Looking for Dometic DMR702 service manual

[MalibuDave42]

I have been having a lot of trouble with my fridge. The pattern seems ambient temperature related. During the cool nights in the CO mountains off the grid, the unit would not run until about 10am. This past week it snowed about 10" and stayed near or below freezing for several days. It would not ignite these cold days. Now back in the warmth, I see the igniter wire is pretty crispy where it enters the ceramic piece of the igniter. Not sure the will solve the problem, but time to replace regardless.

Not sure this matters.. furnace worked fine, stove, hot water heater -- all good. End of the propane line is the fridge. There was also about 1/8" of frost below the propane level in the tank I was using at the time.

Two questions for the group:
1. Where can I find a service manual to ensure I get the right part(s) when needed?
2. Any thoughts on my sporadic fridge?

Thanks
Dave

[sdtravis]

Dave, I solved my issue. Not sure if you have the same problem or not but wanted to post back here in case it helps.

After replacing the Thermofuse, eyebrow board, main board and electrode/ignitor, the problem still wasn't fixed. My attention turned to the valve solenoid next. The service manual states "The proper reading would be 49 ohms with tolerance range of ten
percent. Failure of the solenoid is very unlikely." Mine measured 44.6 consistently but given there's really not much left to try to replace I went ahead and replaced the entire valve assembly, inclusive of a new valve solenoid. Good news, problem solved, fridge stays on all night and I can now move on with my life with a functioning fridge. And now I have a box full of replacement parts I can use in the event the fridge starts acting up. Good luck with your issue, maybe this will be helpful.

[MalibuDave42]

sdtravis - Love your idea of a camera..

I read your old post. IMO, it's your regulator(s). This is a cheap fix. At minimum, a little money well spent for a far better, longer lasting product. At best, it cures your situation. (My trusted propane guy is on call for several local RV dealers.. he's says he gets many calls for brand new rigs -- bad regulators)

It also could be the igniter throwing an error. Replacing it is cheap and easy.

Also note: I see that Old_Biscuit replied to your old post.. take his word as gospel. He knows his stuff.

[sdtravis]

An update that adds to some of the mystery. I placed several cameras to get a better view of what happens when the fridge shuts down in the middle of the night and have a few interesting findings.

From the camera I put inside the exterior compartment, the fridge is running perfectly with plenty of flame then a loud click is heard (solenoid valve shutting) and the flame shuts down. There is NO attempt to relight the flame.

Two seconds later, the fridge starts displaying the error lights on the front panel.

If I close the valve on the propane or blow out the flame, the fridge automatically goes through 3 attempts at relight. In this instance the fridge is shutting itself down and not relighting which means its not likely to be an LP supply issue.

[sdtravis]

MalibuDave42 wrote:
I'm not 100% sure I have solved my ambient temperature problem. But, I do feel I am gaining ground on it. Since I started this thread, I have learned\done this:

1. My electrode was bad. I replaced it.
2. Frost on my tank is two fold
A. If the ambient temperature is below ~35, propane can't vaporize quickly enough to provide gas for appliances to work correctly. In cold weather, never let your tank(s) get below 1/2.
B. Regulators on RVs (as with many things) are the cheapest the RV vendor could find. In other words, they go bad pretty quickly.
In my case, cold weather, bad\inefficient regulators - I replaced both tank regulators and the switch between the tanks with higher quality and increased flow rate rating.
3. In cold weather, the refrigerant can freeze. In summer, the refrigerant can't release the heat it removed from the fridge efficiently. The heat can't be released from the coils since the fridge is "inside of a low air circulation box" (aka built into the side of the camper)
A. For summer - increase air circulation by adding temperature controlled fans to get the hot air out. I added two low amperage fans: 1 to suck in the bottom vent; Another to blow air out at the top vent.
B. For winter - reduce air circulation (never remove all circulation). I added a shaped foam rubber "stopper" for the lowest louvre of the lower vent door. If the temp is going low, I push the stopper into the lourve to reduce air flow.
4. The inside-of-the-fridge temperature sensor (thermistor) can go bad. I replaced it with a aftermarket variable thermistor.

I hope this information helps you. As I mentioned, I am not 100% sure I've corrected the problem - time will tell. I sure know a lot more about RV fridges now 🙂

I'm with you about knowing a lot more about these refrigerators than I bargained for. My unit DMR702 unit is brand spanking new and I can't figure this out. I'm out here in san diego with 43 degree night time weather and this refer is still shutting down in the middle of the night (see my original https://www.rv.net/forum/index.cfm/fuseaction/thread/tid/30185661/srt/pa/pging/1/page/1.cfmpost here).

As other posts have reminded me, this version of the Dometic fridge was fully outsourced and is known for quirky issues. I'd be curious to find out if you solved the issue on your end.

[dougrainer]

MalibuDave42 wrote:
I'm not 100% sure I have solved my ambient temperature problem. But, I do feel I am gaining ground on it. Since I started this thread, I have learned\done this:

1. My electrode was bad. I replaced it.
2. Frost on my tank is two fold
A. If the ambient temperature is below ~35, propane can't vaporize quickly enough to provide gas for appliances to work correctly. In cold weather, never let your tank(s) get below 1/2.
B. Regulators on RVs (as with many things) are the cheapest the RV vendor could find. In other words, they go bad pretty quickly.
In my case, cold weather, bad\inefficient regulators - I replaced both tank regulators and the switch between the tanks with higher quality and increased flow rate rating.
3. In cold weather, the refrigerant can freeze. In summer, the refrigerant can't release the heat it removed from the fridge efficiently. The heat can't be released from the coils since the fridge is "inside of a low air circulation box" (aka built into the side of the camper)
A. For summer - increase air circulation by adding temperature controlled fans to get the hot air out. I added two low amperage fans: 1 to suck in the bottom vent; Another to blow air out at the top vent.
B. For winter - reduce air circulation (never remove all circulation). I added a shaped foam rubber "stopper" for the lowest louvre of the lower vent door. If the temp is going low, I push the stopper into the lourve to reduce air flow.
4. The inside-of-the-fridge temperature sensor (thermistor) can go bad. I replaced it with a aftermarket variable thermistor.

I hope this information helps you. As I mentioned, I am not 100% sure I've corrected the problem - time will tell. I sure know a lot more about RV fridges now 🙂

OK lets take some misinformation first.
1. LP will vaporize down to -42 degrees. YES, a LOW LP fluid level will hamper vaporization, so YES, keep them full in cold weather
2. DO NOT restrict the air flow in freezing temps. Just add a 60 watt light bulb to the rear outside area of the refer
3. BOTH tank regulators????????????????????? I have NEVER seen a RV LP system with 2 LP regulators. Never in 41 years as a Tech. They have 1 regulator with a dual Auto switchover. Now, some 5th wheels have dual/triple tanks, with 2 tanks on 1 side and the 2nd or third on the opposite side. The hose between those types have a HI PRESSURE regulator to prevent a BAD accident if that hose springs a leak and would spew hi pressure/volume of LP. That hi pressure reg reduces the LP pressure from the tank to the other side. Usually the PSI (NOT the WC LP RV working pressure) is around 150 PSI out of a non regulated LP tank. This Reg drops it to about 30 PSI.
4. While they do use the Cheapest LP regulators, the main enemy of any regulator is, liquid LP. Liquid LP can be easily introduced if the LP cylinder is somehow overfilled. The auto shut offs do not always stop extra liquid when filling. Having a full cylinder whether on DOT tanks or ASME motorhome tanks, can allow the Liquid to slosh in transit and allow liquid to get into the regulator and either causing it to leak of cause pressure problems.
5. It appears that you had multiple problems and you slogged thru and fixed the various problems. Doug

[MalibuDave42]

I'm not 100% sure I have solved my ambient temperature problem. But, I do feel I am gaining ground on it. Since I started this thread, I have learned\done this:

1. My electrode was bad. I replaced it.
2. Frost on my tank is two fold
A. If the ambient temperature is below ~35, propane can't vaporize quickly enough to provide gas for appliances to work correctly. In cold weather, never let your tank(s) get below 1/2.
B. Regulators on RVs (as with many things) are the cheapest the RV vendor could find. In other words, they go bad pretty quickly.
In my case, cold weather, bad\inefficient regulators - I replaced both tank regulators and the switch between the tanks with higher quality and increased flow rate rating.
3. In cold weather, the refrigerant can freeze. In summer, the refrigerant can't release the heat it removed from the fridge efficiently. The heat can't be released from the coils since the fridge is "inside of a low air circulation box" (aka built into the side of the camper)
A. For summer - increase air circulation by adding temperature controlled fans to get the hot air out. I added two low amperage fans: 1 to suck in the bottom vent; Another to blow air out at the top vent.
B. For winter - reduce air circulation (never remove all circulation). I added a shaped foam rubber "stopper" for the lowest louvre of the lower vent door. If the temp is going low, I push the stopper into the lourve to reduce air flow.
4. The inside-of-the-fridge temperature sensor (thermistor) can go bad. I replaced it with a aftermarket variable thermistor.

I hope this information helps you. As I mentioned, I am not 100% sure I've corrected the problem - time will tell. I sure know a lot more about RV fridges now 🙂

[sdtravis]

Dave I’m having the same ambient temperature issue with my DMR702 fridge. Curious if you solved the problem with the new electrode.

[MalibuDave42]

Talked with Dometic this morning. They confirmed the igniter part number for the DMR702 is the same as Old-Biscuit stated: Dometic 2932781012.

The rep took the time to screen shot the exploded parts view including part numbers and emailed them to me. I am happy to share, but don't know how to post it here.

Thanks for all of the insights and help!!
Dave

[Old-Biscuit]

You posted
"It would not ignite these cold days. Now back in the warmth, I see the igniter wire is pretty crispy where it enters the ceramic piece of the igniter."

Sure seems like electrode issue

YES electrode provides dual function
Ignition and flame proving boa Flame Rectification ( electrical process that causes a low level DC current to be conducted from the flame rod through the flame, and back to ground---circuit board senses this dc current)
Your model doesn't use a thermocouple


Maybe DOUG can post up a part number for your spark electrode

[MalibuDave42]

Reaching for straws... wires don't work as well when cold, so trying to connect the dots.

Thanks for the insights -- unrelated, got it. Thoughts on what it could be?

Dave

[dougrainer]

MalibuDave42 wrote:
I've seen that part number around the web. The part sure looks the same. But as you point out, call to Dometic to confirm would save me aggravation in the long run. Wierd business model.. keep the part list secret to reduce customer satisfaction 🙂

Interesting point on the Spark Electrode. You are saying it's two-in-one sparker AND thermocouple. Correct?

Do you feel this could be related to my apparent ambient temperature issue?

AS long as the refer stays lit and does NOT throw a red light or error code, the Ignitor will have NOTHING to do with cooling problems. Kind of like saying, I have a slightly burnt Spark Plug wire and my Dash AC does not cool correctly. NOT related. Doug

[MalibuDave42]

I've seen that part number around the web. The part sure looks the same. But as you point out, call to Dometic to confirm would save me aggravation in the long run. Wierd business model.. keep the part list secret to reduce customer satisfaction 🙂

Interesting point on the Spark Electrode. You are saying it's two-in-one sparker AND thermocouple. Correct?

Do you feel this could be related to my apparent ambient temperature issue?

[Old-Biscuit]

Installation/Operation Manual
Clearances for installation/Component ID/Wiring Diagram etc
DMR702/DMC702 Manual

Parts.........
NO PARTS LIST Available
Even Dometic doesn't list any Renaissance Series Parts (DMR702/DMC702)
Renaissance Parts

Looks like a Call to Dometic is in order.....
Have Product Number and/or SKU Number available (on data sticker


As for that Spark Electrode
That wire MUST be intact
It carries the High DC Voltage that ignites the gas BUT it also is part of the flame proving circuit (milliamp signal that circuit board senses ---- no signal/DC is shutoff to gas valve)

Dometic 2932781012 (Part number for spark electrode used on NUMEROUS Dometic Fridge Models....17" Lead)

[MalibuDave42]

Nice doc to have on hand. A few parts numbers, but none for the igniter. Thanks for passing along, though.

Dave