Dometic 2-mode Fridge operation: Had to read the manual

[Underthedog]

Went out to turn on the fridge for vacation cool-down. It is the 2 mode (AC/LP) model. I ass/u/med it would run on AC and left the LP off. When I turned it on it tried to run in LP mode. So I dug out the manual . Turns out you can set it to AU (automatic) or LP (LP). LP forces it to run on propane. AU lets the fridge decide. There is no 'use AC' mode. The manual gives no indication on the AC/LP selection process. Perhaps it is more efficient on LP during a warm start. The trailer is plugged in to a 15AMP house circuit. Perhaps that affected the selection process somehow.

It will be interesting to see what it does during our first long trip.

And something to be aware of if your fridge doesn't seem to be working properly (or you are using more propane than you expected).

[Flybob]

It operates that way by design. The auto mode is designed to be used when connected to shore power. If you are away and the power goes out then the fridge will automatically switch to propane until the power returns. Note you need to have the propane on. The propane only mode can be used when you have limited power capacity on shore power and want to reduce current draw to allow another appliance ( ie AC) to use power. Or if you are trying to recharge batteries while boon docking using a small generator.

[JustDaisy]

Interesting information that gives me pause. We are at home and plugged to the house. When we do this we typically turn our propane off. That said your description tells me this could cause a problem for our fridge if the power goes out. Can we do harm to the fridge if the propane is off and it goes looking for propane because the power is out?

[CedarCreekWoody]

Originally Posted by JustDaisy

Interesting information that gives me pause. We are at home and plugged to the house. When we do this we typically turn our propane off. That said your description tells me this could cause a problem for our fridge if the power goes out. Can we do harm to the fridge if the propane is off and it goes looking for propane because the power is out?

It won't harm the fridge. It will just shut off the fridge and let it warm up inside, possibly spoiling food.
We always plug in on TT the day before a trip to pre-cooked the fridge. I put it on auto and open the valve on the propane tank as a backup in case of power outage. When we travel I unplug from power and assure it us running on propane. Some tow with propane on, others prefer it off. I keep it on.

[bradybr]

My fridge has two buttons, one for auto, and one for gas. When I push the auto button in, leaving the gas button out, and have shore power, I don't get cooling. Only when the auto button and the gas are both pushed in does the fridge begin to cool. So, to me, it appears that both auto and gas have to be on for cooling of the fridge. When I don't have shore power, the auto is using the batteries. Does that make sense and is it correct?

Thanks for your response.

Bob

[WestCoastRV'er]

Originally Posted by bradybr

My fridge has two buttons, one for auto, and one for gas. When I push the auto button in, leaving the gas button out, and have shore power, I don't get cooling. Only when the auto button and the gas are both pushed in does the fridge begin to cool. So, to me, it appears that both auto and gas have to be on for cooling of the fridge. When I don't have shore power, the auto is using the batteries. Does that make sense and is it correct?

Thanks for your response.

Bob

Auto Mode:
Runs on AC first and then uses Propane if AC is not available.

Gas Mode:
Runs on Propane only

If your fridge doesn't cool on AC then you may need to replace the AC heater element for the fridge. I'd check the Power Panel and outlet to ensure you have power. Lots of videos on Youtube on replacing.

If your fridge doesn't cool on Propane it could be rust in the burner or low Propane pressure. I just had to replace my regulator because of low pressure and it had about a tablespoon of rust particles in the burner tube. On propane, it would barely keep it cold. Now it works great. Our stove burners are working much better now too with the added pressure. Videos on Youtube can walk you thru how to clean burner tube.

Just a couple of things to look for when your fridge doesn't cool anymore.

[CedarCreekWoody]

When running on propane it uses 12 volt battery power to ignite the flame as the unit cycles on and off. It can also power the heating element.

[Underthedog]

The dang ground fault had tripped on that circuit.

<sigh>