Fridge question/help

Hostile2camp · 07-10-2018, 09:43 PM

2014 23ikss Dometic fridge.
-When on propane, both the freezer and fridge get cold
-When on electric, freezer gets cold but fridge stays warm (back fins stay warm)
-Checked thermistor and it is in proper place and fridge works on gas and the camper is level.

I know people say give it hours (which I have)or even days when on electric, but before this issue the fins in back would start to feel cooler after 30mins and now they just stay ambient.

rockfordroo · 07-10-2018, 10:35 PM

The gas burner puts out 35% more BTU's than the electric element (1500 vs 1108). Efficiency of the unit goes up with a hotter heat source. Efficiency is the related to the difference between the hot side (burner/element) and the cold side (the coils on the back of the unit); the greater this temperature difference, the more efficient the cycle. Given that the ambient temperature around the coils on the back is about the same when you change heat sources, the gas burner, being hotter, gives you better efficiency. It may be just enough to get the fridge cold.

Since you can't raise the temperature of the electric heating element, your other option is to cool the coils further. Suggest you install a couple of computer fans to blow up across the coils.

Hostile2camp · 07-11-2018, 07:02 AM

Thank for the reply. So it seems like maybe the electric coil may not be getting as hot or efficient as it used to? Do you know of an suggestions to make that hotter or to unsure its doing what it should be?

rockfordroo · 07-11-2018, 07:17 AM

Quote:

Originally Posted by Hostile2camp

Thank for the reply. So it seems like maybe the electric coil may not be getting as hot or efficient as it used to? Do you know of an suggestions to make that hotter or to unsure its doing what it should be?

You can't make it hotter, you can only make the other side cooler, i.e., install some fans.

I doubt the efficiency has "changed." But if the outside temperature has gone up, that warms up the coil side, and use of the lower electric element (as opposed to the hotter gas) cools down the heating side. So efficiency goes down.

SeaDog · 07-11-2018, 08:04 AM

X2 what rockfordroo said. here is an example of one kit aval. https://www.amazon.com/Valterra-A10-.../dp/B002N5YDG2

Mmcglynn264 · 07-11-2018, 08:10 AM

Is it possible that the electric element is bad and not getting as hot as it used to? I'm just learning about these kind of refrigerators myself, so I'm just curious of the element could be the issue and I also wonder if it's easily replaceable.

rockfordroo · 07-11-2018, 08:30 AM

Quote:

Originally Posted by Mmcglynn264

Is it possible that the electric element is bad and not getting as hot as it used to? I'm just learning about these kind of refrigerators myself, so I'm just curious of the element could be the issue and I also wonder if it's easily replaceable.

Electric elements typically either work or they don't. I believe it's a "single wire" element, so I highly doubt it's not getting as hot as it used to. Although I could be wrong, as I've never actually seen the inside of one.

SeaDog · 07-11-2018, 08:40 AM

A quick search found that the Dometic 120V heating element is 325 watts did not find any options for larger or smaller elements.

rockfordroo · 07-11-2018, 01:17 PM

Quote:

Originally Posted by SeaDog

A quick search found that the Dometic 120V heating element is 325 watts did not find any options for larger or smaller elements.

For those following along: 325 watts = 1108 BTU's.

Hostile2camp · 07-11-2018, 04:49 PM

This is the stock Dometic that came with the 2014 23ikss. Does the electric and the gas use the same system or are there two (like one for the fridge and a separate one for the freezer)? What would cause the electric to no longer work as well and not be able to cool off the fridge part? This just started happening this year with the electric not cooling the fridge. The outside temps aren't any hotter then they had been and I am in the same altitude as well so I can cross those two off. Could it for instance have lost some of the fluids that create the cooling ( I don't notice any leaks)? Thanks for the replies guys!

Hostile2camp · 07-11-2018, 07:06 PM

One other question. What are the fins that sit inside the refrigerator portion on the top (thermistor attaches to them)? Are they just basically a heatsink or are they some other part of the process that ammonia would pass through?

**Flybob** · 07-11-2018, 07:16 PM

There is only one system ( think in series). The effectiveness of the fridge depends on the difference in temp between the hot side and the cooled side. In hot weather it is harder to get a large difference using electric unless you add a way to move air over the fins to cool them. Try a fan on the exhaust side to draw the hot air out. The system is not as efficient as your fridge at home so opening an empty fridge and feeling the fins is not a good judge of performance,

Reprise · 07-11-2018, 08:33 PM

I apologize in advance for the thread hijack (but still think it better to ask here, rather than create another thread)...

I've read this thread with some interest, especially the part about the propane gas side being more efficient / cooling faster.

I've always steered toward kicking off the pre-trip cooling on the electric side, in order to save propane for when electric wasn't available (and knowing that once cool, very little propane is subsequently used in order to keep it cool.)

My question: Almost all of this thread concerns Dometic fridges. Does the same gas vs electric efficiencies apply to Norcold products as well? (I'm talking actual, not theoretical - I know both are absorption-based, both have boilers, etc.) Because if so, then it may be better for me to start the initial cooldown on gas, going forward.

Thanks in advance for replies - and again - sorry for the hijack!

rockfordroo · 07-11-2018, 08:44 PM

Quote:

Originally Posted by Reprise

I apologize in advance for the thread hijack (but still think it better to ask here, rather than create another thread)...

I've read this thread with some interest, especially the part about the propane gas side being more efficient / cooling faster.

I've always steered toward kicking off the pre-trip cooling on the electric side, in order to save propane for when electric wasn't available (and knowing that once cool, very little propane is subsequently used in order to keep it cool.)

My question: Almost all of this thread concerns Dometic fridges. Does the same gas vs electric efficiencies apply to Norcold products as well? (I'm talking actual, not theoretical - I know both are absorption-based, both have boilers, etc.) Because if so, then it may be better for me to start the initial cooldown on gas, going forward.

Thanks in advance for replies - and again - sorry for the hijack!

As I stated previously, the Dometic is more efficient on gas because the gas side puts out more BTU's than the electric side. I have been unable to find any info on the BTU outputs of the gas and electric for Norcolds. I would GUESS that they are similar, but I don't know.

If you are able to find the BTU values for the Norcold, you'll know which is more efficient.

Be aware, however, that just because one side is more efficient than the other side at cooling does NOT mean it's cheapest. There are folks in the northeast who have reported that they are paying something like 24 cent/kw-hr for electricity, so they find it cheaper to run on gas. But if you're only paying 11 cent/kw-hr (or you get it free with your campsite cost), then electric mayl be cheaper, even if it's not quite as efficient. Of course, the price of gas in your area will impact this, too.

You may also like: