Chinkoa Posted October 11 Share Posted October 11 Hi from Reay in the Highland, Our house faces due north, and about as far North as you can get and facing the sea. Next stop the North Pole. We have lived here now for about 18 months. In December 23 I applied for a Local wind farm grant and got a 70% discount on my proposed installation. I January we had installed 5.5Kws oF PV. on the roof feeding a 6KW Hybrid inverter. I then in April I Installed 23.2KW of solar batteries. This worked very well over summer no electricity bills and account getting export credit of £20/£30 per month. In April I applied for a totally free Government funded Heat pump installation and after two on site surveys and jumping through many bureaucratic hoops we were accepted into the scheme. it was all fitted in May. long story short, all interior of exterior walls were clad with 63mm closed cell installation, Totally new Central heating system installed and a 17.5kw "Grant" heat pump installed. Gas boiler Removed. Installation process is another story and not for the faint hearted. Since the heating period kicked in my export credits have crashed and this month I expect to pay for some electricity. My problem is I am totally confused how to control the Heat Pump. Instructions from installers boiled down to don't touch anything and we are off, I have a feeling that the cost of running the heat pump will very very expensive despite the PV which up here will be totally ineffective from mid Nov to mid February. on the plus side the heating in the house is very good and better than the old lpg boiler we had. Colin Link to comment Share on other sites More sharing options...
ToughButterCup Posted October 11 Share Posted October 11 38 minutes ago, Chinkoa said: ...My problem is I am totally confused how to control the Heat Pump. Instructions from installers boiled down to don't touch anything and we are off, ... Firstly , welcome! Nextly, photo of the Heat Pump please and - if possible, a link to the manufacturer's website and - maybe- download the manual ? Link to comment Share on other sites More sharing options...
JohnMo Posted October 11 Share Posted October 11 So really need install details Radiators or UFH No. of thermostats Buffer or no buffer Design flow temp Make model of heat pump (sounds huge). Heat loss calculations. How is it currently set to run, bouncing of thermostat(s) at a set flow temp or weather compensation? Etc... Link to comment Share on other sites More sharing options...
Chinkoa Posted October 12 Author Share Posted October 12 Rads , onto thermostat. Got weather compensation. It's a grant airflow 17 5 kw. Has to be oversize. Going through instructions. Hw. Set at 60c by installers, now set at 50c Working through other manuals. I don't connect very well with written instruction, never have. Prefer to see someone do it then it falls into place forever. Link to comment Share on other sites More sharing options...
PhilT Posted October 13 Share Posted October 13 House size (eg floor area)? Are you saying peak heat loss is 5kW (at what ambient temp?) but the heat pump is a 17kW? Hot water set to 60 continuous will cost you a lot of electricity. Mine is set to 42, for 2 people, timed to heat once a day at 2pm. We only take short showers. If the flow temp is fixed at 50 then it's not set to Weather Compensation. There may be some useful YouTube videos on that model possibly? Link to comment Share on other sites More sharing options...
Beelbeebub Posted October 13 Share Posted October 13 Welcome. As the others have said, what is your setup? The Grant units are pretty good but they are setup from the factory to act like oil/gas boilers so they are more familiar for installers. In particular they tend not to use weather compensation but just set a fixed flow temperature for your UFH/rads and control the temp by turning on and off via a standard thermostat. This can really hit the efficency. There are ways of setting the system to be more efficient. Do you have the white control unit? Link to comment Share on other sites More sharing options...
ReedRichards Posted October 13 Share Posted October 13 On 11/10/2024 at 10:38, Chinkoa said: I have a feeling that the cost of running the heat pump will very very expensive despite the PV which up here will be totally ineffective from mid Nov to mid February. on the plus side the heating in the house is very good and better than the old lpg boiler we had. If you paid for all your electricity then the cost of running the heat pump ought to be less than the cost of running your old lpg boiler (except, perhaps, for the fact that you are making the house warmer with the heat pump). Link to comment Share on other sites More sharing options...
Chinkoa Posted October 13 Author Share Posted October 13 42 minutes ago, Beelbeebub said: Welcome. As the others have said, what is your setup? The Grant units are pretty good but they are setup from the factory to act like oil/gas boilers so they are more familiar for installers. In particular they tend not to use weather compensation but just set a fixed flow temperature for your UFH/rads and control the temp by turning on and off via a standard thermostat. This can really hit the efficency. There are ways of setting the system to be more efficient. Do you have the white control unit? Link to comment Share on other sites More sharing options...
Chinkoa Posted October 13 Author Share Posted October 13 Yes I have the same white controller. what settings do you suggest change and how? Link to comment Share on other sites More sharing options...
Beelbeebub Posted October 13 Share Posted October 13 (edited) Need to work out what setting you have now before any changes. Did they swap radiators, put in new pipework? How warm do they get? Have you got Underfloor? How warm do those radiators get? Is it always the same? Is your HP running continuously or starting and stopping all the time? One thing to note is you will not be able to generate enough electricity to power your HP through the winter. You will be paying for some electricity. If things go well, the extra you pay for electricity will be less than you would have paid for LPG. Edited October 13 by Beelbeebub Link to comment Share on other sites More sharing options...
Chinkoa Posted October 13 Author Share Posted October 13 43 minutes ago, ReedRichards said: If you paid for all your electricity then the cost of running the heat pump ought to be less than the cost of running your old lpg boiler (except, perhaps, for the fact that you are making the house warmer with the heat pump). I have no history of lpg cost in this house as we have only been in it for a short Just now, Beelbeebub said: Need to work out what setting you have now before any changes. Did they swap radiators, put in new pipework? How warm do they get? Have you got Underfloor? One thing to note is you will not be able to generate enough electricity to power your HP through the winter. You will be paying for some electricity. If things go well, the extra you pay for electricity will be less than you would have paid for LPG. Yes all radiators were swapped, Radiators keep the house warm, No underfloor, PV no illusions that i will get anything out of it for the winter months. We have only been in this house for a short time and we have no history of running cost with Lpg. although the short time we used Lpg last winter suggested it would get very expensive for the year. We have a 5kw log burner which we also use this is enclosed in a huge Stone fireplace that absorbs a lot of heat. for instance next morning after the fire has gone out the fireplace is still at 23/26 degrees. As I said all the interior walls of the exterior walls have been clad with 63mm closed cell insulation and the house itself is pretty tight. 1 Link to comment Share on other sites More sharing options...
Chinkoa Posted October 13 Author Share Posted October 13 Just now, Chinkoa said: I have no history of lpg cost in this house as we have only been in it for a short Yes all radiators were swapped, Radiators keep the house warm, No underfloor, PV no illusions that i will get anything out of it for the winter months. We have only been in this house for a short time and we have no history of running cost with Lpg. although the short time we used Lpg last winter suggested it would get very expensive for the year. We have a 5kw log burner which we also use this is enclosed in a huge Stone fireplace that absorbs a lot of heat. for instance next morning after the fire has gone out the fireplace is still at 23/26 degrees. As I said all the interior walls of the exterior walls have been clad with 63mm closed cell insulation and the house itself is pretty tight. Yes new pipe work. Link to comment Share on other sites More sharing options...
sharpener Posted October 13 Share Posted October 13 22 hours ago, Chinkoa said: Rads , onto thermostat. Got weather compensation. It's a grant airflow 17.5 kw. Has to be oversize. Going through instructions. Hw. Set at 60c by installers, now set at 50c There were some extra line breaks, it makes more sense with them removed as above. Yes making sure you are on WC would be the first priority, keep reducing the curve by 0.1 each day until you are too cold and then back one step. No one has mentioned ToU tariffs. If you change to something like Octopus Cosy then yr 23.2 kWh batteries can be charged fully at cheap rate 3x in every 24 hours and will most likely have the endurance to bridge the HP across the peak rate window 1600 to 1900h (or maybe you can program it to be set back or off at those times). u If you have a big enough HW tank also set this to heat up only during off-peak rate. Grant are often installed as S-plan so make sure the heating is off while the HW is on, or your htg flow temp will be unnecessarily high. If you are not on Octopus already there is a discount code which you can spilt with half going to support this forum, I forget the details but one of the mods will be along to tell you shortly(!). Link to comment Share on other sites More sharing options...
Beelbeebub Posted October 13 Share Posted October 13 I assume you have an unvented hot water cylinder. The grant system (assuming they have installed as per instructions) uses a totally seperate anti legionella system basically a timer and immersion you set to go off once a week. So you can set the hot water temp to as low as provides enough water at a hot enough temp for you. The next thing is to check if weather comp is active. It might not be if your installer was not on the ball. The easiest way to check is to feel the rads. Are they warm to the touch, and does that vary? Ie on a cold night are they warmer than a mild day? Do you have a single thermostat or one of each room? Link to comment Share on other sites More sharing options...
Chinkoa Posted October 15 Author Share Posted October 15 On 13/10/2024 at 12:57, sharpener said: There were some extra line breaks, it makes more sense with them removed as above. Yes making sure you are on WC would be the first priority, keep reducing the curve by 0.1 each day until you are too cold and then back one step. No one has mentioned ToU tariffs. If you change to something like Octopus Cosy then yr 23.2 kWh batteries can be charged fully at cheap rate 3x in every 24 hours and will most likely have the endurance to bridge the HP across the peak rate window 1600 to 1900h (or maybe you can program it to be set back or off at those times). u If you have a big enough HW tank also set this to heat up only during off-peak rate. Grant are often installed as S-plan so make sure the heating is off while the HW is on, or your htg flow temp will be unnecessarily high. If you are not on Octopus already there is a discount code which you can spilt with half going to support this forum, I forget the details but one of the mods will be along to tell you shortly(!). I am with Octopus. GB Green and cosy. 17.47p/kw unit rate and 19.95p/day standing charge. that seem a good tariff to be on. I will look at WC. Link to comment Share on other sites More sharing options...
Chinkoa Posted October 15 Author Share Posted October 15 On 13/10/2024 at 13:16, Beelbeebub said: I assume you have an unvented hot water cylinder. The grant system (assuming they have installed as per instructions) uses a totally seperate anti legionella system basically a timer and immersion you set to go off once a week. So you can set the hot water temp to as low as provides enough water at a hot enough temp for you. The next thing is to check if weather comp is active. It might not be if your installer was not on the ball. The easiest way to check is to feel the rads. Are they warm to the touch, and does that vary? Ie on a cold night are they warmer than a mild day? Do you have a single thermostat or one of each room? Yes radiators are warmer at night. Single thermostat in the Hall. Trvs on all Rads but one as you would expect. Link to comment Share on other sites More sharing options...
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