Dometic Fridge Replacement with Residential Whirlpool

[hilgert]

Thought I'd post my experience replacing a Dometic refrigerator with a residential Whirlpool in our 2017 Sunseeker motorhome.

There were a few reasons we wanted to do this:

• The current Dometic 2652 was small...fitting more than one gallon of milk was difficult, so a longer stay involved multiple trips to the store. It’s less of an issue of the trip to the store as it is an issue of *not having* what we needed when we wanted it.
• We wanted more shelf space so that we did not have to Tetris stack stuff…the wife and I got pretty good and cramming stuff in, but it was always a crap shoot of what would happen when opening the door after traveling.
• The Dometic just did not get super cold. While ice cream did not melt, it was always a bit soft, etc. This is a problem with all of the RV ridges from what I’ve seen.
• We hated having to defrost...so any new unit would have to be frost free.

The Dometic was shorter than the Whirlpool WRT111SFDB that we replaced it with, so this involved some reconstruction in the motorhome. Essentially, I had to remove a drawer below the Dometic to make room, which was fine because at the same time I removed the gas oven (which we never used...the Sunkeer came with a convection oven). I disconnected the oven from the cooktop (so I still have the oven dial on the cooktop...no biggie to us), and replaced it with a drawer that I had my dealer purchase from Forest River. So, in the end, I actually *gained* space since the drawer was bigger, and the Whirlpool was bigger.

Pix and description will start from where I started the rebuild (the removal was just the usual ripping stuff out, etc.).

[hilgert]

This is the Whirlpool WRT111SFDB refrigerator that I put in. The B is for black…there is M for stainless and W for white (not sure who would want white)…our appliances are black so that’s what I went with (plus I can repaint black if it gets scratched). I ordered it from Home Depot (Best Buy and Lowe’s sell them as well, but I happened to have a few Home Depot gift cards), and had it delivered to my garage. Once delivered the rip-out process began (I like to make sure I have *all* parts necessary before I start a project). $400-425 seems to be the going rate with free delivery.

[hilgert]

Since the motorhome engine alternator will keep the house batteries topped off when driving, I wanted to have an inverter to power the refrigerator when no plugged into shore power (or when not running the generator).

As an electrical engineer I am aware of the damage a MSW (modified sine wave) inverter could do to electronics, including refrigerator compressor motors. Therefore, I knew I needed an inverter that meet several criteria:

• Must be PSW (pure sign wave).
• Must have auto transfer capability (xfer back/forth from battery/120V).
• Must have a mechanical power switch…an electronic switch would need to be “restarted” whenever 12V power is lost.
• Wanted a hardwired unit (for the 120V circuits).
• Must be industrial grade…when powering a fridge, don’t screw around.

After considerable research I came upon this unit [below] that met all of the above requirements. I called the distributor and had a long talk…they were able to answer all questions to my satisfaction (and I’m quite picky). Turns out (if they can be believed) the they have their own manufacturing plant in China, and make units under 3 brand names. Who knows if it’s true or not, but the person I talked to answered every technical question I had, and was able to quickly send me documentation on the unit in advance of me purchasing it on Amazon.

The unit is larger than you would expect…this is no toy inverter. I popped the back [mounting] panel off, and the construction on the inside is certainly industrial grade. Lots of room for air movement, and the large case will provide surface area for cooling. However, I don’t expect it to get too hot as the refrigerator seems to sip power…it was hard to get a good reading from my analog current clamp. I did run it overnight on the inverter and when running it never got even warm.

The unit has no 120V plugs, just terminal blocks for hard wiring (again, this is no toy inverter…it’s meant for permanent installation). I hardwired the 120V output to one end of an extension cord the I cut, which goes to the load (fridge in this case). I hardwired the 120V input to the other end of the same cut extension cord, which I plugged into the house fridge outlet. At some point I may hardwire both to the fridge breaker and a receptacle, but this was a quick and easy approach to get it running. From the design of the platform and bracing it’s easy for me to pull the fridge 80% of the way out to rework the wiring (more on this later).

When there is no 120V shore power the inverter powers from the battery. When connected to shore power, after about 4 seconds, the inverter switches seamlessly over to shore power via a pass-through transfer. I hooked up an old laptop with with it’s battery removed and there was no loss of power…I did this about 10 times to be sure…the transfer back/forth is seamless.

Power Bright APT1200-12 Pure Sine Power Inverter with Automatic transfer 1200 Watt continuous

[hilgert]

Instead of using a platform I decided to use 2x4’s since the unit would only sit on the sides and not the middle. Also, this created a very nice place for me to put the inverter…I notched out places for the inverter mounting bracket and installed it upside down. This also allows me to slide the refrigerator out (more on this later) and get into the furnace/wiring area. The front of the inverter (with indicator lights and power switch) is accessible form the inside furnace access panel.

[hilgert]

I replaced the panel covering the house wiring on the side.

On top I put two 2x4’s on the left/right, the bottom of which are 1/16” (0.0625 inches) higher than the top of the fridge. They run almost the entire front/back length, which allows me to pull the fridge out about 80% of it’s depth if necessary without tipping (for example, to pull the inverter or mess with other wiring). This also helps stabilize the fridge front/back (no tipping) when in motion. Left/right tipping is solved by the cabinet sides (which I adjusted accordingly).

At the back of the top there is a 1x3 the just hits the back of the top of the fridge, which keeps it from sliding further back.

So the fridge cannot go up or tip (top side2x4’s), can’t go down (platform 2x4’s), can’t go back (top back 1x3), cannot go side-to-side (sides of cabinet) which leaves forward (covered in a few posts).

As a residential fridge generates WAY less heat than the Dometic, I blocked off the top roof vent from the inside (required for the Dometic due to the heat) with some plywood (this can be seen in the second image below), and will eventually pop the roof vent off and fill it with some insulation of some kind. I like to do small projects when we are camping, so this is a good 30 minute project during our next camping trip.

[hilgert]

I did not want wheels…wheels are bad in a moving vehicle. Also, wheels and the two leveling feet are just for point sources for the weight. Instead I removed the wheels, and removed the posts for the feet (one of which needed to use a Dremel to cut off).

Unfortunately (I was an idiot), I did not take a picture of the next step, which was to attach 1x2’s along each side of the fridge. I used 3M VHB tape (once this stuff sets for a day to two it’s hard as heck to remove).

The 1x2’s perform three jobs:

• They distribute the weight.
• They keep the fridge from “free wheeling” (no wheels).
• They make the fridge site perfectly flat…not need to adjust when installing.

[hilgert]

Once the fridge is in-place I needed to prevent it from sliding out (all other potentialities were covered above by the framing/cabinet as in the prior post). I installed two hooks from Lowe’s in the back, screwed into the 2x4 platform. I consider this much safer than clips on the front screwed into the lightweight cabinet work. Plus, with the top 2x4’s preventing tipping, there is relatively little force on the hooks/screws.

[hilgert]

Since this is a residential fridge, it generates WAY less heat than the Dometic. Therefore, I’ve allowed for internally cooling of the coils by allowing air from below (through the furnace air opening as well as the open platform, so heat will come out of the top. Note the grill above the fridge.

Essentially, this is the same as the fridge inside your house…it does not generate enough heat to matter inside, and they are WAY more efficient (this unit burns about 1kWh per pay, so that’s equivalent to a 100W bulb during for 1 hours…nothing. Note that we do keep our motorhome plugged in when in storage, so heat is not really an issue inside.

This weekend I will insulate/seal the exterior access panel to prevent outside air from coming in.

[hilgert]

Traveling with a residential fridge has an interesting challenge that RV fridges solve…and that is to keep the doors from swinging open when driving down the road. I did not want clips that had to be pressed each time to open a door, BUT I did want something that would positively lock the door when in motion. This could not be complicated, and must be easily visible for pre-departure checks (and yet unobtrusive).

I ended up with window latches from Lowe’s, and I used some short clips that I screwed into the side of the fridge (had to bend the ends). Less than $10 total in parts, and it matches nicely. Very unobtrusive, and easy to engage. Also very easy to tell when they are latched or not.

[hilgert]

Some as-installed pictures. Note that I do have to clean up the sides of the cabinet (had to enlarge it just a bit…where the freezer and refrigerator sections join the sides are a bit wider than the rest of the fridge…not sure why they do that), and some other general cleanup/trim work.

The doors stick out a few inches further than the Dometic, but not so much that you notice. The inside is far more spacious than the Dometic, and we can hold whatever we want for a week long trip. Where the Dometic took HOURS AND HOURS to cool down after defrosting, this thing froze a load of ice *from startup* in just a couple of hours.

[CountryFit]

nice job!
i did mine a month ago.

[whiteva]

Excellent job and write up.

[scooterbob]

nice write up and description, I plan on the upgrade in the near future.

[hilgert]

Originally Posted by scooterbob

nice write up and description, I plan on the upgrade in the near future.

When you do the upgrade, I *highly* recommend the inverter I mentioned above. It's big, but it's a real PSW inverter with full auto transfer, and no electronic momentary on/off switch...it's got a on/off rocker switch. Most of the other's I've seen have an electronic momentary on/off switch, so you'd have to manually press it if you lost 12V power at any point.

Note that on this unit (my unit), if I have the switch off, it defaults to pass-through of the 120V. So if the inverter failed (for most reasons other than a total meltdown) I always have my onboard generator for driving down the road (not that I'd need it...I bet this fridge will keep cold for whole day of travelling with no power).