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Discuss Heat pump low pressure in the Renewable Energy area at

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  1. SmokeyJ

    SmokeyJ GSR


    Is the discolouration on some of the coil piping normal?
  2. Worcester

    Worcester Plumber

    Are you guys sure that unit doesn't have glycol in it??? That looks just like the A series collector, as opposed to an evaporator...
  3. quality

    quality Plumber GSR

    That is 100% a DHP AX the last 2 pictures are of the evapoartor. The ally way its installed in will not help as in cooler weather it will be like walking into a refrigerator which will not help with low pressure issues, But sound as its quite a recent issue I would suggest on the expansion valve being on its way as they do tend to hunt quite a bit because it only a standard mechanical TEV and 5 years service is pretty average life for one. I have replaced quite a few but there were only around 1200 DHP AXunits fitted in the UK
    Last edited: Mar 10, 2016
  4. SmokeyJ

    SmokeyJ GSR

    Thanks quality will look into that. I'm a bit reluctant to look into any flow related issue as seems thats the route the previous company took with no avail.
    Will have to get our refrigerant guy to test the system. With the TEV is that something you can test or would it be better/cost effective to just change?
    Also a little confused now as to wether this system needs glycol? Manual just says fill off the mains, just a normal filling loop on system so don't think so.
    Last edited: Mar 10, 2016
  5. quality

    quality Plumber GSR

    Just replace it and its sorted
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