12' Series RM2553 Fridge Options

A hot flu under Gas or Power means the burner and elements are okay ......

It could be age has caused the refrigerant to block up but if its been stored level and youv'e done a run in it, I doubt its the issue as the run should have shaken things up...

Loss of refrigerant is a possibility, with such a long period between use it could have leaked out and you wouldn't have smelt it, unless you recall a strong smell of Cats Pee lingering around ... The refrigerent is ammonia so stinks.

Thermostat on these manual jobs can be an issue, if you fire it up with thermostat set to coldest the gas burner should roar away at full noise and once turned to the warmest setting the burner should drop right back, been awhile now since Ive fiddled with one but I think we gave each setting a good 10 mins or so to settle , at the time it was the switch causing the problem, not expensive just a big pain to get at as the fridge does need to be removed .........
If its gurgling I think thats a sign of the refrigerent just not getting to vaporise, so thermo issue is the most likely if the flame doesn't vary in intensity ...

A new thermostat to suit Part# 2931336016 from Caravans Plus is $210 so be aorund the $200 smackers ....

When mine went after some 10 years or so, it didn't cool but when I went to check at the back, Cats Pee hit me so I knew it was stuffed, if you pull the fridge out and have a close inspection of the back you may see a rusty crack in the fins/tank areas ...........
Repair at these ages I didn't think was a good idea so did a measure up and got a new one and while waiting for it to be delivered I gave the fridge cavity a remodel with proper insulation and sealing, upgraded my fan block ...

I looked at compressor fridge but while cost was similar the extra battery storage pushed it into too many $$$ and with proper insulation fitting mine now works just as good as compressor job ............. If you do replace look for a 2 door job if one will fit int he space as a decent freezer is a god send.

Bought my new fridge from Dometic in Brisbane as it was cheaper delivered than from other RV Shops. ....



Hope that helps ............

You will have to run it on gas for a bit until the flu gets Hot anyway, then adjusting the dial should throw a change in gas flame ... I'm not sure how you would check using power though ... If the flame stays the same and the flu doesn't get hot to touch then it does look like the thermostat ... after an hour the flu should be hot,hot burnies ......

The flame won't be a biggie like on the HWS but you will see a change ...

The piping and fins at top of should be very hot, hotter on one side than the other, if you have a thermometer they can be up in the 50-60c area though maybe a bit less in winter but still hot to touch ..............

The gurgling while I'm not 100%, actually didn't notice when mates was stuffed we just took the gamble, does seem to point that the boiler isn't getting hot enough to boil the liquid but the pics of the burner do show it as being very hot by the glow of the hot burner itself so I do wonder if the plumbing has blockage, the ammonia can form crystals which block the pipes, description Ive read makes it sound like blocked arteries .............. The remedy for that I have been told is to pull the fridge out and turn it upside down, leave it that way for a day or to then refit it, I have been told if its a blockage then that will fix it but never been there myself ( if you pull it out if there's any yellow colouring on tank or pipes then you have a leak.)

So since you would have to pull it out to replace the thermostat, ( not to be confused with the thermocuple,) it wouldn't be a biggy to up end it and see anyway, if no good you could then order a thermostat and while waiting insulate the fridge cavity ....

I would take a stab at it being the thermostat so I suppose a $200 gamble on one if your up to DiY, new fridge about $2500 or a fridge mechanic but needs to be one familiar with 3 way fridges .........

Thats about all I can namage, be more help if I could see and touch ... If you DiY all power needs to be disconnected along with gas and be gentle with the gas fitting and label everything .. when back together do a leak test with soapy water on your gas connection.

Drover said:

The piping and fins at top of should be very hot, hotter on one side than the other, if you have a thermometer they can be up in the 50-60c area though maybe a bit less in winter but still hot to touch ..............

The gurgling while I'm not 100%, actually didn't notice when mates was stuffed we just took the gamble, does seem to point that the boiler isn't getting hot enough to boil the liquid but the pics of the burner do show it as being very hot by the glow of the hot burner itself so I do wonder if the plumbing has blockage, the ammonia can form crystals which block the pipes, description Ive read makes it sound like blocked arteries .............. The remedy for that I have been told is to pull the fridge out and turn it upside down, leave it that way for a day or to then refit it, I have been told if its a blockage then that will fix it but never been there myself ( if you pull it out if there's any yellow colouring on tank or pipes then you have a leak.)

So since you would have to pull it out to replace the thermostat, ( not to be confused with the thermocuple,) it wouldn't be a biggy to up end it and see anyway, if no good you could then order a thermostat and while waiting insulate the fridge cavity ....

I would take a stab at it being the thermostat so I suppose a $200 gamble on one if your up to DiY, new fridge about $2500 or a fridge mechanic but needs to be one familiar with 3 way fridges .........

Thats about all I can namage, be more help if I could see and touch ... If you DiY all power needs to be disconnected along with gas and be gentle with the gas fitting and label everything .. when back together do a leak test with soapy water on your gas connection.

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I do not believe it would be the thermostat. Ian advised to feel the piping above the burner (not the burner itself!) which should be bluddy hot and then again just before the condenser fins. That too should be very hot! Any liquid/ gas that has managed to reach that point then has the heat dissipated by the finned area, hotter on input side and slightly cooler but still hot on the output side. If this is NOT the case, it is a fair indication that the hot refrigerant has NOT reached this area because it has a blockage in the percolator tube at the boiler. As the gas heater seems to be working strongly, the gurgling sound is probably the refrigerant boiling and boiling and not able to proceed further up the tubing. Sounds like the death knell for your fridge unfortunately. Incidentally, you should forget about checking the fridge part as the freezer gets first dibs at any cooling. Below is the best link to how his happens and what occurs when percolator tube is blocked.

Electrical 3 way fridges must be level - see what happens when not correct​

• Thread starterBoots in Action
• Start dateFeb 26, 2021
• TagsNone

Manage to go back and find this very relevant video which should clarify the problem for you @Expanadaman .

Yep @boots that is probably it but need to cover the simple/obvious things first ....... Hard when you can't touch the things....

Pull it out, turn it turtle for a day and see if it then works, if not then try the thermostat, small price to pay if its DiY ,still saving hundreds as its about the same as the tech would do unless he just goes its stuffed get a new one.....lol,lol...

Thats weird, my last reply done after your reply @Expanadaman yet it never showed on my end.............................

That dimpled pipe should be near enough to burny to touch, you certainly have the temps if in the 50/60 range but the cats pee smell, if it made your nose wrinkle and your eyes sparkle it does point to end of the road ... to find it you will have to remove the fridge really and somewhere amongst the plumbing on the return side I would say is a pin hole, a very tiny hole, possibly a tiny stress crack which at present only opens when things get Hot, you should find a yellow stain, it doesn't show up unless theres a leak but you may not see it from the vents as it does seem to be a tiny leak otherwise it would all be gone and no hot pipes so none of the faceache stuff of it happens sometimes, it doesn't vent, so its stuffed when you smell the cat, so start window shopping and don't bother wasting time trying for a fix, some may say it can be repaired, which it could but its a sure sign the time is up as fatigue and age will just throw more problems ..

Here's a link to my Van Thread when I replaced mine, https://expandasdownunder.com/threads/drovers-new-rig-big-mal.8414/page-27
sadly the pics have gone but further on there are some pics of the cabinet upgrade I did ................ Over time I have replaced 2 dead fridge, only one mine and refurbished about 4 or 5 cabinets to improve the insulation and performance of the 3 ways, one of my mates was going to go for a compressor job but after the improved insulation didn't bother and spent the money on touring instead..........

Below is what passed as insulated fridge cabinet by manufacturer, 1/2 inch styro sheet, BS.....

.............. I have an after post but can't find it....

............. where my leak burnt the back of fridge behind boiler/flu.....

................. boiler beside flu, burner removed and showing yellow on tray below boiler/burner .

My thread is big and a lot of waffle from everyone but some good info and after 2024 the pics are still there so may find some ideas...

.... Now properly insulated,well nearly there, vans are not square, caused great problems.

Expanadaman said:

Latest result - checking inside the top inspection vent area, the pipe that comes up from the bottom boiler is rather hot ie 50-60 as suggested and hot going into the condensor fins on the left hand side. That pipe comes up from boiler and then goes across the top then does u tuns back into the fins on the left hand side. That pipe has those dimples punched into it for half its track across. That pipe then goes through the fins from the left side then, out of fins on the right side then u turns back through the fins, this is quite cool, and cool at the u turn on the right hand side of the fins and also as it exits the condensor fins.
Worst part was while I was doing this and sticking my snout in the top vent area, I got a whiff of what I'm assuming is the dreaded "Cat Pee" smell, the heated pipe seems to have fired it up and at the top vent area I could smell it easily enough, not that nice really and does seem to have stuck in my snoz bit like an acid like smell !!!
Guessing I'm on the start again trail now.
Thanks for the help and advice, good to know that we have this forum resource and obliging members to keep the dream alive.
Cheers

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Well @Expanadaman, that appears to have solved your dilemma., unfortunately not the way you had hoped. As the video stated, the whole system, including the hydrogen, is pressurized to 300psi and that will find a fault anywhere in the system. As the video explained, the hydrogen is introduced to lower the boiling point of the liquid ammonia and without that no cooling will occur. And the hydrogen would have escaped with the ammonia gas. From the photos of @Drover's failed unit, you will see that his break was low down below the boiler. It appears that your break is somewhere at the top so the yellow sodium chromate (in the ammonium solution to reduce corrosion) may not be as visible. But the smell is a dead give away!! Looks like it may be a good idea to run fridge occasionally to keep refrigerant and anti-corrosion liquids circulating. even when stored. Good luck.

Its actually a damn sight easier to just buy a new bugga so long as its the same size as the old one, probably cost less than some fridge mechanic trying to fix a busted one ...............................

I would measure up the cabinet and look for a 2 door that will fit the cavity, less work and a 2 door gives you a decent bit of freezer space and overall work better...... If your handy with wood butchering look to see if you can increase the cabinet area and stick a bigger fridge in place ..


Use house roof insulation, the fluffy stuff with alfoil on one side to line the cabinet and outer van wall, works a treat, fasten with staples is best, leave no daggy bits and fridge will slip into place, I run a strip of sticky door seal about 50mm in from back end of fridge so the bottom mashes it and stops the dust from shuffling under later on ......... Any entries to inside of van once cables run I close them up with a handfull of left over fluffy insulation and often run an extra alloy baffle plate on wall by burner/flu and on floor under burner, seems these new ones have less then older models, a few extra heat baffles never hurt...

Drover said:

Its actually a damn sight easier to just buy a new bugga so long as its the same size as the old one, probably cost less than some fridge mechanic trying to fix a busted one ...............................

I would measure up the cabinet and look for a 2 door that will fit the cavity, less work and a 2 door gives you a decent bit of freezer space and overall work better...... If your handy with wood butchering look to see if you can increase the cabinet area and stick a bigger fridge in place ..


Use house roof insulation, the fluffy stuff with alfoil on one side to line the cabinet and outer van wall, works a treat, fasten with staples is best, leave no daggy bits and fridge will slip into place, I run a strip of sticky door seal about 50mm in from back end of fridge so the bottom mashes it and stops the dust from shuffling under later on ......... Any entries to inside of van once cables run I close them up with a handfull of left over fluffy insulation and often run an extra alloy baffle plate on wall by burner/flu and on floor under burner, seems these new ones have less then older models, a few extra heat baffles never hurt...

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I agree totally. Some good ideas there Ian, The whole fridge area must be sealed off from the inside (living area) of van so no combustion gases can enter. So the application of one sided rubber sponge tape with adhesive on other side is essential. I noticed this seal on my fridge when I removed it, only mine is attached to the front area where it meets the front of cupboard opening. I too was able to fit a second baffle to inside of back fridge space so more air is directed THROUGH the condenser fins., as well as improving insulation. Every bit helps and you are getting the best performance when it gets really hot. Happy modifying @Expanadaman.