I've  had a look through my LG ThermoV settings and I haven't been able to find a weather compensation setting. It's not in the handbook either. We did try the AI settings about a year ago, but the electricity consumption went up again (nearly doubled) in the 3 days we tried it for so I don't want to do that again in a hurry... Does anyone know if it's called something else on the LG?

Posted by: @pumpo-sorcerer

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I've  had a look through my LG ThermoV settings and I haven't been able to find a weather compensation setting. It's not in the handbook either. We did try the AI settings about a year ago, but the electricity consumption went up again (nearly doubled) in the 3 days we tried it for so I don't want to do that again in a hurry... Does anyone know if it's called something else on the LG?

https://forum.buildhub.org.uk/topic/30611-lg-therma-v-r32-monobloc-settings/

There is a wealth of LG Therma V chitchat on buildhub

@hughf Figures I can only dream of - both that they are so low and you can get that information out of your ASHP. The Grant produces no accessible data.

With Derek's help I fettled the Weather Compensation curve  properly earlier this year but it seems my issues may be more fundamental and related to the installation.  We have thermostats (as limiters) in every room although they are set to the same temperature everywhere all the time, but with downstairs being warmer than upstairs. They all cut out anyway when the timer switches the ASHP to heating the water, so never show the right time. A strange way to wire them up.  Downstairs is set to 19 deg and upstairs usually finds a level of about 17 deg, even without the UFH coming on.

It's costly getting heating engineers (you can soon spend £00s with them) around and even then not being sure they can effect fundamental improvement. My inclination is to put up with it until I probably have to replace the ASHP within 5 years (it is now 6 years old). Then I should be able to make a better assessment of both the pump and the installer to select to do a ground-up new installation (except for the UFH pipework). Perhaps by then there will be both improved, consumer oriented ASHPs and a better body of installers with the required skills who don't think of them like a gas boiler.

It is a sad comment on the currrent state of the industry that consumers, such as many of us on this forum, have to develop such a level of understanding of these systems to avoid ending up with one that doesn't deliver on their potential. Imagine if running a car was as complex.

Hopefully next week the weather will be more like last December and daily usage will return to no more than the 45 kWh we achieved then. Still double your figures though, Hugh.

So, if not Grant, what current make(s) of ASHP would others recommend?

Mike

@mike-patrick Mike, those figures aren't from my install, they are from the DIY install done by Glyn Hudson, who is a software developer on the Open Energy Monitor project. All that data is available through the addition of a Open Energy Monitor heatpump monitoring package that includes electricity and heat meters, along with 10yrs of data storage and graphing.

It just goes to show that this technology isn't in any way complex to install and operate correctly, a good result is purely down to how big your radiators are and thus how low your flow temperature is.

There's nothing wrong at all with the Chofu ASHP, all you need is to pay a plumber to re-plumb it directly and get it running from the Chofu controller. Heck, if you're vaguely competent you could re-plumb it yourself. It's really not complex at all.

If you want to choose a brand, I went with Cool Energy, who's units are made by SPRSUN in China. They are built around the excellent Carel commercial refrigeration platform. Chris, the MD, is super helpful and technical, with a background in commercial refrigeration software. They are cheap, well built, and seem to perform well.

Posted by: @mike-patrick

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So, if not Grant, what current make(s) of ASHP would others recommend?

There clearly are differences between them, but I would say generally it's the system design that matters more than what is outside. I spent a while looking over different COPs on the Keymark website, and concluded that whilst there are differences, they are generally small between heat pumps of a similar age. 

Then if you're not picking purely for efficiency, there are so many other factors that it's hard to recommend one, and even if one could, very few have experience with multiple manufacturers and models. 

In the end I say you should pick the installer and installation carefully, not the heat pump. 

@oswiu I'm not quite sure as only had been in the house for approx a year and was going off filling the oil tank which was approx every other month to keep us with hit water and timed heating. Narrow drive so specialist tanker which added to cost but was spending anywhere £200-300 for 250 litres. The oil boiler was on its was out so circumstances made us decide on the ashp.

@hughf I think that's part and parcel of our installation going from the garage, through a long run of a barely used probably under insulated spare room (old Drayton radiator trv set to iii). It's generally cool in there as above the garage/dormer windows and old glazing, before reaching the main areas of the house.

Guess I'll be looking at further floor/ceiling and insulating the eaves and pipes further, alongside an insulated frame for the gubbins in the garage, and look at a newer radiator and better performing trv.

TBF the pumps themselves are situated in an ?ideal position on a south facing wall but again I wonder if there is anything else I can further add outdoors to improve efficiency....maybe upgrade the pipe lagging on the outside? 🤷‍♂️

If you want to improve the efficiency you should remove any hydraulic separation between the ashp and the heating circuit, and make sure that all external thermostats are removed. The system must be operated directly, using the original controller for any room temperature influence required.

Basically, the chofu controller should be the centre piece of your house and install 🤣

Posted by: @bretix

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@oswiu I'm not quite sure as only had been in the house for approx a year and was going off filling the oil tank which was approx every other month to keep us with hit water and timed heating. Narrow drive so specialist tanker which added to cost but was spending anywhere £200-300 for 250 litres. The oil boiler was on its was out so circumstances made us decide on the ashp.

I believe oil usage in litres multiplied by 10 to be your heating requirement in kWh, so with 6 lots of 250L per year that suggests you need 15, 000kWh. Even if there's a lot of uncertainty in those assumptions, your installation still sounds like overkill by a factor of two, but then as @HughF calculated, your electricity usage does seem to be very high so maybe your installation is rightly sized. It's hard to say. 

@hughf Thanks for this. I would love to get all that data but I see the Open Energy kit is about £600 and would be beyond my level of expertise to install.

Interestingly reading this thread prompted me to compare the Chofu manual with my installation. In the manual it shows setting up of the on/off timing of the DHW and UFH as being done within the remote control unit. My Grant system has that unit (I've adjusted Weather Comp in there before) but I also have a standard Honeywell Hot Water v Heating time switch next to it. That is what controls the timing of each. What is the point of this if the Remote Control Unit has that functionality?

I agree with yours and other comments on here. The key to getting ones ASHP working correctly if, like me, you're not suitably technically minded is to find a heating engineer who is. Since having discovered that our original installer (now no longer even MCS certified) was not one of these, this has remained my key challenge in making more progress. I need to identify someone who is any good, before I hire them to do any work on my system.

Mike

Posted by: @mike-patrick

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The key to getting ones ASHP working correctly if, like me, you're not suitably technically minded is to find a heating engineer who is.

Quite! And in your case they don't have to be a heating engineer constrained by MCS regulations. They simply need to be knowledgeable and proficient.
Have you considered looking for a community-energy group in your area? They may be have relevant expertise and know of local engineers.

Whereabouts are you, geographically?

Posted by: @transparent

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Posted by: @mike-patrick

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The key to getting ones ASHP working correctly if, like me, you're not suitably technically minded is to find a heating engineer who is.

Quite! And in your case they don't have to be a heating engineer constrained by MCS regulations. They simply need to be knowledgeable and proficient.
Have you considered looking for a community-energy group in your area? They may be have relevant expertise and know of local engineers.

Whereabouts are you, geographically?

It can also be quite useful to carry out a few simple tests oneself, which can often identify the root cause of the problem, or at least the main area of concern. More often than not an ASHP will get the blame for under performance, whereas the culprit may be lurking in a different part of the system.