@davidalgarve I should have made it clear that my COP is NOT down since using Havenwise with Shelly sensor. It's much the same as prior when on pure WC.

I have searched for local installers to come and inspect my installation to see if anything can be done to improve matters. Never get replies. I've asked here for recommendations of a local installer without luck. I'm pleased with the way the system works in that the house is lovely and cosy, but would very much welcome better COP and some cash savings.

@jamespa Hello James and thank you for your interest.

Before attempting to answer your questions, I feel I should make it clear that my problem is that I am uncertain how to get levels of comfort that I had last year after making changes that I expected would show benefits. Subjectively, the radiators are not getting as hot as last year and it seemed wrong to increase the  higher end of the weather compensation curve more than I have already done.

To your questions:

The figure and quote of: "35.91 kWh/ sq m per year. That is a very good result ( energy efficient house)" is a quote from my MelPump app and I don't know how it is calculated. Consumption in eg, December 2024 was 710kWh and December 2025 914kWh (all per the FTC6) but DHW had been added by then.

The house construction is typical 2012 Algarve with RC concrete frame; hollow blocks and concrete floors and ceilings. When we bought it 20 yeras ago, we added insulation where practical and double glazing throughout. Personally, I would not have classified it as well insulated and i would like to do more. 

"+5" Once having set up the weather compensation, the FTC6 gives you the option of simply modifying it in increments of 1 to +9 or -9. With my curve set at 27C @ 18C, I am also on +5. I am not sure if this actually pushes up the curve by 5C. but it does seem a high setting and I believe is more than I was using last year.

Emitters are Roca aluminium and both the lockshield valves and Tado's are fully open. The radiators were not changed when we switched from LPG boiler to ASHP in December 2021. The contractor set it up on fixed temperature and it was very expensive and not comfortable, (timed operation). In the second year I changed it to weather compensation and since then, comfort improved significantly. As I mentioned earlier, I do not believe the radiators are getting as hot as last year, but don't have any data to back this up. It almost seems as though something is controlling it at 19.5-20C - see the output reading from the PAR 60 

Settings: As above- "High" setting 27C instead of 25C and at +5

Volumiser is in return, see sketch:

Flow rate: I have tried Pump speed 3 - 11 l/min and 5 - 16l/min and didn't see a lot of difference.  The Ecodan pump (Grundfos) is inside the cabinet. I did check the specifications and the pump I removed (also Grundfos) had a similar performance spec, but had  no speed control.

Scale: Here is a shot in last 24 hours but OAT's have increased after weather events and lots of rain:

I hope that helps!

@f1p Yes of course but may need some guidance.

However we are having an unusual warm spell after the last two weather events moved through. Would it be better to wait for it to cool somewhat?

Posted by: @davidalgarve

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@f1p Yes of course but may need some guidance.

However we are having an unusual warm spell after the last two weather events moved through. Would it be better to wait for it to cool somewhat?

You can select a date in the past which perhaps reflects best the issue you see, and then Share that day - see the buttons to press outlined in red boxes:

Thanks for the info.  Volumiser configuration should be OK, a little concerned the rads are original it suggests some may be undersized.

Posted by: @davidalgarve

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Consumption in eg, December 2024 was 710kWh and December 2025 914kWh (all per the FTC6) but DHW had been added by then.

OK, difficult to compare

Posted by: @davidalgarve

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Emitters are Roca aluminium and both the lockshield valves and Tado's are fully open.

Are they all fully open, has any attempt been made to balance or do they just happen to be balanced?

Posted by: @davidalgarve

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Flow rate: I have tried Pump speed 3 - 11 l/min and 5 - 16l/min and didn't see a lot of difference.  The Ecodan pump (Grundfos) is inside the cabinet. I did check the specifications and the pump I removed (also Grundfos) had a similar performance spec, but had  no speed control.

Is 5 the highest it will go.  16l/min is only 5.6kW at DT5, which may explain why your DT is higher than I would hope and of course this also reduces the output at any given flow temperature.  Have you checked the filters (there may be a fine mesh one inside the casing as well as a magnetic one outside).  Do you know what the flow rate on the secondary side (emitter side) was last year - I guess not.  Is it 16l/min constant or is this the flow rate at current OATs, going up if the OAT goes down?

These are  the only things which currently stand out to me as suspect.  That flow rate really is too low for 12kW, mine, by comparison, is 18-20l/min for 7kW.  Im surprised the heat pump isnt complaining.

How old is the heat pump?

@jamespa 

Radiators:They were balanced to some extent, but I opened them up when it appeared that there was low flow. I have subsequently adjusted a few radiators in an attempt to increase heating to downstairs master bedroom.

Pump Speed: Yes 5 is maximum, but I have found an old note I had made which referred to 23 l/min at Setting 5 so can't understand the 16 l/min now. On Setting 3 it seems fairly consistent at  11 l/min

I have not yet checked filters.

I am wondering about 2 other matters that I have turned up and would appreciate comments from a Mitsu installer:

1 - MelPump not that  Pump 1 and Pump 2 being switched On, (Pump 2 is probably the one removed), but I cannot find the switch or dip switch to switch this off.

2 - Looking through the dip switches settings, dip switch 2-6 is for a buffer tank and should be 'On' if one installed and 'Off' if no buffer tank. Mine is 'On'. 

The heat pump was made August 2021 and installed December 2021

Finally, surely there must be some significance in the fact that the room temperature, as relayed from the wireless controller, shows a steady 20C when everything else is moving significantly

@davidalgarve yes the 20c readings is an error. Ill try to find the solution i used and post back

Posted by: @davidalgarve

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Pump Speed: Yes 5 is maximum, but I have found an old note I had made which referred to 23 l/min at Setting 5 so can't understand the 16 l/min now. On Setting 3 it seems fairly consistent at  11 l/min

I have not yet checked filters.

Check them.  Filters, particularly the fine mesh filter if you have one (it may be inside the case) block up quickly.  Mine blocked up to the point that the heat pump complained after less than 2/3rds of a season!  You have replumbed, expect this to cause blockages.

Posted by: @davidalgarve

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I am wondering about 2 other matters that I have turned up and would appreciate comments from a Mitsu installer:

1 - MelPump not that  Pump 1 and Pump 2 being switched On, (Pump 2 is probably the one removed), but I cannot find the switch or dip switch to switch this off.

2 - Looking through the dip switches settings, dip switch 2-6 is for a buffer tank and should be 'On' if one installed and 'Off' if no buffer tank. Mine is 'On'. 

(1) it may be a dip switch or it may be in the installer menu

(2) I would suggest it should be off!

Posted by: @davidalgarve

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Finally, surely there must be some significance in the fact that the room temperature, as relayed from the wireless controller, shows a steady 20C when everything else is moving significantly

 

Yes I agree.  Is it at all possible you have some sort of room influence active, or that its turning a pump off?

@bontwoody Hi bontwoody. The PAR 60 wireless controller cost a lot of time and agro to install and I wish that I had never considered Adaptive. 
Although I am back on weather compensation is there any possibility that the PAR 60 is still influencing control?

HavenWise reported similar but put it down to granularity.

@jamespa The only possible thing is the PAR 60 which should have no influence whilst on weather compensation and I have it set at 38 C, but who knows?

@davidalgarve Ive had a look at my emails but cant find it. My recall is that there was a dip switch that needed to be changed to activate the temperature reading of the remote controller and that 20C was being reported as the original sensor wasnt being used.

@f1p cant you put me out of my misery please? 🙂

Finally, surely there must be some significance in the fact that the room temperature, as relayed from the wireless controller, shows a steady 20C when everything else is moving significantly

I presume you only have a single zone system as there is no Indoor Temp #1?

I would like to know what input temperature is set in "Initial Settings" > "Room Sensor Settings" > "Sensor Settings" > Zone 1 > Sensor Setting > "Room RC1" should be in use

20C static is suggesting to me a disconnected input