Dometic RMDT 8505 - Cooling problems again

Discussion in 'Fridges & Ovens' started by Rob Baldwin, Jun 11, 2018.

  1. Rob Baldwin

    Rob Baldwin

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    Hi I'm having a problem with my Dometic RMDT 8505 fridge freezer. Last week we travelled to campsite 1 - no problems Fridge/Freezer switched to 12v whilst travelling, on site plugged in to 240v again no problems. We moved to site 2 and the fridge/freezer worked whilst travelling again but once on site and plugged in to the mains, overnight we noticed the fridge and freezer had stopped cooling. I tried unplugging the mains, switching off, etc but the unit failed to cool. The motorhome was sited level. I switched to gas & the freezer section cooled overnight but the fridge failed to cool. This continued for 2 days, freezer froze but the fridge only seems to cool a small amount even after increasing the thermostat levels to five lights. Returning home and the unit switched to 12v again and both the freezer maintained frozen and the fridge did cool things done at an increased level.

    On returning home I have switched the unit off waited 24hrs and doors open, fridge is at ambient temperature

    Switched back on again mains voltage - 24 hrs later freezer frozen & fridge very cool temp setting on 4 led’s

    Switched off waited 24hrs and doors open, fridge is at ambient temperature.

    Repeated these steps switching from mains to gas every 48 hours and all ok until this weekend. The unit was on elec and Sun morning I have a HE1 error code. This is Heating Element number 1 but I have 265ohms & mains voltage when testing? any thoughts??
     
  2. sallylillian

    sallylillian Funster Life Member

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    I had multiple failures on my 8 series fridge. I had no errors on the panel as you have however it would not cool with 230vac. At this point the van was 1 year old, and I had a warranty replacement whilst in Spain of the element which had definitely failed. Then OK for a few weeks, up in the Lakes the unit was cooling eraticly on 230vac indeed it may have been before. Anyway switching to gas and the system worked fine. The end result which my local dometic dealer found was that the condenser was likely failing or the gas was contaminated causing incorrect gassing and liquifying. Using gas provided a more robust heat which forced the circulation and the 230vac element was too localised to overcome the issue. The whole condenser was replaced, an easy job once the fridge was out. Is yours now out of warranty? If so I determined that if that had been the case with mine, the condenser is so expensive it would be only slightly more expensive to get a complete new fridge!
     
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  3. Rob Baldwin

    Rob Baldwin

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    Hi Michael - thanks for the reply. The unit is nearly 6 years old so no chance with warranty. The unit already has had 2off new 240v elements. But Im beginning to think that the coming unit (I think you call that the condenser) is intermittent failing. Further to my testing - Dometic have told me the element should be 600ohms. (In my experience elements either work or don't) so why mine is 265ohms I'm not sure. The element gets warm.
    To add a bit more history;
    Since testing the element;
    Monday Am - put fridge back on AES Led 3 lights (Pipes hot at the base, warm @the top RHS & warmish on the LHS)
    Monday - 7.30pm - Freezer temperature - 27.6’, Changed back to gas @ 7.30pm - 10pm Monday Freezer Temp @ 19.7’
    Tues 9.25am Freezer @ 13’ - Fridge at 14.4’
    Any help would be greatly appreciated
     
  4. sallylillian

    sallylillian Funster Life Member

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    The gas in the condenser is not serviceable, so if it has a small leak or there is some contaminant in it then you may get the issues you describe, however I have only a small knowledge gleaned from discussions with engineers so not to be taken as experienced advice! But as I have said if it is the condenser (cooling unit) then just start a google search for a new fridge!
     

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