Newbie - can make the fridge or the furnace to work properly

[Achou]

Hi

I fell in love with a Trillium 4500 from 1978. (Almost) everything is from origin and it has been inspected by professionals who told me that everything was working.

However, after reading the manuals, I can seem to make them work!

The fridge is a Dometic RM 2309 gas electric. I can’t seem to make it cool under any gas or 110v. (I followed the basic directive of setting the desired mode and then the power at 25%).

For the furnace, same applies.

we must be doing something wrong.... any tips to help us solve this?

Thank you for your help!

[k corbin]

Sounds like the issue is at the propane tank end of things. My once upon a time computer teacher told me a valuable piece of advice for troubleshooting. Always check the physical connection first.

In this case...
do you have propane in the tank?
do you know how to open the valve?
has the air been purged from the line?

To purge the air people usually light a burner on the stove top and leave it lit for 10 minutes or so.

Remember all the basic lessons for using propane tanks and the control valves that are at the tank and for operating the various propane appliances in an RV can be found on youtube.

[Achou]

We did start with this. We have gas for the stove and the 110V works for lights and plugs. Any other suggestions?

[jcwill]

Originally Posted by Achou

We did start with this. We have gas for the stove and the 110V works for lights and plugs. Any other suggestions?

First of all, these refrigerators take a LOOONG time to cool. They are faster on propane but still not at all like a compressor type refrigerator/freezer. Inside the outside vent of the refrigerator is a round vertical tube. You will see where the flame vents around the tube. Look and see / feel if it lights up when you turn it on. If it does maybe you could wait 6 hours and see if it is getting cold. There is also an electric coil under the tube that heats up like a space heater. If you didn't get a flame you can feel the tube after the electric side is activated for a bit and see if it is getting hot. If it is then wait overnight to see if it gets cold in the freezer. If it doesn't get hot then it is either an electric connection that isn't starting the coil and/or the igniter or if the electric heating coil doesn't get warm on the tube it could also be a bad heating coil. If gas isn't heating it will either be a propane leak or blockage as stated earlier or a bad igniter.
If it does not work even when heating the tube then it is probably a leak of coolant (ammonia).
When you open the vent cabinet outside if you see corrosion in the space inside then the ammonia has probably vented and the refrigerator needs replacing.

[gordon2]

Originally Posted by Achou

We did start with this. We have gas for the stove and the 110V works for lights and plugs. Any other suggestions?

Either the equipment has a problem, or it is not being used correctly.

I'm glad you read the manuals and that makes improper operation less likely.

But 110 volts for lights and plugs is not 12 volts, and a furnace or fridge might require the low voltage (12 volt) supply. Many modern ones do. But I have no idea what is in a 1978 Trillium (others on this forum will). And I did not find a manual for a Dometic RM 2309.

A lot of people who have never used an absorption fridge before are not aware of the peculiarities of that type of fridge. There is so much info on that topic online I wont bother to try to echo it here.

But since you also have a problem with the furnace (which you were not specific about), my guess is an equipment issue that affects both. The fridge is more sensitive to improper gas pressure than the stove is, and I think the furnace might also. So based on very limited info, the suspect is the propane system since that is the primary common factor. But as I said, if they require 12 volts DC then that is another thing to check.

There are some service manuals online for RV furnaces and fridges and even if you can't find one for the exact model, maybe there is one that is close enough. They generally include a trouble-shooting flowchart, detailing the steps a service tech would take to find the problem.

But I keep going back in my mind to your comment:

Originally Posted by Achou

...it has been inspected by professionals who told me that everything was working....

So why not go back to the same professional(s) and ask them why it is not working? I wonder, was the propane system inspected by a professional who checked for proper pressure level under load, and using a manometer? And was the pressure checked at the appliance at the test port(s)? What about water or corrosion in the lines.. you are dealing with a very old camper - if the appliances are original then I would expect some issues, and they could well take some expert on-site evaluation.

[jcwill]

I agree with Gordon but since both 110 and propane didn't work I am inclined to think it is going to be unrelated to the furnace issue. It could be 2 unrelated problems. Since the 110 side of the refrigerator doesn't need propane at all it seems to me like the 12 volt controls inside the refrigerator are a pretty likely culprit. That is why I wanted you to observe the heating unit of the fridge and make sure it is doing some sort of heating on either 110 or gas. If neither does anything it will never cool down and it is likely in the 12 volt controls since both gas and 110 use those controls to know when to start and stop.

[gordon2]

Originally Posted by jcwill

I agree with Gordon but since both 110 and propane didn't work I am inclined to think it is going to be unrelated to the furnace issue. It could be 2 unrelated problems. Since the 110 side of the refrigerator doesn't need propane at all it seems to me like the 12 volt controls inside the refrigerator are a pretty likely culprit. That is why I wanted you to observe the heating unit of the fridge and make sure it is doing some sort of heating on either 110 or gas. If neither does anything it will never cool down and it is likely in the 12 volt controls since both gas and 110 use those controls to know when to start and stop.

Ahh.. good point, the 120 volts works in the camper, but the fridge does not work on 120.. I kinda missed that.

Part of this is very basic.. check the 120 supply for the fridge.. is it a standard outlet? Does it work.. plug in a light and see! Next you check the heating element in the fridge... but now its getting more technical so proceed as long as you are comfortable with it.

As for 12 volt controls at the fridge... I kinda doubt that a 2 (or is it 3) way fridge from the late 1970's requires 12 volts (for a control board, etc). Can anyone find a service manual for it?

I'm thinking its time for some updated appliances anyway.

[John in Michigan]

Hi Maggy,

I have a 1978 Trillium 4500 with original Dometic 36 TF fridge. It operates in either 110 VAC, 12 VDC or LP gas mode. There is no 12 vdc control.

For your camper, I would first try operating in 110 VAC mode. First verify that trailer is level. Then verify there is 110 VAC power at the outlet inside the refrigerator compartment (fridge should be plugged in). To do this, open the exterior lower vent, unplug the fridge and test the outlet with either a multi-meter or by plugging a simple appliance (radio, etc) into the outlet.

I generally set the thermostat to MAX, and then feel the cooling coil inside the freezer after 3 or 4 hours. At that time, there should be frost on the coil and it should be very cold.

EDIT: I find lighting the LP gas burner much more challenging. It requires pressing the ignition button while simultaneously pulling the primer knob (and holding for a minute or more).

-John

[Lisa in Michigan]

I would try the fridge on 110 first.

On our 40 year old fridge (Dometic RM36 RF) it is very hard to see that it is lit on propane from inside the trailer. There is a little tab inside our fridge in the front on the bottom by the other controls that glows a faint blue when the flame is lit. We have to close all the curtains and cup our hands around the indicator tab to see that the flame lit during the day.

[mbbear]

I guess that I spend too much time on FaceBook, but I sure wish that we had a like button for comments. You guys are so terrific, helpful, and generous with your time. I appreciate and salute you!

[Gilles]

Perhaps you can find your answer in this document that explains the operation of a refrigerator, or will provide you with another source of information ...

http://www.nationalserroscotty.org/r...ice-manual.pdf

Have a good day.

[Achou]

Thank you jcwill and gordon2. Your explanation really helped! We managed to make the fridge work under 110V and from the battery. (I am glad you were there because we were in the wild with little wifi connectivity and the place that evaluated the trailer was closed).

What we can confirm is that we needed to be much more patient that we were! The manual says that it will cool down within 30 minutes. This is incorrect; to jcwill's point, it took several hours.

I suspect this the issue with the gas is similar because I heard the distinctive click from the fridge under propane mode but we were too nervous with the gas and never gave it the chance to cool.

In regards to the furnace, it was never really used by the previous owner so it may take more than then suggested 10 seconds from the manual to fill the system back with gas. Someone even recommended holding the button for 60 seconds. but it has been soo warm outside these past weeks, we never had the courage to try it.

Thank you Gilles also for the documentation. We are reading it!

This is a new adventure for us but we love it.

Again, thank you all for the help and guidance.

[David Tilston]

Can you post a picture of the furnace?