Dometic Servel RGE400 fridge too cold

[GuyCanRV]

Well it's been almost a year now since I revived my RGE400 fridge for a second time.

As I mentioned in my last post about the fridge when I put it together the control
rods were messed up and I didn't want to spend too much time with them.
I was also missing some end caps etc.

So basically I was operating the temperature control blind.
After getting the fridge to work (electricity only) it was far too cold.
So I removed all the food and laid the fridge down to gain access to the control rods
at the back.
I tried turning the rod once again to a lower setting (blind, once again).

Since then I haven't touched the temp control, but the adjustment didn't make a difference.
The fridge is still way too cold. A lot of the food actually freezes!

I'm open to suggestions.
I think the thermostat is probably malfunctioning.
Is there a way to test it/fix it?
There is something else I thought of.
I recall reading somewhere that the thermostat coil that feeds into the fridge from the fins,
can be adjusted. Pulled inside the fridge more or less.
I remember reading that this can be used to adjust the fridge temperature as well.

Again any guidance would be appreciated.

[StirCrazy]

is it way to cold in one spot, or is stuff freezing throughout the whole fridge, it is is only a spot, then a small battery powered fan could help by moving the air around and evening out the temp? 

HERE  is a video on adjusting temp.  if you have tried everything there then we can start loking for an issue.  but if you have moved the clip up and down on the fin and it made no difference it could be the thermal couple that attaches to the fin that actualy gets moved up and down.  

[GuyCanRV · Accepted solution]

Thanks for helping out StirCrazy!

I finally fixed the freezing problem.  🙂

More than 10 years ago when I was replacing the original bad thermostat I had problems connecting the
temperature control rod to the thermostat. I gave up on it and just set the temperature blindly to something that seemed to be around 4/10 on the thermostat.
I didn't really care about not being able to adjust the temp with the control rod because in the previous 10+ years I never touched the temp.
When I had my cooling unit in for repairs about a year ago I must have adjusted the thermostat a bit.
Because for the past year I had this freezing problem.

Well a week or so ago after the new thermostat still hadn't solved the problem I decided to have a go again attaching the control rod. I found the plastic piece that was critical to connecting the rod to the thermostat. I did the whole operation with the fridge standing upright, which was quite the challenge!

Once everything was connected properly I set the thermostat to around 2-3.
It seemed to have fixed the problem but I didn't want to celebrate too soon. I waited a week or so before I was confident there was no more freezing. The food was still quite cold so that's why I wasn't sure at first.
So now that everything is working properly again I really don't know if the new thermostat was necessary or not. It's quite possible that had I done the same operation with my existing thermostat it also would have fixed the problem.
I am keeping the old one just in case and am thinking of actually buying another new one as a backup.
I was surprised to be able to buy this new one. But it said it works on many Dometic models so it wasn't my model specifically.

In the 26 years that I have been using my fridge (which I love) I have learned there are only two critical components; the cooling unit and the thermostat.
Do you think I should buy another backup thermostat while I still can?

[StirCrazy]

I don't know.  a thermostat is a pretty robust unit.  and usaly you could find a used one pretty easy, but if they are cheep why not.  

[GuyCanRV]

Well they aren't exactly cheap at $250 CAD.
But I would gladly buy a backup to keep my fridge going in 'x' number of years should it ever fail.
Maybe you could help me out with one other critical component I forgot to mention.
It's the rubber seals that hold the door shut.
They haven't been holding the door as firmly closed as I 'd like for quite some time.
I don't know if any air is seeping in or not.
I looked into replacement rubber seals quite a while ago but couldn't find anything.
Maybe you could suggest something for this?

[StirCrazy]

https://pdxrvwholesale.com/products/dometic-refrigerator-door-gasket-kit-3108708375 

[GuyCanRV]

Thanks very much. The list of models on the first page mentions mine (RGE400) so it should work with mine too. But even after having read the instructions and looking at mine, it isn't clear where/how I should be making the cuts. I think I'll try to contact the seller for more info on this.

[GuyCanRV]

I installed the new thermostat a couple of days ago but the fridge is still way too cold!
Just like before. The food is freezing!
I have the thermostat set at 4. It goes from 1 - 7.
Any ideas what I should do now?

[GuyCanRV]

Still don't know what my next move should be.
The thermocouple is only needed if gas is being used right?
The thermostat has two holes, one on each side.
I stuffed the pipe into the right side.
I cut off the left side pipe many years ago when I was having
trouble removing the thermostat. It goes to the gas burner.
I had it left open like that for more than 10 years with no issues.
The food was not freezing like now.

[joebedford]

Have you moved the temperature sensor on the grid fins?

You can unplug it and test the resistance.

[GuyCanRV]

Thanks for helping out Joe.
I don't know if I should lengthen the sensor to make the fridge warmer or colder?
Did you mean unplug the fridge?
How would I test the resistance and what reading should I be looking for?

[joebedford]

AI mean unplug the sensor and check the sensor's resistance.. it's possible it's not working and an ohmmeter will tell you.

[GuyCanRV]

Thanks Joe.
Well I ordered a new thermostat and it arrived today.
I have a couple of questions about it.
There are two pieces of black tape on either side of the unit that seem to be covering something. What are they for? Should I leave them as is?
It came with two tiny rubber 'o rings'. What are they for? Where do they go?
Thanks.

[aftermath]

If the sensor is high up on the fin it will make the temperature in the fridge colder.  Move the sensor down and it should keep things "warmer".  Cold air pools down low so if you have the sensor down low, the cold air will get to it sooner causing the fridge to shut off.  Just the opposite if it is high in the cavity.  Takes longer for the cold air to pool around the sensor, hence it runs longer, hence colder temperatures in general.

[GuyCanRV]

Thanks for helping aftermath.
I tried moving the sensor down all the way to the bottom of the fin
but it didn't help. Fridge is still just as cold as before and the veggies
are freezing.
I think I'm running out of options now?