If you have a heating and hot water schedule start at the same time, it will ignore the hot water.
Time shift one by one minute and problem solved. It’s a known issue and bizarrely, it’s even covered in the manual in the troubleshooting section.
Heat Pumps: anyone have one/thought about it?
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If you have a heating and hot water schedule start at the same time, it will ignore the hot water.
Time shift one by one minute and problem solved. It’s a known issue and bizarrely, it’s even covered in the manual in the troubleshooting section.
They're at different times, this is another bug. Basically, if I make any changes at all to the heating schedule (i.e just change a temperature on the heating schedule from 20C to 21C for example) the hot water schedule wont start the next night.
ok thanks for that, much appreciated.
No, the form is here:
why do you want to know?
why do you want to know?
Because I signed a contract with Octopus for a Daikin Altherma 3, with installation in January. But I hope Daikin may bring the newer 4 to UK in the mean time.
What type of COP are you guys getting with Daikin Altherma 3?
What type of COP are you guys getting with Daikin Altherma 3?
Even if they bring it to the UK, there is no gaurantee Octopus will offer it and there are different install requirements due to the R290 refrigerant.
Not sure, the low 3.x range - but that doesnt mean its high cost.
My system isn't set up to optimise for effciency, I run my heatpump harder over night with cheap electricty in the heating season and always max out my hot water to 52c overnight which is the least effcient way of doing it but its far cheaper.
Its worth noting that R290 heat pumps are not really any more effcietn than a decent (modern) R32 heat pump in the normal heating range (e.g. sub 50C flow temperatures at dt5). The main advantage of R290 is it can go hotter but the effciency drops off when doing so, for example, you can get your hot water up to 60C on the heat pump alone alone where as R32 you need an immersion to do the gap between 52C and 60C. For a 180litre tank, thats less than 1kwh on the immersion and thats only once per week to do legionella cycle.
The disadvantage of R290 is it cant be installed near any vents or drains which are below the heat pump under current regs. My heat pump is installed right next to a air brick for my cavity walls so I'd have to deal with that if I go R290 next time round.
I'm thinking Daikin may have made other changes in the new model, apart from the gas - increasing efficiency and improving longevity.
Do you mean you heat the water in your water cylinder to 52C?
If you had an R290 heat pump, you could heat up the water to say 60C overnight - wouldn't that save you even more money during the day?
Do you mean you heat the water in your water cylinder to 52C?
If you had an R290 heat pump, you could heat up the water to say 60C overnight - wouldn't that save you even more money during the day?
There is only so much they can do, Daikin are not exactly new to the heatpump game and you are up against physics. The altherma 3 is already about as good as it gets on R32 (inverter compressor, low modulation etc), the change to R290 was all about going hotter and using a gas with lower global warming potential, it's not being more effcient.
Yes
I don't run out when heating to 52 so going hotter wouldn't save me anything. I could get away with less, quite a bit less in reality but it's only only 7p/kwh and I only use about 1kwh overnight to heat it back up to 52C. It also means if I want to have a long and hot shower after Mrs Sk8 has done what ever takes her ages to do in the shower, I can and not have to worry about it running out.
You can set the heat pump to automatically re-heat the cylinder when the temperature drops below a certain threshold. I've disabled it to prevent it re-heating during the day which will either consume my battery power which I can export to the grid or use peak time electric in the dead of winter (Dec/Jan).
You'd save even more money by not running a Legionella cycle, unless your at risk it's not really required, especially if storing at around 50°c or using the entire tank frequently.
Our tank is set at 50°c and I never run a Legionella cycle, only time I heat to 60c is in a free power hour.
Legionella and Hot Water Safety: The Right Temperature for Your Home | Heat Geek
Understand how to prevent legionella growth, avoid scalding and save energy by setting the right hot water temperature.
www.heatgeek.com
You'd save even more money by not running a Legionella cycle, unless your at risk it's not really required, especially if storing at around 50°c or using the entire tank frequently.
Our tank is set at 50°c and I never run a Legionella cycle, only time I heat to 60c is in a free power hour.
Legionella and Hot Water Safety: The Right Temperature for Your Home | Heat Geek
Understand how to prevent legionella growth, avoid scalding and save energy by setting the right hot water temperature.
Correct and to be honest, I am not even sure why I still run it. At 50C, the legionella gets killed off after 2 hours anyway which the tank will be when heated to 52C (above the coil).
Do you think I should get a 180 or 200L cylinder? There are 2 adults living in the house, but sometimes we get up to 4 guests for a few days.
Also, with a Daikin heat pump, Octopus can fit a Joule slimline or a Daikin regular cylinder - which one do you think is better?
Also, with a Daikin heat pump, Octopus can fit a Joule slimline or a Daikin regular cylinder - which one do you think is better?
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Get the biggest one that will fit in the space you have available IMO.
Otherwise they are much of a muchness IMO. There might be an efficiency and/or heat loss difference but you are talking about relatively small differences on hot water which makes up a relatively small impact on your running costs.
The bigger tank means you can run it at a lower temperature which is more efficient and you’ll get the same amount of stored energy.
The flip side is how much useful cupboard space will you get back going for the slim cylinder (which I assume is smaller in volume)?
Otherwise they are much of a muchness IMO. There might be an efficiency and/or heat loss difference but you are talking about relatively small differences on hot water which makes up a relatively small impact on your running costs.
The bigger tank means you can run it at a lower temperature which is more efficient and you’ll get the same amount of stored energy.
The flip side is how much useful cupboard space will you get back going for the slim cylinder (which I assume is smaller in volume)?
We have a five bedroom house, we went with a 188 litre tank (space constraints), but there is only three of us here for most of the time, sometimes my daughters boyfriend stays, sometimes my other daughter visits.
We've never run out of hot water, even when one of us has had a bath, and the other two showered in quick succession.
I do have mine set to reheat as soon as required, and it only takes about 25 to 30 minutes, flow temperature peaks at 60c and we have the tank set at 50c.
Yesterday had two hot water cycles, and used 3.5 kWh with a COP of 3.4, cost 24p.
Yesterday heating COP was 5.79 and combined 4.55
We've never run out of hot water, even when one of us has had a bath, and the other two showered in quick succession.
I do have mine set to reheat as soon as required, and it only takes about 25 to 30 minutes, flow temperature peaks at 60c and we have the tank set at 50c.
Yesterday had two hot water cycles, and used 3.5 kWh with a COP of 3.4, cost 24p.
Yesterday heating COP was 5.79 and combined 4.55
I have a 180L slimline tank as it had to be lifted up to the loft space. Way too big for my use case in a 2 bed mid-terrace but Octopus sized it for a full house. I only need 48C water temp for my needs which happens at 1pm to avoid the worst cold damp mornings. I'm on the Cosy tariff so no cost advantage for an early morning heating schedule. I do have a re-heat set to a lower temp in the early hour time slot for when it gets colder but this will be my first cold heating season so this may change.
Currently I have a heating schedule to match the Cosy tariff so the HP will heat during the 3 cheap periods with a setback to avoid heating during the most costly 4pm-7pm time period. I've read the Heat Geek advice about not using a thermostat to control temps but to adjust the WD curve to match the heat loss of the house. I'm sure it's possible but I'm ging to need some time running my Daikin through winter to have a play with this.
Currently I have a heating schedule to match the Cosy tariff so the HP will heat during the 3 cheap periods with a setback to avoid heating during the most costly 4pm-7pm time period. I've read the Heat Geek advice about not using a thermostat to control temps but to adjust the WD curve to match the heat loss of the house. I'm sure it's possible but I'm ging to need some time running my Daikin through winter to have a play with this.
It's my first winter as well, so will be interesting.
I'm certain my radiators haven't been balanced, so there's that to do and the heat curve is set to 0.8, which is working fine at the moment. I also need to finish ading more insulation to the loft.
I'm certain my radiators haven't been balanced, so there's that to do and the heat curve is set to 0.8, which is working fine at the moment. I also need to finish ading more insulation to the loft.