How long should it take for a fridge to cool down?

Discussion in 'Motorhome Chat' started by BobtheBass, Jul 12, 2016.

  1. BobtheBass

    BobtheBass Funster

    Joined:
    Nov 11, 2013
    Messages:
    589
    Likes Received:
    1,507
    Location:
    Tewkesbury
    In our new Carthago we have a lovely Dometic fridge freezer fitted, but I think it may be slightly faulty. On hook up it takes well over a day, probably a day and a half running flat out to reduce the temperature inside to 5 degrees, and that's in the pooey weather we have had since we picked the van up. I haven't tried it on gas and on 12 volts the temperature after a 2 hour drive doesn't seem to drop at all, so my question is, is this normal? It seems to work fine once the optimum temperature is reached, but our last fridge only took a few hours to get there and then the temperature control could be backed right off. You have to leave the new one at least half way otherwise the temperature creeps up. Is anyone out there a fridge boffin? I would add that there is a wall ventilator and a roof ventilator fitted (both uncovered) and an additional ventilator was fitted by Elite lower down as we have had a microwave installed in the cupboard below.
    Thanks,
    Bob
     
  2. Bill_OR

    Bill_OR Funster

    Joined:
    Dec 11, 2011
    Messages:
    453
    Likes Received:
    570
    Location:
    Nr Hastings, East Sussex
    We always put our 'fridge on EHU for 48 hours before we leave. 12v will never cool the fridge - it just keeps it at temperature.
     
    • Like Like x 1
  3. scotjimland

    scotjimland Funster Life Member

    Joined:
    Jul 25, 2007
    Messages:
    28,934
    Likes Received:
    25,574
    Location:
    .
    it shouldn't take that long to reach 5deg ..

    also, the most recent models are fitted with a 12v heater is almost same wattage as the 240v mains heater ..

    do you have a model number that the specs can be checked please .. ?

    http://www.dometicapproved.co.uk/page.aspx?p=maAbsorption
     
    • Like Like x 1
  4. Lenny HB

    Lenny HB Funster

    Joined:
    Oct 18, 2007
    Messages:
    5,246
    Likes Received:
    5,042
    Location:
    West Sussex
    Which model fridge?
    If it the 8000 series they are probably the worst fridge ever made by Dometic and the performance varies enormously between individual fridges. The one in my Hymer the burner sounded like a jet engine and cooling was dreadful wouldn't get below 10 deg on mains and 7 on gas on a cool spring day. Had a new burner fitted, a bit quieter and cooled better, then the ignition leads arced out and burnt through the insulation since I had the burner out to fix it myself (went wrong in Greece last year) it is very quiet now and working much better.
    By contrast the one in my mates Carthago is the other extream and gets too cold.
    The Dometic spec is to cool to 7 deg in 30deg ambient, doesn't exactly meet food safety guidelines.
     
    • Like Like x 1
  5. Lenny HB

    Lenny HB Funster

    Joined:
    Oct 18, 2007
    Messages:
    5,246
    Likes Received:
    5,042
    Location:
    West Sussex
    Why not, Dometic fridges since the 7000 series (not sure about 6000 series) have temperature control on 12v.
     
  6. BobtheBass

    BobtheBass Funster

    Joined:
    Nov 11, 2013
    Messages:
    589
    Likes Received:
    1,507
    Location:
    Tewkesbury
    It's an RMD 8505. Looks like it might not be the best fridge in the world, but thanks for all your help.
     
  7. scotjimland

    scotjimland Funster Life Member

    Joined:
    Jul 25, 2007
    Messages:
    28,934
    Likes Received:
    25,574
    Location:
    .
    from the service manual ...

    mains is 125 watt .. 12 vdc is 120 watt.. so virtually the same cooling


    * note ....setting it too low can have an adverse effect..

    1. Failure: The refrigerator does not cool sufficiently.
    Possible cause

    • Inadequate ventilation to the unit.

    • Thermostat setting is too low.

    • The condenser is heavily frosted.

    • Too much warm food has been stored inside within short period of time.

    • The appliance has been running for only a short period of time.

      Regularly remove ventilation grilles. Failure: The refrigerator does not cool in gas operation mode.
    Ambient temperatures too high.

    Failure: The refrigerator does not cool in 12V operation.

    Action you can take

    Check that the ventilation grilles are not covered. Set thermostat to a higher level.
    Check that the refrigerator door closes properly. Allow warm food to cool down before storage.

    Check whether the cooling compartment works after approx. 4 - 5 ho
     
    • Useful Useful x 1
  8. Robert Clark

    Robert Clark Funster Life Member

    Joined:
    Jul 12, 2014
    Messages:
    5,606
    Likes Received:
    9,770
    Location:
    East Sussex
    We've got the same fridge in our Carthago
    We normally turn ours on a day before leaving UK - the freezer is really good. Keeps ice cream solid
    Makes ice cubes
    Trick not to overfill the fridge or freezer as it blocks air circulation
    We fitted two cooling fans and a digital stat - so it coped even in temps circa 40deg.
    We mainly use on gas and one 11kg bottle has over lasted two weeks including water heating and cooking.
    Seems very economical.
    Mind you I did have to adjust the fridge door as it was not a tight fit.
     
  9. Lenny HB

    Lenny HB Funster

    Joined:
    Oct 18, 2007
    Messages:
    5,246
    Likes Received:
    5,042
    Location:
    West Sussex
    Same as mine, probably the worst Dometic fridge ever.(n)
    @Techno will tell you all about them.
     
  10. BobtheBass

    BobtheBass Funster

    Joined:
    Nov 11, 2013
    Messages:
    589
    Likes Received:
    1,507
    Location:
    Tewkesbury
    By "set the thermostat to a higher level" I assume it means make it colder? Sorry to sound a bit of a dimbo but when I read this in the manual it confused me a bit.
     
  11. Lenny HB

    Lenny HB Funster

    Joined:
    Oct 18, 2007
    Messages:
    5,246
    Likes Received:
    5,042
    Location:
    West Sussex
    Agree the freezer works OK but not impressed with the fridge I have also fitted fans on the top vent, we get through a 14kg cylinder of gas in 3 weeks, with the 7000 fridge in our last van 11kg lasted 3 weeks.
     
  12. Lenny HB

    Lenny HB Funster

    Joined:
    Oct 18, 2007
    Messages:
    5,246
    Likes Received:
    5,042
    Location:
    West Sussex
    Yep, always run mine on 4 bars, doesn't appear to make any difference turning it up to 5.
     
    • Like Like x 1
  13. scotjimland

    scotjimland Funster Life Member

    Joined:
    Jul 25, 2007
    Messages:
    28,934
    Likes Received:
    25,574
    Location:
    .
    yes.. sounds daft but if you set it too cold it has an adverse effect...

    every fridge is different, the trick is to find the 'sweet spot' where it works at it's best.. on mine, on a 0 - 10 dial .. . it works best at about 6

    in France at present with daily high temps of 30+ C .. fridge is working great ..

    I always try to park with fridge vents facing North .. and or under the awning ..and also have two PC fans fitted in the top vent..
     
    • Like Like x 2
Loading...

Share This Page