set a Dometic 2-way Fridge for 'always on Shore Power'...

[Reverse_snowbird]

Originally Posted by chriscowles

The water heater switches automatically? That's not my experience. My control panel has independent switches for gas and electric. You can have either, or both.

If we have power we leave it in electric mode unless showering, in which case we turn on the propane for faster recovery. When the propane is off, the electric element keeps it more than hot enough for small volume use like cooking and eating hands.

You are correct. Sorry. Wasn't thinking. Ours operated automatically on electric unless we turned on the gas switch. Then as you said, we could have either or both.

[Scrapper]

My DM2652 refrigerator has the same buttons as your picture in post #10. The ON/OFF button when pushed in (led lit) turns on the main 12vdc power to the control boards. The AUTO/GAS button turns on the 120vac heater when in the AUTO position (button in/led on). The AUTO/GAS button when in the out position (AUTO led off) turns on gas operation. I can force my fridge to use gas just by turning off AUTO (led off).


Since your RM2652 is the same as my DM2652 maybe this service manual will help. BTW RM2652 is an older version of the DM2652 which is an older version of DMR2652.

[formerFR]

I have the owners manual, and have referenced it's 'confusing' or 'unclear' language several times in these posts - what is 'unclear' is the usage of the wording of "the system will choose what power source" or something similar when you are 'NOT' on the 'Auto' button - making it sound as if the button being 'OUT' or in the 'off' position does not 'necessarily' mean that 'Gas' will be used - for instant, if you are out of gas, and yet you DO have 120v power. I suppose that's what it means - it defaults BACK to 120v power EVEN IF you let the button stay 'OUT' wanting propane to be used - if the propane then runs out.

[Scrapper]

Here's what my manual has;


AUTOMATIC ENERGY SELECTOR SYSTEM
The refrigerator is equipped with an automatic energy selector system. The user turns the refrigerator on and then, the refrigerator automatically selects the most suitable energy source available, either 120 VAC or LP gas operation. The system can be set by the user to be fully automatic (AUTO mode is selected) or to operate on LP gas only (AUTO mode is off).

This indicates that you have to have the ON/Off switch turned ON for the fridge to work in either mode. I also don't understand their wording here when they go on to say it can be forced to use gas by turning AUTO off. As a guess it may do this but when the AUTO switch is turned off manually then it forces gas mode.


MODES OF OPERATION
AUTO MODE - AES/AUTO MODE
When operating in AUTO - AES/AUTO mode, the AUTO - AES/AUTO mode indicator lamp is illuminated. The control system will automatically select between AC and GAS operation. AC has priority over GAS. Should AC become unavailable, the system automatically switches to GAS.
As soon as AC becomes available again, the control will switch back to AC regardless of the status of the GAS operation.

This may be where you are getting confused. I can verify that it does go into gas mode when you lose 120vac power as I have experienced it. I can also verify that it goes into gas mode when you turn off the AUTO button while having gas turned on at the tanks. I turn AUTO mode off at the beginning of the season then again in July as a test.

If the CHECK indicator lamp is illuminated the controls have failed to ignite the burner in the GAS mode. To restart an ignition attempt with the CHECK lamp illuminated (or to turn off the CHECK lamp), press the ON/OFF button OFF and back ON again. The control system activates the ignition system and makes three attempts to light the burner for a period of approx. 45 sec. at two minutes interval. Should 120 VAC become available while the CHECK indicator lamp is on, the CHECK lamp will not turn off until the ON/OFF button is pressed OFF and then ON again.


LIMP MODE OF OPERATION
In the event of a failure of a major operating component, the control system will continue to operate the cooling system. RM2351, RM2451, RM2551, DM2652 & DM2852
If the control can not read the temperature sensor and control the preset temperature, the control will run the cooling unit continuously at the energy source available. The refrigerator will continue to operate in this mode indefinitely - or - until a new sensor is installed and the system reset.

[formerFR]

Originally Posted by Scrapper

...
LIMP MODE OF OPERATION
In the event of a failure of a major operating component, the control system will continue to operate the cooling system. RM2351, RM2451, RM2551, DM2652 & DM2852
If the control can not read the temperature sensor and control the preset temperature, the control will run the cooling unit continuously at the energy source available. The refrigerator will continue to operate in this mode indefinitely - or - until a new sensor is installed and the system reset.

right, but this does not allude to the operation of my RM-2652, though it's really the 'idea' I had that might give the fridge the operation it needs, while on 120v power, even IF the controls lost 12v power...

but, since it's not listing 'my' fridge, I can only assume that's not the case for mine.

But, here's the real quandary:

Will the second button, when NOT pressed, which is apparently for 'Gas' Mode, or as my owners manual instructions calls 'MANUAL MODE', cause the power source to 'ALWAYS' be 'gas'(?), or what IF 'gas' is not present, or the igniter can't light, will it switch THEN to 120v power, IF it is present???

If not, then why does the manual say that in the MANUAL MODE " the refrigerator will run continuously on the energy source selected by the control system." if there is no 'other' option??
It almost sounds like it COULD choose 120v power, if available, even IF the MANUAL MODE is selected, but 'Gas' is not available, or cannot ignite.

If THAT'S the case, then it seems that this 'second' button on the panel is really simply a 'PREFERENCE' button, meaning that do you want the 'controller' to choose 120v over 'Gas', or 'Gas' over 120v?

At least, that's the way it seems to be reading. Tomorrow I am going to run a test. I'll have shore power. I'll go into 'Manual Mode' by 'unpressing' the 'AUTO' mode, otherwise known as 'Gas'. But, I'll not have any propane connected for the system to use, giving it the opportunity to 'try' to light. When it cannot, it will then light the 'CHECK' indicator....

now, then, the question will be: will it then 'revert' to the present 120v power?

[Scrapper]

Originally Posted by formerFR

right, but this does not allude to the operation of my RM-2652, though it's really the 'idea' I had that might give the fridge the operation it needs, while on 120v power, even IF the controls lost 12v power...

but, since it's not listing 'my' fridge, I can only assume that's not the case for mine.

But, here's the real quandary:

Will the second button, when NOT pressed, which is apparently for 'Gas' Mode, or as my owners manual instructions calls 'MANUAL MODE', cause the power source to 'ALWAYS' be 'gas'(?), or what IF 'gas' is not present, or the igniter can't light, will it switch THEN to 120v power, IF it is present???

If not, then why does the manual say that in the MANUAL MODE " the refrigerator will run continuously on the energy source selected by the control system." if there is no 'other' option??
It almost sounds like it COULD choose 120v power, if available, even IF the MANUAL MODE is selected, but 'Gas' is not available, or cannot ignite.

If THAT'S the case, then it seems that this 'second' button on the panel is really simply a 'PREFERENCE' button, meaning that do you want the 'controller' to choose 120v over 'Gas', or 'Gas' over 120v?

At least, that's the way it seems to be reading. Tomorrow I am going to run a test. I'll have shore power. I'll go into 'Manual Mode' by 'unpressing' the 'AUTO' mode, otherwise known as 'Gas'. But, I'll not have any propane connected for the system to use, giving it the opportunity to 'try' to light. When it cannot, it will then light the 'CHECK' indicator....

now, then, the question will be: will it then 'revert' to the present 120v power?

Since you need to see your model number on the documents, even though the DM2652 is a newer version of the RM2652, here are some I found that specify the RM2652.


The two owners manual say pretty much the same thing, just some of it is different in wording. Also included is a Service Manual for the RM2652.


Dometic no longer makes the RM2652 so there are no longer any documents for this model on their website.


I'm off to my camper so you my seasonal camper so depending on how well the cell service or wifi works you may not hear from me til later in the week.

[formerFR]

I have the owners manual, but it says nothing about this 'limp mode' you speak of, which could be a difference between the two models. If it's already a part of my unit, there's nothing in the manual to allude to that, though it wish it were.

[formerFR]

I'm doing a test right now, as we are leaving for church...

I have 120v power.
I have no propane.
I have pushed the 'GAS' button, instead of the 'Auto' mode

the 'CHECK' indicator has not come on.

We'll see if the fridge is stilling operating, cooling, when we return in several hours...

[my thought is that if the manual is reading as I think it is, the pressing of the button OUT to 'GAS', really means 'MANUAL MODE'. If there is no propane, though, I suspect, or even hope, that, as the manual says, the Control Panel will 'choose' the power source, which obviously would ONLY be 120v power, since that's all that is available.]

we'll see...

[formerFR]

the CHECK light indicator finally did come on, after quite a long time...

we'll see if these confirms that the Fridge is NOT going to then use the available 120v power, or if it does... melted ice may help to confirm one way or the other.

[formerFR]

it doesn't look good, so far.... : /

[MR.M]

With out 12 volts the fridge will not run on 120 . with out 12 volts the AC will not run 12 volts needed for t/stat and control board . the best thing for a camper parked all the time is to have propane so if power goes out then fridge will still run , same with having a battery with out 120 at least lights , fridge , water heater can still run . so to make the most out of your rv a battery S/B installed and propane to get the most out of your unit . if power goes out the RV will be a lifeboat

[MR.M]

Originally Posted by formerFR

I'm doing a test right now, as we are leaving for church...

I have 120v power.
I have no propane.
I have pushed the 'GAS' button, instead of the 'Auto' mode

the 'CHECK' indicator has not come on.

We'll see if the fridge is stilling operating, cooling, when we return in several hours...

[my thought is that if the manual is reading as I think it is, the pressing of the button OUT to 'GAS', really means 'MANUAL MODE'. If there is no propane, though, I suspect, or even hope, that, as the manual says, the Control Panel will 'choose' the power source, which obviously would ONLY be 120v power, since that's all that is available.]

we'll see...

If you have it set to gas and not auto it will not auto switch . hence the auto button

[formerFR]

right, but I'm not testing the fact that the camper is designed to have different power sources at different times for different reasons, but the question of 'will' an RV fridge act just like a home's fridge when you are parked FULL-TIME always on 120v Shore Power and no propane or propane bottles even attached to the rig. I DON'T want it to 'switch' to gas, that's the point, but I also don't need a 'light' on the front to continually tell me that it's in 'AUTO' mode - it would seem to me that you would want to see that indicator when you're on PROPANE, so that you KNOW you're using propane, and not vice versa...

But, regardless, these are just 'tests' that I am running to determine if the owner manual's 'vague' wording and terms, like 'MANUAL MODE', do what the manual describes. One vagueness is the usage of the term 'what power source the control system decides to use" or similar wording. If you 'have' to push the second button OUT to go into 'Gas', or the 'MANUAL MODE', what other 'source' of power can it 'decide' to use?? Only 120v is also available, but it looks like that then is no longer a 'choice', since you have to press the button for 'AUTO' mode for that power source to happen....

I think they need to look at their manual's wording and how they describe how the fridge works. If you use the term 'Manual Mode', but yet there's nothing on the Control Panel that says 'Manual', it's confusing. Why would they NOT just use the same term/word that's on the Control Panel - 'GAS' ? Crazy.

But, it's not uncommon for owner manuals to be like that. Look at your RV's manual, and you may find the same 'vagueness' for a lot of things.

So, what I'm finding is this. If you want to use 120v electricity to operate your fridge 24/7, EVEN if you lose power, the only 'real' option is to press IN the 'AUto' button, which will then illuminate ALL THE TIME, even if you know and never intend to ever use propane, regardless of whether the system will 'try' to light it anyway. I was hoping for a 'override' for 120v 'Only' usage of the fridge.

[MR.M]

if you leave it in auto it will select 120 first and then propane . if on gas only then it will not search for 120 . but propane only . some fridge like nor cold has a control where you can choose auto, electric or gas . dometic does not as far as i know give you that option.

And i agree manuals are not always worded very well and can be confusing .

[5picker]

No. Without 12v (whether from the converter or a battery) it wont work on 120v AC.

[Scrapper]

Originally Posted by formerFR

I have the owners manual, but it says nothing about this 'limp mode' you speak of, which could be a difference between the two models. If it's already a part of my unit, there's nothing in the manual to allude to that, though it wish it were.

The second manual "RM2652 Owners Manual.pdf" does mention the limp mode.

Originally Posted by formerFR

the CHECK light indicator finally did come on, after quite a long time...

we'll see if these confirms that the Fridge is NOT going to then use the available 120v power, or if it does... melted ice may help to confirm one way or the other.

Both manuals state if there is no 12vdc power then the fridge will not work in either mode. When you have 120vac shore power your converter is handling the 12vdc required. If at any time you loose 120vac shore power for any reason the refrigerator will rely on the battery to supply the 12vdc power to operate the fridge on gas. Since you said you removed your battery then there is not any 12vdc power to fall back on to run it on gas if you loose 120vac shore power. If you loose 120vac the fridge will not operate from gas because you don't have a battery installed or have gas available. Once the 'Check' light comes on it will not go out until you turn the fridge off then back on.

Placing a penny on top of an ice cube will tell you if the fridge has stopped working long enough for the cube to start melting.

[formerFR]

hmmmm, maybe I missed it, but I saw no 'limp mode' mentioned in the 'second' link manual, though that manual is certainly different from mine, and even does say that you can either have it in 'Auto' mode, by pressing the second button, or 'Manual' mode, by not pressing the button. ('Gas', though, is the word on my Control Panel)...

I'm assuming that some 3-way or other brands allow for a 'Manual' mode for just 120v power, when you have it all the time, with no lights having to be lit the whole time.

[Scrapper]

Originally Posted by formerFR

hmmmm, maybe I missed it, but I saw no 'limp mode' mentioned in the 'second' link manual, though that manual is certainly different from mine, and even does say that you can either have it in 'Auto' mode, by pressing the second button, or 'Manual' mode, by not pressing the button. ('Gas', though, is the word on my Control Panel)...

I'm assuming that some 3-way or other brands allow for a 'Manual' mode for just 120v power, when you have it all the time, with no lights having to be lit the whole time.

Page 10, right column.

[formerFR]

I see.... sorry, I was looking at the 'second' RM2652 link.

I see that this is really only referencing the failure of the 'Temperature Sensor', and not any 12v failure, etc., and just continues to run the unit 'all the time' with no temp sensing capability, at least until you replace it with an operational one.

So, no, that 'limp mode' is really not what I would consider something to do with a 'power source' as we were discussing.... though, I wish it did. Such that, if you lost 12v power, and still had 120v power, the fridge would just continue 'running' since it was already 'ON'.

[RandK-M]

I have the same type of fridge and it won't work without 12v so no limp mode that I know of. I found that out 2 years ago when the camper was home in it's parking spot and my converter was going bad. The fridge was full of food and I didn't feel like emptying it while I waited for Amazon to deliver the new converter, so I temporarily wired in a 12v transformer by plugging it into the outlet behind the outside fridge access panel and splicing it in.

The above posts are correct as far as operation, it's either "Auto" which switches to gas when we unplug to get on the road, or forced into gas mode with the gas button. There is no forced AC mode except that as long as you have 120v AC, auto it's basically the same as being forced to 120v AC unless you loose power.

As a side note, I think maybe one of the reasons for the gas only mode is some people say the fridge cools better in hot weather on gas and prefer it when it's really hot out. I haven't verified that myself, but I've seen people mention the better cooling here on this forum.

Ray