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M
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Mimi
Rank 1
January 29, 2023
Solved

Why is my Mitsubishi Ecodan not heating up the tank?

  • January 29, 2023
  • 26 replies
  • 8131 views

I have no hot water.  DHW is switched to pause automatically and tank water temperature stays at 14 degrees celcius.  Heating is running fine.  I tried to maual reset but didn’t help.  DHW is also paused automatically and everytime it pauses, “LJ” is flashing at the top left of the control screen.  I have no idea what “LJ” stands for, couldn’t find a clue from the Mitsubishi error code.  Please help.  Thanks

Best answer by M.isterW

LJ - DHW operation error. Either DHW tank water temp thermistor (THW5) has become detached from its holder. Or flow rate of sanitary circuit may be reduced.

 

1 - Check the thermistor 

2 - Check the water circulation pump is working properly.

26 replies

juliamc
Rank 20
juliamc
Rank 20
January 29, 2023

Can you post a picture of the screen with the error code ?

M
Rank 1
MimiAuthor
Rank 1
January 29, 2023

 

    juliamc
    Rank 20
    juliamc
    Rank 20
    January 29, 2023

    I’ve just found someone else referring to error code LJ  on moneysavingexpert… their answer was this: We have hot water. Plumber arrived this morning to discover a switch on the pump was not fully on. All sorted now and all fully operational.

     I have a Daikin so I’m afraid that doesn’t mean much to me!! Does it help you ?

    Are you able to switch on the immersion heater ?

    Is the big 14 on your screen your Target Temperature for the hot water ? The little 14 is the Actual Temperature. Can you increase the Target temperature?

      M
      Rank 1
      MimiAuthor
      Rank 1
      January 29, 2023

      Thanks, I'll check the switches.  Immersion heater is also not working. The big 14 is temperature we set for the heating. The small 14 is the water tank temperature.  Hot water temperature is already set to 50.

        juliamc
        Rank 20
        juliamc
        Rank 20
        January 29, 2023

        There are a few Ecodan owners here: @M.isterW @OrphM62 @Nicllb ??

          M.isterW
          Rank 6
          M.isterWSolved
          Rank 6
          January 30, 2023

          LJ - DHW operation error. Either DHW tank water temp thermistor (THW5) has become detached from its holder. Or flow rate of sanitary circuit may be reduced.

           

          1 - Check the thermistor 

          2 - Check the water circulation pump is working properly.

          1992 4 bed detached house. Solar PV + battery, Zappi EV charger, Mitsubishi Ecodan ASHP and i-life2 fan assisted radiators.... No gas 😊
            M
            Rank 1
            MimiAuthor
            Rank 1
            January 30, 2023

            Will check. Thanks so much 

            N
            Newcomer
            Nicllb
            Newcomer
            February 12, 2023

            @juliamc , sorry can’t help as currently we don’t have a tank. Our Sunamp batteries are being swapped out in March. Hoping you got it sorted, as hoping swapping to a hot water tank will solve our heating problems!

              H
              Newcomer
              hamedj
              Newcomer
              October 21, 2024

              Hi, I have the same problem on my Ecodan, how did you manage to solve this?

              Chris_OVO
              Community Manager
              Chris_OVO
              Community Manager
              October 24, 2024

              LJ - DHW operation error. Either DHW tank water temp thermistor (THW5) has become detached from its holder. Or flow rate of sanitary circuit may be reduced.

               

              1 - Check the thermistor 

              2 - Check the water circulation pump is working properly.

              Hey @hamedj,

               

              Have you tried the above steps? 

              Renewable energy jokes never get old.
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