This ia analgamation of replies on Fridge problems given to others:
Re fridge not getting cold. I agree with another reply that if you have the
fridge more than 3 degs out of level the fridge might not work. The ammonia in
the mix has a dose of chromate in it and this can boil off. My method if the
unit is getting hot and not working is to remove and tip upside down and wait
till the gurgling sound stops. Whilst it is upside down for hour trace the flow
of the solution in the pipes...then with a gas torch heat the pipes and give
them a medium thump with a rubber mallet. Turn the fridge onto the side where
the fluid will go to next and heat and thump as before leave until gurgling
stops. Stand fridge upright and give another heat and thump paying attention to
where the high pressure line comes out of the tank(boiler)...this is the thin pipe.
Now leave for 1-2 hours and then try fridge on electricity (for up to 8 hrs.)
before reinstalling into van. With this heat and pump method you are trying to
expand the steel tubes of the unit and to clear any blockages. BUT before you
do this check the flue to see that the baffle (a twisted piece of metal on a
wire which hangs in flue) is still there and hung into place. If it is missing
or has fallen into the bottom of the flue the fridge will perform like it has a
blockage. Most absorption fridges which are working Gas and Electric have two
thermostats. One which is Gas and the other which is AC. So can presume that it
is unlikely that both will become inoperable at the same time.
Another thing to look at are the thermostat tube attachments to the evaporator
.Are they still attached? Another...In Electrolux or Dometic fridges for example the evaporator attaches
directly onto the unit with screws .Between the the evaporator and the unit is
a layer of conductive paste. Are the screws still tight? Is there anything
covering the fridge vents in the van either at the side of the van or
underneath the fridge. The latter will also cause poor performance.
In most cases the baffle can be
retrieved by inserting a pair of long nose pliers down the flue from the top
end and just lifting it out. The wire usually just hooks over the lip of the
flue.
Another point...if you look at the picture in Michael’s post …for most RV
fridges this is actually mirror reversed...on the right hand side from behind
the fridge you will see the boiler tube covered in insulation material. On
really old fridges this is was of a square shape and on later fridges
cylindrical and indicated that the tube has the later designed boiler tube.
This modification was made so that the fridge would be less susceptible to
blockages due to out of level situations but although it helped it was not a
totally success.
Diagnosing the Cooling Unit:
Three things must be remembered
1. Circulation within the cooling unit is totally gravitational. This means
proper levelling is so important
2. Heat created to boil the ammonia has to dissipate into the surrounding
air.
3. Proper heat at the boiler section.
4. After the unit has been operating for approx. 1 hr. carefully touch the
unit at the boiler box and the absorber area. These areas should be approx. the
same temperature regardless of the outside temperature. Equal heat between
boiler and absorber indicates that fluid circulation is ok
5. If the unit is blocked or partially blocked ...to the touch this unit
will be extremely hot at the boiler with little warmth at the absorber
6. If you have a leaker this unit will be warm at the boiler and extremely hot
at the absorber. In this case you are still boiling ammonia but have no
hydrogen for evaporation. Check for an ammonia smell around the cooling unit
and inside the fridge. This could indicate a leak. Check for any deposits of
yellow powder on the tubing which will sometimes form around the area of a
leak. Yellow deposits around the fill valve can occur during manufacture and
doesn't indicate a leak.
7. If the unit works on one heat source and not another ….this is not an
indicator of a bad unit.
8. Make sure that the fridge is level. Sometimes the vehicle is level but
the fridge is not due to poor installation. Place a level on the bottom of
freezer compartment and check side to side and front to back level.
9. Check door gaskets. A leaking gasket can allow enough warm air inside the
refrigerator to overcome most of the cooling being produced. Use a paper bank
note. Close door on the note. If no resistance is felt when pulling it
out..,the gasket is not sealing properly. Do this on all four sides.
10. Check the venting system to ensure ample air flow is provided at the
back of fridge.
I had one case where a customer’s cardigan and a bath towel had fallen to
the back of fridge.
11. During cold weather don’t heat up your vehicle like an oven inside. These
fridges work best up to approx. 70 degrees fahrenheit outside
temperature(ambient). For every degree that the ambient goes up the temperature
in the fridge will go up 1 degree.
I hope that these few points will lead to som success with your fridge
Regards
vic4114
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Regards
Vic Williams
Brisbane,Australia
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Topic: fridge problem
