@marvinator80 ahhh, right, check the cylinder stat. Here's the info for that stat in Appendix A p.30. When the stat is demanding heating, the green LED should flash. When you turn the dial, it should briefly show the set point temperature, then revert to the current cylinder temperature.
If you programme hot water once or twice a day through a timer rather than 'on demand' then the LED will be flashing most of the time and only stop after demand is satisfied and the tank is charged to temperature. It will start to flash and call for hot water heating when the probe falls by 4degC hysteresis. I had to have the stat replaced on my Grant cylinder, it was faulty. My installer said it was a known issue with a dodgy batch of stats. Same symptoms as you describe, turn the stat but nothing changing on the display. Grant replaced it PDQ and were very good.
If the stat is dodgy, then maybe your hot water is not charging. When hot water is demanded the two port valves on the pre-plumb cylinder will change over, also, the ASHP will also stop for a few minutes and restart. The light on the heating circuit motor will go out, and the light on the hot water circuit motor will light up. If nowt is happening use the immersion. (Your installers should have checked all this mind, but the stat might have packed up as they drove off, sods law n'that)
This post was modified 2 years ago 3 times by AllyFish
@allyfish thanks again Ally. I had looked in the manual and was doing as you described but it wasn’t working. HOWEVER, I whatsapped the engineer and he told me I had to turn it clockwise and anti clockwise all the way repeatedly and when I did this after the 3rd turn it flashed up “C5”. I was then able to change the target temp!
Just got my new EPC post heat pump installation and I’m delighted. Guy said that after my solar is in there is nothing else I could do to bring score up as it’s not a passive house or whatever but it’s as close as can get.
@marvinator80 you got lucky on the SAP EPC lottery! I went up from a D to a C. My heating and hot water scores both went DOWN after ASHP and solar with diverter from 'average' to 'poor'. My old oil boiler was 80% efficient at best, the ASHP is 250% efficient for HW, 350% efficient for heating, and solar PV is free HW via the iBoost diverter. SAP is a broken system. One of the recommendations to improve my EPC was solar water heating, eh? Which I did, solar PV via a diverter. SAP apparently only recognises solar water heating through a solar thermal collector. 😉
@marvinator80 you got lucky on the SAP EPC lottery! I went up from a D to a C. My heating and hot water scores both went DOWN after ASHP and solar with diverter from 'average' to 'poor'. My old oil boiler was 80% efficient at best, the ASHP is 250% efficient for HW, 350% efficient for heating, and solar PV is free HW via the iBoost diverter. SAP is a broken system. One of the recommendations to improve my EPC was solar water heating, eh? Which I did, solar PV via a diverter. SAP apparently only recognises solar water heating through a solar thermal collector. 😉
I suppose it very much depends upon the level of competence (or possibly intelligence) of the person carrying out the assessment. 🙄
So far things are looking promising on the economy/consumption side.
Based on electricity used in the first 11 days, we have spent slightly less that we were spending on oil, but at the same time we are comfortably heating the whole house whereas before we were leaving large areas unheated or on low heat.
So we have a more comfortable home and are spending slightly less. And now we don’t have the noise of the boiler firing directly underneath our bedroom. That is invaluable.
This being January I am encouraged. Hopefully a gap in terms of economy will open up as the months pass and weather warms throughout the year. But we already had a warmer home for slightly less and the elimination of a noise nuisance.
I’ve noticed that when the temp hits 9 or 10 outside the pump doesn’t seem to have to work at all and is sits with everything turned off for long periods.
I’ve also changed my hot water from schedule to Always On. It seems to work better for us. knowing that anyone might want a shower at any time of the day it means I don’t have to think about it, just as I didn’t have to with the oil boiler.
So, no worse off in terms of function, noise eliminated, whole of house warmer and more comfortable and slightly cheaper in January than which I was on before.
So far things are looking promising on the economy/consumption side.
Based on electricity used in the first 11 days, we have spent slightly less that we were spending on oil, but at the same time we are comfortably heating the whole house whereas before we were leaving large areas unheated or on low heat.
So we have a more comfortable home and are spending slightly less. And now we don’t have the noise of the boiler firing directly underneath our bedroom. That is invaluable.
This being January I am encouraged. Hopefully a gap in terms of economy will open up as the months pass and weather warms throughout the year. But we already had a warmer home for slightly less and the elimination of a noise nuisance.
I’ve noticed that when the temp hits 9 or 10 outside the pump doesn’t seem to have to work at all and is sits with everything turned off for long periods.
I’ve also changed my hot water from schedule to Always On. It seems to work better for us. knowing that anyone might want a shower at any time of the day it means I don’t have to think about it, just as I didn’t have to with the oil boiler.
So, no worse off in terms of function, noise eliminated, whole of house warmer and more comfortable and slightly cheaper in January than oil which I was on before.
Wee update. Installed on 18th of Jan and now on 17th of Feb we have used exactly 1000KwH.
given the time of year, burn in and tweaking required I’m quite happy with that.
Garage build is charging on so hoping to have my solar panels and battery up and running in the next 6 weeks.
That's pretty good. I'm sitting around 920kWh for the last rolling month, but that's mains power. My solar PV contribution has been around 150-180kWh or 5-6kWh a day. All-in I could be using up to 1100kWh. (Don't have my latest usage statement yet.)
We charge the 6.5kWh battery twice a day on Cosy Octopus, and the charge/discharge cycle efficiency is about 90%. The 10% lost keeps our airing cupboard cosy at around 30degC, which is ideal for clothes drying as we don't have a tumble drier! Charging the battery that way has reduced our monthly bill by 20%, simply by moving some daily consumption onto a lower rate tariff. It also uses the battery in winter, when it would otherwise not really be contributing much in the grand scheme.
Right now my 9 panel 3.6kWh array is, at 11am in winter, providing 2.2kWh, over 60% generation with a low solar inclination angle. It did exceed nameplate just after we got it last year in the Autumn. 1.4kWh is being used, 0.9kWh is charging the battery, which is at 75%. Nothing imported from the grid. 🙂 The battery will discharge at 1pm when the daily 1hr hot water ASHP boost starts. That'll draw about 3kWh. At 2pm it'll charge up again via mains and solar on low tariff, and last us through the 4-7pm peak tariff rate and most of the evening standard tariff.
It's strangely satisfying, and a bit addictive, monitoring your own micro-generation, and how you can use variable tariffs and battery storage to save on the cost of what you import. Working from home full time it's nice to have the background heat on all day and know it's not costing a fortune in oil. I would not have had the oil boiler running during the day, I would just heat a couple of rooms with oil filled electric radiators. But for the same power they used to consume, I can now have most of the house heated to 19-20degC all day 🙂
Hi folks, all still going well with this. I’ve no complaints.
It’s a hot day here, first one of the year and I’ve seen it do something I’ve never seen it do before. I can’t find an explanation of this system in the manual. Also I can see that my underfloor heating in the hall is calling for heat at 17.5 degrees but the valve in the cylinder isn’t on and no heat is coming.
@marvinator80 it does this with my 10kW. Algorithm within the ASHP as it monitors air and return water temperature. It’ll turn the ASHP off for a length of time, maybe an hour or two, even if the there is demand. The ASHP will disable if the outdoor ambient is above 20degC. At temperatures approaching this it modulates heat input by cycling on and off over long time intervals
@marvinator80 it does this with my 10kW. Algorithm within the ASHP as it monitors air and return water temperature. It’ll turn the ASHP off for a length of time, maybe an hour or two, even if the there is demand. The ASHP will disable if the outdoor ambient is above 20degC. At temperatures approaching this it modulates heat input by cycling on and off over long time intervals
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