Norcold 1210 doubledoor not cooling.

[CJW8]

New RV. I've been using it for a couple of months and all has been well even when ambient temps were into the 100's. It is installed in a slide.

I woke up this AM and opened the fridge door to get something and noticed it wasn't as cold as it should be. I checked the freezer and things were thawing. I was running it on electric and it has been freezing outside at night and 50's F in the day. I put a digital temp gauge in the freezer and after an hour it read 38F. Ice cubes were mushy and there was 1/4 to 1/2" ice on the back wall.

I defrosted it and dried it out. I switched it to gas. In 8 hours it is only down to 37.3 and holding.

I read that absorption (sp) refers were less efficient at freezing ambient temperatures so I blocked off the lower vents and mounted a 60 watt bulb in the back compartment. After a couple of hours running this was it is still at 37.3 in the freezer.

I am running it on 9 which is the coldest setting. Any ideas?

[fourthclassC]

I had a situation with a happy ending - so far. Norcold quit on Fl trip. Older unit-no warrentee. Successfully re-set control board and its been working great ever since. But I would like to upgrade to an improved control board like I did on my old dometic. Does RV mobile still exist? If not does any one know if those type of improved boards are still available. Would rather replace with one of them than a standard Norcold replacement.

Thank you

[CJW8]

UPDATE:
The technician couldn't get back to this until after the New Year. His preliminary conclusion before Christmas was that the cooling unit was bad but Norcold required him to follow an elaborate test procedure requiring a few days to complete. He had to do something each day and check it the next day to see the results. After the test, he determined it was a bad control board and he replaced it. It has now ran for several days at 4 deg F in the freezer and 33 deg F in the refer. Job complete. The board cost was about $200 for a Norcold brand board and I didn't even ask what the labor cost was but I'm sure it wasn't cheap. Fortunately, it is covered under warranty.

[CJW8]

Nothing to loose, I will shut it down over night and restart in the AM.

[Old-Biscuit]

Cooling Unit Blockage
When a cooling unit malfunctions due to a blockage, the boiler section may be too hot to touch and the absorber will be relatively cool. Any blockage reduces the free flow of the solutions and will inhibit or completely prevent proper operation.

Leaking Cooling Unit
If the boiler is warm and the absorber is hot this indicates that a leak has developed and the hydrogen gas has escaped. The liquid ammonia does not change to a vapor without the hydrogen gas atmosphere and circulates as a liquid.


HOT absorber tank......hydrogen gas has leaked out. You have a crack somewhere

[Chris_Bryant]

Do try shutting it off for a few hours and restarting it. They can get "vapor locked", and letting the pressure equalize will remedy that.

[CJW8]

In the refer I have a classical red liquid filled thermometer for refrigerators. It is hanging in the muddle of the middle shelf. In the freezer I have a digital thermometer that has a thermocouple. (I don't have to open the door to check it) I have verified both in ambient and in ice water. I am an Instrument Technician/SCADA analyst by trade, I know my instruments work. In the last 2 days the freezer has cooled to 28 F and the refer is holding at 45 F.

I see no sighs if the dreaded yellow deposits. I am trying to make an appointment for service now. I just spoke to the local technician. He said if the accumulator tank (my term cuz that is what it looks like) is quite hot, which it is, it is back boiling and likely needs a new cooling unit. Said I could try and jar whatever is plugged in the cooling system loose by going down a bumpy road but it is unlikely to fix it.

[dougrainer]

CJW8 wrote:
It is not in BOS mode. Rear cooling fans are running. I went through the diagnostics screens (thanks for the link to the service manual Old-Biscuit!) and nothing jumped out at me. There is nothing more I can check and will have to get it serviced. Today freezer is 35 F and ref. is 45 F.

The only thing I haven't tried is shutting it off for 24 hours and letting it settle. Would there be any benefit in this?

These temps do not make sense. IF you are getting 45 in the lower refer section(that means the evap fins are 35 degrees), then you should be getting lower than 35 in the freezer. HOW are you measuring the temps? If the temps are correct, then the cooling unit is BAD. Look for the dreaded Yellow powder/stain at the lower burner area, especially behind the insulation foil pack above the burner. BUT, if the cooling unit is bad/leaker, the Recall box should have tripped. Also, IF the temps are correct a NO CO code should also have been thrown. Doug
PS, you CANNOT use a Thermal Thermometer as a temp measuring device on a refer.

[CJW8]

What if I need that break? LOL
I am doing the testing now.

[Old-Biscuit]

Only benefit from shutting it down would be a 'break from messing with it'


Did you go thru the 'cooling unit testing' pg. 65,66,67?

Cooling unit clogged........warranty>>>

[CJW8]

It is not in BOS mode. Rear cooling fans are running. I went through the diagnostics screens (thanks for the link to the service manual Old-Biscuit!) and nothing jumped out at me. There is nothing more I can check and will have to get it serviced. Today freezer is 35 F and ref. is 45 F.

The only thing I haven't tried is shutting it off for 24 hours and letting it settle. Would there be any benefit in this?

[dougrainer]

CJW8 wrote:
according to THIS I reset the control board. Will see what happens. Results are so slow when working on these things.

This is the problem with these type forums(bad info). A RESET is ONLY for complete lock out of the refer, NO functions at all. So, your reset is useless. DO NOT block off the air flow. ANOTHER problem with these type forums. NEVER block off the air flow. You can install that light bulb. BUT, this procedure is for temps consistently BELOW 25 degrees. So, I would verify the rear cooling fans are running. Also, the temp of the freezer should be BELOW 10 degrees. If NOT, you have a major refer problem. The fact it is in a slide points to rear air flow(rear cooling fans inop). Doug

[CJW8]

according to THIS I reset the control board. Will see what happens. Results are so slow when working on these things.

[Old-Biscuit]

You have 2 'moisture reduction heaters'
One is molded in the center divider section and the other is that flapper seal
Powered on anytime fridge is on. Flapper is turned on when left door is closed.
Not your lack of cooling issue


Ice crystals forming on freezer??
When you push the SET TEMP button does the number flash or remain steady?
Flashing...operating on 'BOS' backup operating system due to temp sensing failure. Duty cycle of heat source then has to be controlled via temp set point.

But it is sounding more and more like cooling unit blockage.
Check out this service manual.....LINK
Go to page 65 and then do cooling unit test following page 66 & 67

[CJW8]

Old-Biscuit wrote:

Air flow is needed (Draft) to remove heat from cooling unit.
Blocking off a couple of vents and using a 60W bulb helps when temps are below freezing....but not completely blocked off.

I did this this afternoon. Blocked 2 of 3 slots in lower vent cover and I installed a 60 watt bulb.

Observation- I can see ice crystals starting on back wall of left freezer compartment.

The center sealing strip between the double refer doors seems warm to the touch. I don't know why there would be a heater strip in this area. OK, I see 3 contact points on the door that make when the door is closed. I put tape over them to disable them for now.