Freezer working, fridge is not.

[wdk450]

Here is the easiest method to check out if the ammonia adsorption refrigerator cooling unit is working. The only possible drawback is if the electric heating element is NOT working (this only happens about 5% of the time per another RV refrigeration website). This procedure is copied from the RVCoolingUnit.com website, "Tech Information" link at the bottom of the main home page.

Advanced testing method : Dometic recommends the following method for testing the cooling unit: this can also be used to test Norcolds
1. Make sure the unit is level, do not assume.
2. Hook up the two wires of the heating element directly to a known good 110 volt source, in effect bypassing the thermostat and control systems. To do this, locate the two wires coming from the 110 volt AC heating element. The heating element is located in the cylindrical tin casing surrounding the burner flue, and is accessible through the removable panel on the side of the casing. If you have a three way refer there should be two elements side by side. The 12 volt element can be identified by noting the way the wires are connected. The 12 volt element has one wire connected directly to the element and the other wire connects with a spade type of terminal for the Dometic units. The 110 volt element has both wires connected directly to the element. Also, if you fully remove the elements, the voltage will be stamped on the casing.
Disconnect the two wires at the terminal block and connect these wires directly to a 110 volt source. If you are not comfortable or sure about what you are doing, then this test is best left to your RV Technician.
3. Place a thermometer in a glass of water and place in the food (not Freezer) compartment. It is important to use the glass of water for this test as it equalizes the temperature reading.
4. After 12 hours the temperature should be in the 30's deg. F or less.
5. After 24 hours the temperature should be between the low 20's to low 30's maximum. If these temperatures are not reached and maintained during the hottest part of the day, then the cooling unit is faulty and should be replaced.
6. Only confirm a good cold lower food (not freezer) zone temperature, because sometimes a bad cooling unit can still freeze and make ice. The food zone(lower section) is the tail end of the cooling cycle, so a good cooling unit will be able to cool and maintain all the way through the unit, top to bottom.


This MIGHT be a helpful addition to the Heartland Service Manuals section.
Advanced testing methods Dometic recommends the following method for testing the cooling unit which will confirm: this can also be used to test Norcolds
1. Make sure the unit is level, do not assume.
2. Hook up the two wires of the heating element directly to a known good 110 volt source, in effect bypassing the thermostat and control systems. To do this, locate the two wires coming from the 110 volt AC heating element. The heating element is located in the cylindrical tin casing surrounding the burner flue, and is accessible through the removable panel on the side of the casing. If you have a three way refer there should be two elements side by side. The 12 volt element can be identified by noting the way the wires are connected. The 12 volt element has one wire connected directly to the element and the other wire connects with a spade type of terminal for the Dometic units. The 110 volt element has both wires connected directly to the element. Also, if you fully remove the elements, the voltage will be stamped on the casing.
Disconnect the two wires at the terminal block and connect these wires directly to a 110 volt source. If you are not comfortable or sure about what you are doing, then this test is best left to your RV Technician.
3. Place a thermometer in a glass of water and place in the food compartment. It is important to use the glass of water for this test as it equalizes the temperature reading.
4. After 12 hours the temperature should be in the 30's deg. F or less.
5. After 24 hours the temperature should be between the low 20's to low 30's maximum. If these temperatures are not reached and maintained during the hottest part of the day, then the cooling unit is faulty and should be replaced.
6. Only confirm a good cold lower food zone temperature, because sometimes a bad cooling unit can freeze and make ice. The food zone(lower section) is the tail end of the
cooling cycle so a good cooling unit will be able to cool and maintain all the way through the unit, top to bottom.

 

[mlpeloquin]

Bill - As usual you provide great information. This two day ago with temperatures at 105F the refrigerator set at 9 maximum setting, the refrigerator was at 9C or 48F. The freezers were at -9C or 15.8F and -8C or 19.4F. So the ice cream was a bit soft, but everything was still good in the freezers, but the refrigerator should be between 1.66C or 35F to 3.33C or 38F. Since we purchased the fifth wheel, the refrigerator has never been down to that temperature when the outside temperature was above 90F. I work with degrees C, because I installed the digital temperature monitors I believe you installed and recommended in another post. In the future, our next fifth wheel will have a residential in it. Not much you can do with this type of refrigerator.

 

[Lynn1130]

As I said. They do not work well in temps above 90 F. I live in Arizona and can tell you from experience that if the outside temp is 90+F (and it is 118.5 F here right now) you will not see temps below 50 F+ in the refridg no matter what the manufacturer tells you. They just can do it!

 

[JohnD]

I wonder if running the fridge on gas instead of electric in real hot temps would cool better than electric . . .

Or maybe electric instead of gas

We also have one of those digital clocks with indoor/out door temps displayed in the camper, but when we are on the road we put the outdoor sensor in the fridge and the clock/thermometer in the truck so we can monitor the fridge temps when rollin'.

Got that idea from someone at the 2016 Las Vegas HOC National Rally to do that.

I run the fridge with gas while on the road.

It usually runs around 30 degrees.

 

[wdk450]

I wonder if running the fridge on gas instead of electric in real hot temps would cool better than electric . . .

Or maybe electric instead of gas

We also have one of those digital clocks with indoor/out door temps displayed in the camper, but when we are on the road we put the outdoor sensor in the fridge and the clock/thermometer in the truck so we can monitor the fridge temps when rollin'.

Got that idea from someone at the 2016 Las Vegas HOC National Rally to do that.

I run the fridge with gas while on the road.

It usually runs around 30 degrees.

John:
This is a GREAT idea if you have a problem with the refrigerator intermittently blowing the 12 volt branch fuse for the refrigerator/stove light-fan. like I did. I fought this problem for about 6 months before finally finding the red 12 volt supply wire winding TIGHTLY around a grounded metal corner of the refrigerator base, wearing through the wire insulation, and intermittently blowing the fuse as the rig vibrated down the road.

 

[Lynn1130]

I wonder if running the fridge on gas instead of electric in real hot temps would cool better than electric . . .

No. I have tried it both ways and it makes no difference. I asked my RV service people that question also and their answer was "makes no difference".

 

[Dreamer7]

No. I have tried it both ways and it makes no difference. I asked my RV service people that question also and their answer was "makes no difference".

Ok, thanks Lynn.

 

[wdk450]

It makes no difference between propane gas heat or electric heating element heat IF the gas flame is correctly adjusted, if there is no debris blocking the flame/airflow, etc. The electric heating element is pretty much go or no-go, and is thus preferred for testing purposes.

 

[wdk450]

It makes no difference between propane gas heat or electric heating element heat IF the gas flame is correctly adjusted, if there is no debris blocking the flame/airflow, etc. The electric heating element is pretty much go or no-go, and is thus preferred for testing purposes.

Well, this is a post that is going to somewhat contradict one of my previous posts (above). We have been going through a high heat siege here in Porterville, Ca. between Bakersfield and Fresno. My outside thermometer has been showing between 105 and 108 every afternoon. A couple of days ago I saw that the Dometic NDR1292 was not keeping cool enough. I normally run it on electric power, augmenting the refrigerator inside in the hot afternoons with blue ice blocks. Yesterday afternoon I switched to gas power to see if that cooled better. Overnight the refrigerator temperature came down to 1 degree celsius (34 F?) even though the outside temperature didn't get much below 80 overnight.

The heating elements are 2 - 60 volt, 210 watt elements wired in series for 420 watts. I looked on E-Bay and found that RVCoolingUnit Warehouse has a special on the double heating element for this refrig right now. I didn't see the same special on their website for the heaters.

 

[Lynn1130]

Overnight the refrigerator temperature came down to 1 degree celsius (34 F?) even though the outside temperature didn't get much below 80 overnight.

Even 80 will cool better than 105. I start the fridge when I pull it out front to begin loading. That usually is in the AM and temps around 105. The fridge does not cool below 45-55 but the freezer will get to 15-20. Sometimes lower. During the night our temps drop into the 80s and the fridge will cool to 35-40. As the heat outside get worse the fridge heats back up. I also have a fan on the cooling unit in the outside compartment running on 12V. That makes little difference when it is 100 or better but boy when it is 60 outside is will bring the fridge down to 25. Too cold and I have to shut it off.

I have tried using only gas or only electric and it makes no difference here.

 

[wdk450]

Even 80 will cool better than 105. I start the fridge when I pull it out front to begin loading. That usually is in the AM and temps around 105. The fridge does not cool below 45-55 but the freezer will get to 15-20. Sometimes lower. During the night our temps drop into the 80s and the fridge will cool to 35-40. As the heat outside get worse the fridge heats back up. I also have a fan on the cooling unit in the outside compartment running on 12V. That makes little difference when it is 100 or better but boy when it is 60 outside is will bring the fridge down to 25. Too cold and I have to shut it off.

I have tried using only gas or only electric and it makes no difference here.

I removed both the upper and lower vent covers while parked to less restrict cooling airflow. I too have a 12 volt DC desk-type fan on the lower outside compartment blowing in, with the fan aimed up at a 45 degree angle. The fan is supported with mechanics wire. Up top, I have a cardboard baffle wedged between the refrig and the outside enclosure tight to and ending at the top side of the square condenser fins. Somewhere I remember reading that although the condenser is at the top of the cooling unit stack, proper heat exchange airflow across the condenser is the most important airflow point in the cooling unit, as the condenser is where all of the refrigerant ammonia is produced from the boiler vapor. I am thinking about putting a set of computer CPU fans under or on top of the condenser, the entire width of the condenser.

Something needs to be done about the top vent to let more air out, as with the height of the refrigerator and condenser, only about 3 inches of vent cutout space is available to vent out the hot heat exchange air. I may put in hardware cloth screen in place of the top 3 inches of plastic on the vent cover.

On edit: Still on propane, outside thermometer says 99 degrees, refrigerator thermometer says 2.5 degrees C.

 

[Dreamer7]

Here is the easiest method to check out if the ammonia adsorption refrigerator cooling unit is working. The only possible drawback is if the electric heating element is NOT working (this only happens about 5% of the time per another RV refrigeration website). This procedure is copied from the RVCoolingUnit.com website, "Tech Information" link at the bottom of the main home page.

Advanced testing method : Dometic recommends the following method for testing the cooling unit: this can also be used to test Norcolds
1. Make sure the unit is level, do not assume.
2. Hook up the two wires of the heating element directly to a known good 110 volt source, in effect bypassing the thermostat and control systems. To do this, locate the two wires coming from the 110 volt AC heating element. The heating element is located in the cylindrical tin casing surrounding the burner flue, and is accessible through the removable panel on the side of the casing. If you have a three way refer there should be two elements side by side. The 12 volt element can be identified by noting the way the wires are connected. The 12 volt element has one wire connected directly to the element and the other wire connects with a spade type of terminal for the Dometic units. The 110 volt element has both wires connected directly to the element. Also, if you fully remove the elements, the voltage will be stamped on the casing.
Disconnect the two wires at the terminal block and connect these wires directly to a 110 volt source. If you are not comfortable or sure about what you are doing, then this test is best left to your RV Technician.
3. Place a thermometer in a glass of water and place in the food (not Freezer) compartment. It is important to use the glass of water for this test as it equalizes the temperature reading.
4. After 12 hours the temperature should be in the 30's deg. F or less.
5. After 24 hours the temperature should be between the low 20's to low 30's maximum. If these temperatures are not reached and maintained during the hottest part of the day, then the cooling unit is faulty and should be replaced.
6. Only confirm a good cold lower food (not freezer) zone temperature, because sometimes a bad cooling unit can still freeze and make ice. The food zone(lower section) is the tail end of the cooling cycle, so a good cooling unit will be able to cool and maintain all the way through the unit, top to bottom.


This MIGHT be a helpful addition to the Heartland Service Manuals section.


Advanced testing methods Dometic recommends the following method for testing the cooling unit which will confirm: this can also be used to test Norcolds
1. Make sure the unit is level, do not assume.
2. Hook up the two wires of the heating element directly to a known good 110 volt source, in effect bypassing the thermostat and control systems. To do this, locate the two wires coming from the 110 volt AC heating element. The heating element is located in the cylindrical tin casing surrounding the burner flue, and is accessible through the removable panel on the side of the casing. If you have a three way refer there should be two elements side by side. The 12 volt element can be identified by noting the way the wires are connected. The 12 volt element has one wire connected directly to the element and the other wire connects with a spade type of terminal for the Dometic units. The 110 volt element has both wires connected directly to the element. Also, if you fully remove the elements, the voltage will be stamped on the casing.
Disconnect the two wires at the terminal block and connect these wires directly to a 110 volt source. If you are not comfortable or sure about what you are doing, then this test is best left to your RV Technician.
3. Place a thermometer in a glass of water and place in the food compartment. It is important to use the glass of water for this test as it equalizes the temperature reading.
4. After 12 hours the temperature should be in the 30's deg. F or less.
5. After 24 hours the temperature should be between the low 20's to low 30's maximum. If these temperatures are not reached and maintained during the hottest part of the day, then the cooling unit is faulty and should be replaced.
6. Only confirm a good cold lower food zone temperature, because sometimes a bad cooling unit can freeze and make ice. The food zone(lower section) is the tail end of the
cooling cycle so a good cooling unit will be able to cool and maintain all the way through the unit, top to bottom.

Thank you for for this information!

Katy

 

[mlpeloquin]

To make sure the I was level for my refrigerator, I set my I-Phone with the bubble level in the freezer. When it said level I put it into the other freezer on the left side. Both said level. Then I reprogrammed my auto level for that being the level reference.

 

[wdk450]

To make sure the I was level for my refrigerator, I set my I-Phone with the bubble level in the freezer. When it said level I put it into the other freezer on the left side. Both said level. Then I reprogrammed my auto level for that being the level reference.

With the modern ammonia absorption refrigerators made within about the last 15 years, the boiler has been redesigned, and levelling is not so critical. The guidelines in the newer refrigerator manuals say that is the RV is level enough for you to walk around comfortably, the refrigerator is safe from out-of-level cooling unit internal plugging.

 

[mlpeloquin]

With the modern ammonia absorption refrigerators made within about the last 15 years, the boiler has been redesigned, and levelling is not so critical. The guidelines in the newer refrigerator manuals say that is the RV is level enough for you to walk around comfortably, the refrigerator is safe from out-of-level cooling unit internal plugging.

I have read that too. My fifth wheel is fairly level after doing this. If I stayed at parks as long as you do, I would remove the bottom vent cover add the fans at the bottom as well, but removing the vent at the top is something I have not done. The hot air get trapped and has to hit the top and travel down to exit. We will be going out in a week or so and will try that. Bill, you have a lot of good advice.

 

[JohnD]

My new criteria for leveling the trailer is if the swing-out glass door on our shower stays open by itself.

 

[mlpeloquin]

My new criteria for leveling the trailer is if the swing-out glass door on our shower stays open by itself.

Or the bathroom door!

 

[Lynn1130]

My new criteria for leveling the trailer is if the swing-out glass door on our shower stays open by itself.

That has always been mine.

 

[Dclaws54]

I was having a similar problem with my four door norcold unit. But the refrigerator part was not cooling after outside temps reached 90 or above. So I go to put a fan at the top vent and what did I find ? The factory had put a piece of plywood that was blocking 2/3 s of the vent. Out with the plywood and found 2 fans below it one not working because of a mud dobbers nest. Cleaned it , fan starting working . Refrigerator works perfectly now.


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[Dclaws54]

I was having a similar problem with my four door norcold unit. But the refrigerator part was not cooling after outside temps reached 90 or above. So I go to put a fan at the top vent and what did I find ? The factory had put a piece of plywood that was blocking 2/3 s of the vent. Out with the plywood and found 2 fans below it one not working because of a mud dobbers nest. Cleaned it , fan starting working . Refrigerator works perfectly now.


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Update : over 100 f here in central Texas today My norcold 1210 is holding steady at 35 f with no shade on it.


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