Working out Air Source Heat Pump running cost?

2

Comments

  • matelodave
    matelodave Posts: 8,608 Forumite
    First Anniversary Name Dropper Photogenic First Post
    edited 30 November 2017 at 9:40AM
    Ttis is what I've got https://www.energyhive.com/dashboard/dave which allows me to monitor my energy consumption. You can monitor it on a PC, phone or tablet and download the data if you wish

    There's a similar device made by Efergy (The Efergy Engage which seems to use similar software and the same servers) Maplins are flogging them off cheaply at the moment, if you can find any left in their stores. £20 for a hub and transmitter. https://www.maplin.co.uk/p/efergy-engage-hub-kit-n67nw

    Mine is monitoring the whole house, but as I've had it for several years I've got a pretty good idea of how to read it so I know what's on and when and most of it is for the heating at this time of the year.

    It's possible to get extra transmitters to monitor different circuits. The sensors clamp around the supply cables so there's no requirement to make connections to the mains supply/ Although if you wanted to monitor just one device, like your heatpump, you'd have to clamp it round the live conductor in the cable that feeds it.
    Never under estimate the power of stupid people in large numbers
  • Cardew
    Cardew Posts: 29,036 Forumite
    Name Dropper First Anniversary First Post Rampant Recycler
    edited 30 November 2017 at 12:06PM
    matelodave wrote: »
    If you are having to provide meter readings to get RHI then you should have two meters, one is the heat meter which works out how much energy your unit is producing and you should also have a separate electricity meter to record how much electricity you are inputting. so your RHI should be based on the difference between the two

    Hi,
    I must admit to knowing little about the detail of RHI payments, but I cannot see how you can have a heat meter to measure energy the ASHP is producing.

    Even if a meter could measure the energy produced, what is the relevance of the figures obtained? If you and I have identical houses and ASHPs yet I am wasteful and use twice as much 'energy' as yourself, would I get twice the RHI payments? If not what is the point of measuring the energy produced?

    From: https://www.ofgem.gov.uk/system/files/docs/2017/10/essentialguideforapplicants_rpiia_4.1_october_2017.pdf
    Most people won’t need to install meters to join the
    Domestic RHI and will be paid based on the annual
    heat demand figure listed on their EPC,
    My 'back of a fag packet' understanding of the RHI system for ASHP was was that the heating/hot water demand of the house was assessed by EPC - say 15,000kWh - and the COP(SPF) was assessed by MCS - say 3.0 - and the RHI payments were based on those assessed figures.
  • sam108
    sam108 Posts: 3 Newbie
    HI,
    We just installed an ASHP which replaced an old combi boiler.
    It is used for domestic hot water and heating.
    We have the old radiators which are used.

    Our last bill for the month came to around £700.

    I have now started to monitor the electricty usage of the ASHP as it has an electrcal meter fitted. It is using around 100KwH a day.....

    This is around £470 per month just to run the ASHP for elecricity usage....

    Can someone help? IS this normal?

    Its a 4 bed detached house, temperature is set at 22 but never gets above 19.5 at the moment

    BUt my biggest worry is the huge electricity bill per month £500 is almost another mortgage....

    I checked online and most are saying that the average running cost should be around £1100 per year.....but we are looking at almost £6k running costs

    Any help or direction most appreciated?
    Maybe the intsaller has not set this up right

    many thanks
    sam
  • lovesgshp
    lovesgshp Posts: 1,413 Forumite
    First Anniversary First Post
    You should be looking at a lot lower cost for that. I will presume you are using radiators.
    You need to check all the pump settings .....flow... cutoff ...etc. It could be a installer error and also the pump operates continuously even with no heat demand.
    Give us the pump model, size of house and we may be able to provide more help.
    As Manuel says in Fawlty Towers: " I Know Nothing"
  • sam108
    sam108 Posts: 3 Newbie
    Hi Lovesghp,

    Thanks for your reply- model is Samsung Air To Water Heatpump Monoblock 16kw model AE160JXYDEH

    House is 4 bed detached; 3000sq feet

    using radiators which were there before with combi boiler

    I've checked with installer and he says this is normal (but surely 100kwh is way overboard?) - or am i missing something....
  • matelodave
    matelodave Posts: 8,608 Forumite
    First Anniversary Name Dropper Photogenic First Post
    edited 30 January 2019 at 5:29PM
    What is your heating flow temperature and what temperature is your hot water.

    IMO it's never a good idea to just bung a heatpump onto an existing system because the radiators are seldom sized to allow the pump to run at it's optimum temperatures - ie between about 35-45degrees. Anything over about 50 degrees will require the use of the boost or back-up heater which will be using peak rates electricity.

    What controls have you got? and what are they set to, what timings. If you are trying to run it like your old boiler with a couple of hours in the morning and a couple at night then it will be flogging it's heart out and you'll still be cold.

    It took me my first winter to get it tweaked properly but our system was matched to the heatpump rather than just bunging one on in place of a boiler. Our flow temperatures are between 30-40 degrees unless it's everso cold when they might creep up to 42. Our hot water is also just heated 45 degrees but boosted to 60 degrees to sterilse the tank once a week.

    We dont turn our heating off, just down by 3 degrees overnight and then back up in the morning - we are at home all day so it runs virtually continuously at this time if the year.

    Have a look at the link in post#12 above to see how our energy consumption varies and you can see the unit runs at night as well.

    I can get through between40-60kwh a day in this weather but my overall average consumption for this January will be around 1100kwh (about 35kwh/day)which is what I expect. That's all our energy including generous use of the washing machine, tumble dryer, dishwasher, cooking etc etc. Our worst January was in 2013 when we used 1500kwh (nearly 48kwh.day).

    Our detached bungalow is about 1350sq.ft but it's roof is pretty big, however it got lots of insulation u there (over 300mm) the walls are brick with some insulation in them and the windows were double glazed in 1999
    Never under estimate the power of stupid people in large numbers
  • matelodave
    matelodave Posts: 8,608 Forumite
    First Anniversary Name Dropper Photogenic First Post
    Check out post#15 on this thread - dunno if it affects yours

    https://forums.moneysavingexpert.com/showthread.php?p=75394313#post75394313
    Never under estimate the power of stupid people in large numbers
  • Cardew
    Cardew Posts: 29,036 Forumite
    Name Dropper First Anniversary First Post Rampant Recycler
    sam108 wrote: »
    HI,


    I have now started to monitor the electricty usage of the ASHP as it has an electrcal meter fitted. It is using around 100KwH a day.....

    This is around £470 per month just to run the ASHP for elecricity usage....


    sam



    Are you sure that the heat pump is not using the 'back up' internal immersion heater for much of the time?
  • lovesgshp
    lovesgshp Posts: 1,413 Forumite
    First Anniversary First Post
    edited 30 January 2019 at 8:34PM
    I think as Cardew says that the backup heater is activating. Do not use the system as a normal heating system with on /off controls. They are not meant for that. 3C rad temp minus overnight for rads.
    Have you a menu to say what the power distribution is ?
    As Manuel says in Fawlty Towers: " I Know Nothing"
  • SusanF11
    SusanF11 Posts: 4 Newbie
    Just wondering if you have found a solution to your heating issues?

    We too are experiencing very high running costs.
This discussion has been closed.
★ ★ ★ Meet your Ambassadors

Categories

  • All Categories
  • 343.2K Banking & Borrowing
  • 250.1K Reduce Debt & Boost Income
  • 449.7K Spending & Discounts
  • 235.3K Work, Benefits & Business
  • 608K Mortgages, Homes & Bills
  • 173.1K Life & Family
  • 247.9K Travel & Transport
  • 1.5M Hobbies & Leisure
  • 15.9K Discuss & Feedback
  • 15.1K Coronavirus Support Boards