@suzer 

Hi and welcome to the forum.  We have a 14kW Ecodan too.  Have you had to make many changes compared with how the system was handed over?

@Kev M

We now have our heating on 24/7 with no set backs overnight. We tried all kind of tests running it different times & found it most efficient this way.  Still costs heaps due to electricity prices but at least the house is warm!

We changed our compensation curve as the flow temp was quite high even on mild days. We do have really high return flow temps which we have never got to the bottom of. 

What we have yet to crack is our DHW. We have the tank heated once a day for hour and half to 48 degrees. This does 2 showers, small amount washing up and evening abolutions. However we only have the circulation pump on for 5 mins morning & night so washing hands in cold water during day. We have to put boost on for shower & washing up which is a bit of a pain. Having dhw on all the time with tank reheating cost a fortune hence why we do the above. It costs about 2 kWH a day.

How do you manage DHW?

@suzer high return flow temperatures would mean you aren't putting that much heat into the house.

On the DHW, honestly those numbers are fine. We leave ours on constant and use around 9kw per day for showers, hot water and baths for 2 children. If you wanted to get the best outcome you could heat the hot water around mid-day as you'd get the best COP

There’s enough water for us but it isn’t available to the tap unless we switch the circulation pump. I miss “on tap” hot water but don’t want it sat in the pipes getting cold

@suzer I am confused. It wont circulate around the pipes unless its the end tap is being used. So I don't really see the issue. It would be the same with any boiler, Gas or ASHP. Is the tank not unvented? An unvented tank shouldn't need a pump as it becomes pressurised 

@suzer 

why do you have to switch on the circulation pump to get HW?  I've never heard of that?  There isn't much water in the pipes, it's nearly all in the tank. Our tank loses about 1 degree every 2 hours so not a lot. We use almost no hot water (electric showers/dishwasher) and even if I keep it on 24 hrs it uses about 2kWh/day.

It's still a good idea to limit when the ASHP produces HW because if you have it on 24/7, when you use a bit it will stop the heating to heat the tank up again and interrupting your heating like that affects efficiency.. 

@kev-m a circulation pump is used to circulate hot water around a loop to reduce the wait at a tap. presumably the cylinder has moved further away from its original location

@alec-morrow 

sorry, I know that but @Suzer was suggesting she needed to switch the pump manually to get HW.  That's what I've never heard of and why would this be designed into a new build?  Having plenty of hot water on tap (literally) is one of the basics for an ASHP.

We have an ecodan ashp.

It takes forever for hot water to come out of our kitchen sink. Showers seem ok they seem to be hot straight away.

We are planning on getting a hot water tap as this will obviously cost but won't be wasting loads of water.

We keep our water on all the time as with the heating. Our water is on eco mode setting, set to 44 degrees. Last night tank was 35 degrees and I wanted a shower, being very nesh 🙄 that was too cold for me. I turned off the heating to give water priority and upped water temp on mel cloud app within 15mins temp had risen to 41.5, enough for a quick shower.

I could've put the dhw/ immersion on it wouldn't have been on long as it was as it was only coming up from 35 degrees.

@sand what kind of taps do you have? Mixer taps, even on hot actually mix cold water in. That's why the water is never as hot as with single taps. 

@kev-m 

We had hot water on all the time when we moved in and got hot water whenever we needed. However it cost a lot of money!  So we only heat once & have circulation pump timed to come on when we are likely to need it. What I don’t know is can you have circulation pump on all the time but the actual heating of the water once?