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Ground Source Heat Pumps

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  • PatrolPatrol Forumite
    85 posts
    Fifth Anniversary Combo Breaker
    mo 00.00-00.00 and so on, which I believe means 4.2 is disabled for me.
  • lovesgshplovesgshp Forumite
    1.4K posts
    Ninth Anniversary 1,000 Posts
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    MMMMM. mine was the same, but thought I would experiment a little more.
    Knew that DHW peak, would supposedly activate around 12.00 today. Changed 4.2 Sunday to 12.00-13.00 and yes, we went to 65C before cutoff on the DHW.
    I need to investigate further, as have never really gone into the DHW, so quite interesting.
    As Manuel says in Fawlty Towers: " I Know Nothing"
  • beardymarrowbeardymarrow Forumite
    152 posts
    Sixth Anniversary 100 Posts Combo Breaker
    Patrol wrote: »
    mo 00.00-00.00 and so on, which I believe means 4.2 is disabled for me.

    Same for me. It's only 4.3 which I restrict.

    DHW peak set daily. In 4.3, DHW is set to be off overnight except on Saturday night/Sunday morning. DHW peak only kicks in at 1am on Sunday. No other days.
  • lovesgshplovesgshp Forumite
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    Thanks guys.
    Checked my DHW peak and it is operating normally. Because my tank is smaller then it is only taking about 20 mins to finish, therefore reflecting the 36hrs extra heat over the years.
    The DHW peak will not operate if it is within the timed settings.
    To be honest, if you are using the DHW on a regular basis, then I would adjust the timer, as you will save more money. I have no clients here on less than a 30 day setting and they are all alive!!!
    As Manuel says in Fawlty Towers: " I Know Nothing"
  • beardymarrowbeardymarrow Forumite
    152 posts
    Sixth Anniversary 100 Posts Combo Breaker
    lovesgshp wrote: »
    Thanks guys.
    Checked my DHW peak and it is operating normally. Because my tank is smaller then it is only taking about 20 mins to finish, therefore reflecting the 36hrs extra heat over the years.
    The DHW peak will not operate if it is within the timed settings.
    To be honest, if you are using the DHW on a regular basis, then I would adjust the timer, as you will save more money. I have no clients here on less than a 30 day setting and they are all alive!!!

    I've only got the option of Daily, Weekly (I can select which Day) or Inactive, so I've switched mine off. Will switch it on if we go away.

    Must be fairly common for people to have their DHW switched off overnight, in which case it'll never kick in (wonder how many people think it's working, but it never does).

    Cheers

    Beardy
  • PatrolPatrol Forumite
    85 posts
    Fifth Anniversary Combo Breaker
    Legionella test kits look to be single-use and not particularly cheap. If you have lots of taps / showers to test it doesn't look very practical and you have to think about how often to retest. Hopefully this situation will improve over time. Sorry if I sound pedantic about what should be extremely rare circumstances but about 15 years ago several people at one of my employers offices were affected and somebody died so I wouldn't want to play the risk down. There are about 400 cases a year identified in the UK.

    From what I've read temperatures of 50C restrict growth in the cylinder and 65C should kill it off. That then leaves outlying items such as shower heads as typical sources particularly if they are rarely used. 65C in the cylinder won't help these and running them for a minute or two before use can mean the room is exposed and breathing in it can be hazardous. Ugh.

    As an aside;
    I repaired a shower head last night and the interior was about 75% coated with a very thin layer of iron (will be down to the earlier borehole problem I mentioned) so I assume my entire DHW circuit is similar). It doesn't come off if I scrape it but my suspicion is that it offers more surface area for bacteria).

    Current settings
    - DHW at 48C
    - DHW off from 10pm to between 5.45-8am, depending on day.
    - Heating set to 18C
    - Summer disconnect set to 18C
    - Heating reduced by 1C from 10pm to 6am each night.
    - I had set pasteurisation to 30 days 2-3 days ago. Really torn on this one but that's for me to figure out.

    The manual description of 4.1 / 4.1.1 heating reduction shows a 3C drop overnight. Any thoughts on that.
  • lovesgshplovesgshp Forumite
    1.4K posts
    Ninth Anniversary 1,000 Posts
    ✭✭✭
    Patrol wrote: »
    Legionella test kits look to be single-use and not particularly cheap. If you have lots of taps / showers to test it doesn't look very practical and you have to think about how often to retest. Hopefully this situation will improve over time. Sorry if I sound pedantic about what should be extremely rare circumstances but about 15 years ago several people at one of my employers offices were affected and somebody died so I wouldn't want to play the risk down. There are about 400 cases a year identified in the UK.

    From what I've read temperatures of 50C restrict growth in the cylinder and 65C should kill it off. That then leaves outlying items such as shower heads as typical sources particularly if they are rarely used. 65C in the cylinder won't help these and running them for a minute or two before use can mean the room is exposed and breathing in it can be hazardous. Ugh.

    As an aside;
    I repaired a shower head last night and the interior was about 75% coated with a very thin layer of iron (will be down to the earlier borehole problem I mentioned) so I assume my entire DHW circuit is similar). It doesn't come off if I scrape it but my suspicion is that it offers more surface area for bacteria).

    Current settings
    - DHW at 48C
    - DHW off from 10pm to between 5.45-8am, depending on day.
    - Heating set to 18C
    - Summer disconnect set to 18C
    - Heating reduced by 1C from 10pm to 6am each night.
    - I had set pasteurisation to 30 days 2-3 days ago. Really torn on this one but that's for me to figure out.
    Do not worry about it too much. If you are using lots of hot water, then you should be perfectly OK.

    The manual description of 4.1 / 4.1.1 heating reduction shows a 3C drop overnight. Any thoughts on that.
    The 3C drop in the manual, is based on a radiator system. With a combined system, then for UFH the max would be -1.5C. As these are only return temps to the pump and not room temps, then there is not a long reheat time.
    I would also tend to reduce the summer disconnect to 16C, as this will switch the circulating pump off, change it back to 18C in the autumn as the temperatures cool.
    So pleased that both you and Beardy have managed to get up to speed on the system and understand it more:beer:
    As Manuel says in Fawlty Towers: " I Know Nothing"
  • PatrolPatrol Forumite
    85 posts
    Fifth Anniversary Combo Breaker
    Should the room temperature setting be kept in step with summer disconnect. e.g. if it is 16C outside and 17C inside would the GSHP try to get the house to 18C (set value) and would the circulating pump switch on in that situation.

    Not that my house ever seems to drop to 17C during summer.
  • lovesgshplovesgshp Forumite
    1.4K posts
    Ninth Anniversary 1,000 Posts
    ✭✭✭
    The summer disconnect overides the other settings, so the 3 way valve will move to the DHW side.
    As Manuel says in Fawlty Towers: " I Know Nothing"
  • PatrolPatrol Forumite
    85 posts
    Fifth Anniversary Combo Breaker
    Set to 16. Since changing the valve on 16 May the pump has been on 30 hours with 2 hours additional heat in 28 days & that should reduce with less frequent pasteurisation.
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