reefer fins, but only bought one.  Haven't tried it out yet.  May have to get some more!  Great mod regarding the fans on top too!

I'm sure more is better but we have been getting along with one for over a year. Once in a while the get frost buildup but not very often and when we do get it it dissipates on its own.
Title: Re: Dometic RM 7130 refridgerator won't cool below 41 degrees
Post by: Peter & Beth on May 23, 2012, 04:17:58 pm
Ya...I started with one, then bought another two and used a piece of aluminum to rivet all three together.  I'll try this setup this week and report back.
Peter
Title: Re: Dometic RM 7130 refridgerator won't cool below 41 degrees
Post by: Patricia on May 23, 2012, 04:19:47 pm
I'm sure more is better but we have been getting along with one for over a year. Once in a while the get frost buildup but not very often and when we do get it it dissipates on its own.
Not better... just easier and quieter.

The "quieter" part is two-fold... no rattling/vibrating from time to time - not always continuous, but I simply could not clip it to the fins in just the right spot so it wouldn't vibrate.  The other part of "quieter" was for George - his mod meant I wouldn't whine anymore!  :))
Title: Re: Dometic RM 7130 refridgerator won't cool below 41 degrees
Post by: John Haygarth on May 23, 2012, 04:35:37 pm
Peter, I thought you had put in the whirlpool residential elec' fridge but obviously not, hmmm ::) who am I thinking about?
John H
Title: Re: Dometic RM 7130 refridgerator won't cool below 41 degrees
Post by: Peter & Beth on May 23, 2012, 04:56:39 pm
I think that Barry Leavitt (Barry & Cindy) installed the first whirlpool residential fridge in the Foreforums.  Then others have followed.  I just don't use the coach long enough to make the necessary changes to 12VDC needed to operate on inverter when dry camped...which we do a lot on National Parks.

Now, once the Norcold dies, I'll have to revisit the costs of each and go from there.

Peter
Title: Re: Dometic RM 7130 refridgerator won't cool below 41 degrees
Post by: John Haygarth on May 23, 2012, 06:48:22 pm
I have done it too and glad as it has made service etc a lot easier and it works so smooth without the worry of outside temps affecting it. Lucky me was able to make that pantry which Ruth thinks is great--more stuff to pack!!
John H
Title: Re: Dometic RM 7130 refridgerator won't cool below 41 degrees
Post by: Jerry Whiteaker on May 24, 2012, 12:52:07 am
Thanks to all for the suggestions. Tried running the unit on propane and refer temp dropped to 37 degrees.  switched back to electric and refer temp went back to 41.  Had a full bag of ice in one of the freezer shelves and removed that to see if air circ in the freezer was affecting the refer temp. After removal refer temp dropped to 37 on electric. Can't tell you why but happy with the results. ;D
I believe that I read somewhere that an absorption refrigerator will not cool as well on electric if the AC voltage is low, and that propane does not cool as well at high altitudes as at low altitudes.  In both cases less heat is produced which causes cooling to take place.  It's generally cooler at high altitudes, so the cooler propane flame may not be noticed.  Seems to make sense, so use what works the best.
Title: Re: Dometic RM 7130 refridgerator won't cool below 41 degrees
Post by: Caflashbob on May 24, 2012, 02:03:45 am
I believe that I read somewhere that an absorption refrigerator will not cool as well on electric if the AC voltage is low, and that propane does not cool as well at high altitudes as at low altitudes.  In both cases less heat is produced which causes cooling to take place.  It's generally cooler at high altitudes, so the cooler propane flame may not be noticed.  Seems to make sense, so use what works the best.


Interesting points
Title: Re: Dometic RM 7130 refridgerator won't cool below 41 degrees
Post by: Jim Frerichs on June 04, 2012, 09:41:53 pm
I just got a fan off ebay.  Hooked it up but have not had it on the road yet.  "Dometic/Norcold refrigerator Fan for RV 12 volt"  $15.40 plus $2.60 Shipping item # 250905640959.  Blows air into fins in back of unit at top.  Hooks right into the light switch/ constant hot.  I tried the small battery fans and they seem to help....    Dan.


Hi guys,

So... I decided to try two of the EBay offered double-fans in my Dometic NDR 1492 side-by-side because the freezer side always cooled to only about 10 F at best.  Well, I am amazed...the freezer went to 0 (as in zero) F with the fans mounted in front of the refrigerator fins while the refrigerator number setting and refrigerator side temps remained about the same.  I haven't run it long enough to know if it reduces/eleminates the frost concerns.

However, in my freezer, at last, really cold ice cream! Best purchase of the year and I have no connection with the Ebay offering.  No doubt that other computer/small muffin fans would work too. 

Jim
2002 U320
Title: Re: Dometic RM 7130 refridgerator won't cool below 41 degrees
Post by: Carol Savournin on June 05, 2012, 11:02:00 am
I believe that I read somewhere that an absorption refrigerator will not cool as well on electric if the AC voltage is low, and that propane does not cool as well at high altitudes as at low altitudes.  In both cases less heat is produced which causes cooling to take place.  It's generally cooler at high altitudes, so the cooler propane flame may not be noticed.  Seems to make sense, so use what works the best.

We are presently at 10,000 ft elevation in Leadville, CO ... and having the reverse problem with our Dometic NDR1492(?) side-by-side.  When we run the generator it will pull down to 40 and the freezer -8.  On propane, we are lucky to stay below 50.  I am all but certain that altitude is the problem.  Happily (for the fridge) we are leaving Thursday. 
Title: Re: Dometic RM 7130 refridgerator won't cool below 41 degrees
Post by: John Duld on June 05, 2012, 11:11:25 am
Sounds like the propane pressure regulator.
Title: Re: Dometic RM 7130 refridgerator won't cool below 41 degrees
Post by: Barry & Cindy on June 05, 2012, 09:43:33 pm
Propane fridges use a simple resistance heating element that gets hotter with higher voltage and vice versa.  The hotter the propane flame or electric heating element, generally the colder the fridge gets inside.

So Jerry is correct that low campground voltage can have an adverse effect on cooling. I guess that higher altitudes can lower gas pressure at the orifice and produce a smaller flame, which will also reduce cooling.
Title: Re: Dometic RM 7130 refridgerator won't cool below 41 degrees
Post by: gam on June 06, 2012, 10:18:38 am
On electric our fridge worked great,but on propane not so good. Checked flame at burner and it looked good. Removed orifice of burner jet and soaked it in alcohol as per Dometic. Reinstalled orifice and adjusted air,All is good. There isn't a drip leg in the gas line just before the burner so all the junk can end up in the orifice and restrict the gas flow. Gam
Title: Re: Dometic RM 7130 refridgerator won't cool below 41 degrees
Post by: RRadio on June 06, 2012, 11:31:49 pm
The air at high altitude is less dense and provides less oxygen for combustion from an equal volume of air as compared to air at low altitude. High temperature air is also less dense than low temperature air, but the difference is usually not as noticeable. When you burn fuel at high altitude you have to adjust the fuel to air mixture to compensate or else you'll have a rich mixture which doesn't burn completely or produce as much heat. You can probably put a smaller fuel jet in the burner and / or open the air adjustment further to correct the fuel mixture at high altitude. The manufacturer should have that information. You'll have to readjust the fuel mixture for low altitude if you come back down to sea level though. If you're only at high altitude for a short time it might not be worth making fuel mixture adjustments.

Scott
Title: Re: Dometic RM 7130 refridgerator won't cool below 41 degrees
Post by: Carol Savournin on June 07, 2012, 07:07:22 pm
Our recent issues with our Dometic fridge have resolved themselves.  The remedy was getting the heck out of Leadville, CO (10,200 ft) and heading into Utah.  The fridge was cooling nicely as long as we ran the generator, but would warm to 50 degrees on propane.  We are thinking that the regulator may be ready for a change, as it is 10 years old ... but for now all is well at the normal altitudes.
Title: Re: Dometic RM 7130 refridgerator won't cool below 41 degrees
Post by: Peter on May 12, 2022, 04:18:43 pm
I have read it is imperative to keep your dometic fridge level during operation. Is this also the case when the fridge is off?
My coach sometimes doesn't sit on the most level ground during the off season...
Title: Re: Dometic RM 7130 refridgerator won't cool below 41 degrees
Post by: wolfe10 on May 12, 2022, 04:20:58 pm
Storing out of level is not a problem.  Running it out of level IS a problem.

Even running for 5 minutes out of level significantly raises boiler temperature and shortens cooling unit life and can permanently reduce cooling capacity due to blockage of cooling tubes.
Title: Re: Dometic RM 7130 refridgerator won't cool below 41 degrees
Post by: Roger & Susan in Home2 on May 12, 2022, 09:08:06 pm
Hmmm... 5 minutes = 0.0833333333 degrees. Which is 0.105" out of plumb in 6 ft.

Perhaps Brett meant to say 5 degrees, typically the max out of level allowed for the newer LP refrigerators. Probably less than that for a 20 yr old LP refrigerator
Title: Re: Dometic RM 7130 refridgerator won't cool below 41 degrees
Post by: Geodmann on May 12, 2022, 10:31:07 pm
I read it that way at first too.  I think what Brett meant was running the fridge out of level for even as little as 5 minutes is enough to cause it to overheat and possibly damage it.
Title: Re: Dometic RM 7130 refridgerator won't cool below 41 degrees
Post by: Peter on May 12, 2022, 11:03:56 pm
I would love to know how folks keep their fridge level ALL the time??!
Title: Re: Dometic RM 7130 refridgerator won't cool below 41 degrees
Post by: craneman on May 12, 2022, 11:59:08 pm
He is referring to when parked. When moving not an issue.
Title: Re: Dometic RM 7130 refridgerator won't cool below 41 degrees
Post by: oldguy on May 13, 2022, 12:07:41 am
That's one of the reasons to go with a residential fridge as they work when not level.
Title: Re: Dometic RM 7130 refridgerator won't cool below 41 degrees
Post by: Jeff & Sandy on May 13, 2022, 06:48:24 am
I would love to know how folks keep their fridge level ALL the time??!

Your HWH should do it for you. If you can't get level on a campsite I'd change sites if possible. I switched to a residential fridge but I still want to be level.
Title: Re: Dometic RM 7130 refridgerator won't cool below 41 degrees
Post by: wolfe10 on May 13, 2022, 08:03:23 am
Hmmm... 5 minutes = 0.0833333333 degrees. Which is 0.105" out of plumb in 6 ft.

Perhaps Brett meant to say 5 degrees, typically the max out of level allowed for the newer LP refrigerators. Probably less than that for a 20 yr old LP refrigerator

Sorry I was not clearer.  I went back and edited my post.  It now reads more clearly:

"Even running for 5 minutes out of level significantly raises boiler temperature and shortens cooling unit life and can permanently reduce cooling capacity due to blockage of cooling tubes."