Posted by: @webcmg

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What's your setup/house size etc? DO you have heat exchanger and buffer tank?

See the thread "14kW Midea ASHP in an old leaky building" (<=link), lots of info there. Small old three bed listed cottage, and yes I do have a plate heat exchanger, these have much discussed as to their pros and cons. Mine has yet to get the chop. No buffer tank.

@colin have you got any pictures of your installation you could share please? Do you have any room stats?

@webcmg

Here you go. What's your average flow temp now you've lowered the Heat Curve to 0.4?

@colin you do have a VMZ AI panel, any chance you could compare your settings to mine posted above?

Consumption and average flow temp has come right down, but the external temperature has also gone up a lot.

I bet your kwh usage is still half of these values... but my COP does look a little bit better? (I'd prefer lower kWh usage tbh!) 

@webcmg

What integration are you using for the outdoor temperature? I've just added OpenWeatherMap to try and get these values but not sure if they're the most accurate. 

My VMZ AI panel settings are below (where mine are different I've highlighted in bold):-

• Comp. hyster.CH = 7k
• Max. re. feed head = 900 mbar
• DHW mode (Normal) - eco
• Max, anti-cycl. time = 5h
• Conf. heat. build. pump = Auto
• Conf. DHW. build. pump = 100%
• Compr. current limit = 25
• Compr. noise. reduct. = 40%
• Intermed heat exchange = No

What do you see if you set your graph history to show electricity usage vs flow temperature? 

Hows how mine looks from the 19th to right now.:-

@colin for external temperature I have two methods currently. The first is the Vaillant external temperature sensor via a custom Vaillant HACS integration on Home Assistant. The second is a Tado TRV which I've temporarily put in my outside letter box... both seem in sync in terms of readings. 

I'll have a look if I can plot power usage vs flow. I seem to recall some incompatibility in these datasets in HA for some reason... 

Thanks for the setting info. Setting  DHW to eco seems like a no brainer, and the intermediate heat exchanger setting makes sense because you don't have one. Any idea what the other settings mean? 

Posted by: @webcmg

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@colin have you got any pictures of your installation you could share please? Do you have any room stats?

I've got two Ambisense TRVs in our two coldest rooms. They're smart enough to increase the flow temp on the Arotherm+.

I've also got two cheap Chinese Zigbee smart TRVs for the kids room but I'm just using them dumb and set them to be fully open.

@webcmg I don't get the Vaillant external Temp entity with my HACs so will rely on Openweathermap for now, not sure why, maybe because my external sensor is wireless. I'm not familiar with those VMZ settings as I've never touched the settings in the VMZ AI Panel. I've only ever adjusted the settings from the Sensocomfort. 

You can get all the graphs in the same page using the HA History tab, for example:-

Hi @colin any chance of a graph of your Jan usage please? I've reduced the curve to 0.35 setback 18 deg (running weekdays until 16.00 then 19.5 deg until 21.00) and 19.5 all weekend. Room temps vary from 16-20 degrees (possibly due to variable insulation that's being addressed next week). Daily heating kwh usage has been between 11 and 35 in Jan. Whereas it was between 13 and 70 in December, but it was colder at times in December. Hence why I'm interested in your consumption... Thanks. 

@webcmg

Once you get your insulation sorted it sounds like you're on the right track, our room temps are a more comfortable >=21ºC

Here's our January consumption below, something to bear in mind is we've had our temps set higher than usual and we're in an exposed part of Scotland up a hill.

@colin thoughts on my COP? Total 2022 is from March 2022 to Jan 2023. Looking forward to seeing how figures compare to last year now that it seems to be working more efficiently. Changing DHW to Eco mode seems to have made a big difference given the low ambient temperature... 

Hi all

Just read this through this topic and looks like there are alot of yous with the same issue as i have and hopefully someone can help with the high running costs i'm experiencing. 

Some basic background information, i have a timber frame kit /block bungalow, heating area 267m2 with underfloor heating, highly insulated, A rating EPC. Replaced a 14 year old ground source pump with a Vaillant Aro Therm 12 kw air source pump approx 3 months ago and haven't touched any settings that the installation team set up. I have tried various timings, on all time / timer etc to try and get this running as efficiently as possible. DHW set at 48 deg on manual to top up when water drops 5 deg. All underfloor manifolds open and inside thermostat set at 21.5 with fallback at 21 deg. I normally run this for 4 hours  at night on the cheap tariff to heat the house which retains the heat for about 10 hours then it kicks in for approx 4-5 hours, this is the time it takes to increase the inside temp by  .5 to 1 deg.

What i have noticed is this, no matter what the outside temperature is, i've seen it at -3 ranging to + 9 deg, the flow temperature is always 32-38 deg, i haven't seen above 38 deg no matter how long the pump has been running. When heating DHW, i've seen the flow temp up as far as 69 deg which tops up the 300 ltr water tank in about 30 mins. Another thing i've noticed too is that the pump runs at 5 kw/ hr all the time, again no matter how long the pump has been running, it ran for 7 hours solid once, all at 5 kw/hr. Is this correct as i would have thought that when it gets up to temperature it wouldn't take so much energy to sustain that temperature. Am i right or have i got this all wrong? I'm hoping a few setting adjustments will remedy this running costs but not holding out much hope. I am grateful that i have solar and battery storage to compensate for the running of this pump, if not my December bill would have been £980 which is a bit worrying. I appreciate electricity prices have risen dramatically however this pump is running way more expensive than my ground source pump did. My old system used to run at 34 deg and that kept my whole house at 22 deg where now i have cold ceramic floors at this flowrate temperature which i just can't understand. 

Any input would be appreciated. 

Thanks in advance.