Hi. 

I have a 12kw Samsung ASHP  with Hive thermostat that my installers (greener living) don't seem to be able to make work consistently or economically.

The whole system is installed into the loft with the thermostat down in the L shape living/dining room. about 2 weeks ago the bedroom it sits over can hear what i think is the expansion vessel working and its very annoying when trying to sleep! - wasn't that loud until then so not sure why it is loud all of a sudden)

It's been installed since end of December now and i'm struggling with it not heating up last two rads on the system (which are downstairs in the living/dining room). They have added a second pump onto the return side of the system and that seemed to help for a few hours when first installed but now not coming back on again. if i turn the TRV off on others earlier in the system off the last two do get warm but even then not hot)

so the system is taking a lot of KWH to run to get the living room up to temp and then the temp is dropping quickly once it reaches 18 degrees as not enough ambient heat from the working radiators on the system.

i have had to take to turning thermostat down as couldn't afford the £15 per day electricity bill it was generating.

We had solar installed at the time too (16 x 405w panels) and even that isn't working right at just 1-1.8kwh per day generation at the moment which seems extremely poor for this size of system that works on PV and min 7 hours daylight at the moment.

All in all feel at my wits end with it all

Dealing with your solar PV problem first, a approximately 6.5kW array should be producing more that 1-1.8kWh at the moment, our 4kW array produced 3.2kWh yesterday. Is there any form of shading on your panels? What is their orientation and angle?

Now on to your central heating.

Have your radiators been bled and the system balanced? All TRV's, except those in bedrooms, should be fully open. Is your system operating in weather compensation mode or fixed leaving water temperature?

Posted by: @derek-m

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Is your system operating in weather compensation mode or fixed leaving water temperature?

The mention of the whole ASHP setup being in the loft and only the Hive being downstairs makes me pretty sure it's the latter. Also, it's Greener Living, who never finished our installation (never came close to filling out the commissioning sheet), usually played dead when contacted and screwed up connection of a friend's existing solar panel.

@lfranklin - complain early. This sounds like you had a worse designer than we did, in addition to Greener Living's rather rushed installers. It sounds like it needs some modifications, or at least an explanation of what they're playing at fitting a Hive (or did you request that?) instead of using the Samsung controls. Then again, we've had a few £15+ days and I don't know the size of your house.

@mjr I have been complaining weekly at the moment. 

Like I said they have been back and added the secondary pump on return side.

The hive was installed the Samsung itself doesn't have an app that I'm aware of. the controls are in the loft where the tank etc is.

@derek-m they have been bled and I've been around and bled myself also. They weren't balanced at all. So I've been around upstairs and throttled down some of the lockshields to try and force heat downstairs.

I don't know if working in weather compensation mode or not. How can I tell/check please?

We had a Daikin Altherma 3 High Temp Split HHT (R32) installed in November 2021. It has never functioned well. We have had three Daikin engineer visits and multiple visits from the installers. The last Daikin engineer visit was yesterday. He left the unit in installer mode and since then it has neither heated the house nor the hot water. In fact it seems to have stopped working altogether. The control panel is lit up. I have checked what it is supposed to be doing and the schedule of heating remains on. However in looking through the various information sections the actuators are all showing off and I cannot get them to remain on. I have restarted the whole machine twice by turning off the outside (master) switch but that simply starts it for about 10 seconds when it shuts down again.  

I have called Daikin this morning and asked for someone to visit urgently, both my wife and I are pensioners so we count as vulnerable. 

Any ideas anyone?

SO the Daikin people called back and asked me to reset the thermostat from 20 to 23 to increase the requested load on the system. Success! The system booted up the pump and the compressor (eventually) turned on and the radiators are returning to a temperature we can live with. 

I cannot believe that a so called 'Engineer' would leave without confirming that the system was actually operating correctly. When I was a boy that would have at least been a 'court marshal' if not shooting offence. 😋 

Who trains these people?

@derek-m lol if only!!